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# ODBC 

## 1. 功能介绍

IoTDB ODBC 驱动程序提供了通过 ODBC 标准接口与数据库进行交互的能力，支持通过 ODBC 连接管理时序数据库中的数据。目前支持数据库连接、数据查询、数据插入、数据修改和数据删除等操作，可适配各类支持 ODBC 协议的应用程序与工具链。

> 注意：该功能从 V2.0.8.2 起支持。


## 2. 使用方式

推荐使用预编译二进制包安装，无需自行编译，直接通过脚本完成驱动安装与系统注册，目前仅支持 Windows 系统。

### 2.1 环境要求

仅需满足操作系统层面的 ODBC 驱动管理器依赖，无需配置编译环境：

| **操作系统** | **要求与安装方式**                                                                                                                        |
| -------------------- |------------------------------------------------------------------------------------------------------------------------------------|
| Windows            | 1. **Windows 10/11、Server 2016/2019/2022**：自带 ODBC 17/18 版本驱动管理器，无需额外安装 <br>2. **Windows 8.1/Server 2012 R2**：需手动安装对应版本 ODBC 驱动管理器 |

### 2.2 安装步骤

1. 联系天谋团队获取预编译二进制包

二进制包目录结构：

```Plain
├── bin/
│   ├── apache_iotdb_odbc.dll
│   └── install_driver.exe
├── install.bat
└── registry.bat
```

2. 以**管理员权限**打开命令行工具（CMD/PowerShell），并运行以下命令：（可以将路径替换为任意绝对路径）

```Bash
install.bat "C:\Program Files\Apache IoTDB ODBC Driver"
```

脚本自动完成以下操作：

* 创建安装目录（如果不存在）
* 将 `bin\apache_iotdb_odbc.dll` 复制到指定安装目录
* 调用 `install_driver.exe` 通过 ODBC 标准 API（`SQLInstallDriverEx`）将驱动注册到系统

3. 验证安装：打开「ODBC 数据源管理器」，在「驱动程序」选项卡中可查看到 `Apache IoTDB ODBC Driver`，即表示注册成功。

![](/img/odbc-1.png)

### 2.3 卸载步骤

1. 以管理员身份打开命令提示符，`cd` 进入项目根目录。
2. 运行卸载脚本：

```Bash
uninstall.bat
```

脚本会调用 `install_driver.exe` 通过 ODBC 标准 API（`SQLRemoveDriver`）从系统中注销驱动。安装目录中的 DLL 文件不会被自动删除，如需清理请手动删除。

### 2.4 连接配置

安装驱动后，需要配置数据源（DSN）才能让应用程序通过 DSN 名称连接数据库。IoTDB ODBC 驱动支持通过数据源和连接字符串配置连接参数两种方法。

#### 2.4.1 配置数据源

**通过 ODBC 数据源管理器配置**

1. 打开"ODBC 数据源管理程序"，切换到"用户 DSN"选项卡，点击"添加"按钮。

![](/img/odbc-2.png)

2. 在弹出的驱动程序列表中选择"Apache IoTDB ODBC Driver"，点击"完成"。

![](/img/odbc-3.png)

3. 弹出数据源配置对话框，填写连接参数，随后点击 OK：

![](/img/odbc-4.png)

对话框中各字段的含义如下：

| **区域** | **字段**  | **说明**                                                                                                  |
| ---------------- | ----------------- | ----------------------------------------------------------------------------------------------------------------- |
| Data Source    | DSN Name        | 数据源名称，应用程序通过此名称引用该数据源                                                                      |
| Data Source    | Description     | 数据源描述（可选）                                                                                              |
| Connection     | Server          | IoTDB 服务器 IP 地址，默认 127.0.0.1                                                                            |
| Connection     | Port            | IoTDB Session API 端口，默认 6667                                                                               |
| Connection     | User            | 用户名，默认 root                                                                                               |
| Connection     | Password        | 密码，默认 root                                                                                                 |
| Options        | Table Model     | 勾选时使用表模型，取消勾选时使用树模型                                                                          |
| Options        | Database        | 数据库名称。仅表模型模式下可用；树模型时此字段灰化不可编辑                                                      |
| Options        | Log Level       | 日志级别（0-4）：0=OFF, 1=ERROR, 2=WARN, 3=INFO, 4=TRACE                                                        |
| Options        | Session Timeout | 会话超时时间（毫秒），0 表示不设超时。注意服务端 queryTimeoutThreshold 默认为 60000ms，超过此值需修改服务端配置 |
| Options        | Batch Size      | 每次拉取的行数，默认 1000。设为 0 时重置为默认值                                                                |

4. 填写完成后，可以点击"Test Connection"按钮测试连接。测试连接会使用当前填写的参数尝试连接到 IoTDB 服务器并执行 `SHOW VERSION` 查询。连接成功时会显示服务器版本信息，失败时会显示具体的错误原因。
5. 确认参数无误后，点击"OK"保存。数据源会出现在"用户 DSN"列表中，如下图中的名称为123的数据源。

![](/img/odbc-5.png)

如需修改已有数据源的配置，在列表中选中后点击"配置"按钮即可重新编辑。

#### 2.4.2 连接字符串

连接字符串格式为**分号分隔的键值对**，如：

```Bash
Driver={IoTDB ODBC Driver};server=127.0.0.1;port=6667;uid=root;pwd=root;isTableModel=false;loglevel=2
```

具体字段属性介绍见下表：

| **字段名称**        | **说明**                   | **可选值**                                                                                                                      | **默认值**                |
| --------------------------- | ---------------------------------- |------------------------------------------------------------------------------------------------------------------------------| --------------------------------- |
| DSN                       | 数据源名称                       | 自定义数据源名                                                                                                                      | -                               |
| uid                       | 数据库用户名                     | 任意字符串                                                                                                                        | root                            |
| pwd                       | 数据库密码                       | 任意字符串                                                                                                                        | root                            |
| server                    | IoTDB 服务器地址                 | ip地址                                                                                                                         | 127.0.0.1 |
| port                      | IoTDB 服务器端口                 | 端口                                                                                                                           | 6667                            |
| database                  | 数据库名称（仅表模型模式下生效） | 任意字符串                                                                                                                        | 空字符串|
| loglevel                  | 日志级别                         | 整数值（0-4）                                                                                                                     | 4（LOG\_LEVEL\_TRACE）          |
| isTableModel / tablemodel | 是否启用表模型模式               | 布尔类型，支持多种表示方式：<br>1. 0, false, no, off ：设置为 false；<br>2. 1, true, yes, on ：设置为 true；<br>3. 其他值默认设置为 true。                            | true|
| sessiontimeoutms          | Session 超时时间（毫秒）         | 64 位整数，默认为`LLONG_MAX`；设置为`0`时将被替换为`LLONG_MAX`。注意，服务端有超时设置项：`private long queryTimeoutThreshold = 60000;`需要修改这一项才能得到超过60秒的超时时间。 | LLONG\_MAX|
| batchsize                 | 每次拉取数据的批量大小           | 64 位整数，默认为`1000`；设置为`0`时将被替换为`1000`                                                                                          | 1000|

说明：

* 字段名称不区分大小写（自动转换为小写进行比较）
* 连接字符串格式为分号分隔的键值对，如：`Driver={IoTDB ODBC Driver};server=127.0.0.1;port=6667;uid=root;pwd=root;isTableModel=false;loglevel=2`
* 对于布尔类型的字段（isTableModel），支持多种表示方式
* 所有字段都是可选的，如果未指定则使用默认值
* 不支持的字段会忽略并在日志中记录警告信息，但不会影响连接
* 服务器接口默认值 6667 是 IoTDB 的 C++ Session 接口所使用的默认端口。本 ODBC 驱动使用 C++ Session 接口与 IoTDB 传递数据。如果 IoTDB 服务端的 C++ Session 接口使用的端口不是默认的，需要在 ODBC 连接字符串中作相应的更改。

#### 2.4.3 数据源配置与连接字符串的关系

在 ODBC 数据源管理器中保存的配置，会以键值对的形式写入系统的 ODBC 数据源配置中（Windows 下对应注册表 `HKEY_CURRENT_USER\SOFTWARE\ODBC\ODBC.INI`）。当应用程序使用 `SQLConnect` 或在连接字符串中指定 `DSN=数据源名称` 时，驱动会从系统配置中读取这些参数。

**连接字符串的优先级高于 DSN 中保存的配置。** 具体规则如下：

1. 如果连接字符串中包含 `DSN=xxx` 且不包含 `DRIVER=...`，驱动会先从系统配置中加载该 DSN 的所有参数作为基础值。
2. 然后，连接字符串中显式指定的参数会覆盖 DSN 中的同名参数。
3. 如果连接字符串中包含 `DRIVER=...`，则不会从系统配置中读取任何 DSN 参数，完全以连接字符串为准。

例如：DSN 中配置了 `Server=192.168.1.100`、`Port=6667`，但连接字符串为 `DSN=MyDSN;Server=127.0.0.1`，则实际连接使用 `Server=127.0.0.1`（连接字符串覆盖），`Port=6667`（来自 DSN）。

### 2.5 日志记录

驱动运行时的日志输出分为「驱动自身日志」和「ODBC 管理器追踪日志」两类，需注意日志等级对性能的影响。

#### 2.5.1 驱动自身日志

* 输出位置：用户主目录下的 `apache_iotdb_odbc.log`；
* 日志等级：通过连接字符串的 `loglevel` 配置（0-4，等级越高输出越详细）；
* 性能影响：高日志等级会显著降低驱动性能，建议仅调试时使用。

#### 2.5.2 ODBC 管理器追踪日志

* 开启方式：打开「ODBC 数据源管理器」→「跟踪」→「立即启动跟踪」；
* 注意事项：开启后会大幅降低驱动性能，仅用于问题排查。

## 3. 接口支持

### 3.1 方法列表

驱动对 ODBC 标准 API 的支持情况如下：

| ODBC/Setup API    | 函数功能               | 参数列表                                                                                                                                                                                                                           | 参数说明                                                                                                                                                                                                                                |
| ------------------- | ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| SQLAllocHandle| 分配ODBC句柄           | (SQLSMALLINT HandleType, SQLHANDLE InputHandle, SQLHANDLE \*OutputHandle)                                                                                                                                                          | HandleType: 要分配的句柄类型(ENV/DBC/STMT/DESC)；<br>InputHandle: 上级上下文句柄；<br>OutputHandle: 返回的新句柄指针                                                                                                                            |
| SQLBindCol        | 绑定列到结果缓冲区     | (SQLHSTMT StatementHandle, SQLUSMALLINT ColumnNumber, SQLSMALLINT TargetType, SQLPOINTER TargetValue, SQLLEN BufferLength, SQLLEN \*StrLen\_or\_Ind)                                                                               | StatementHandle: 语句句柄；<br>ColumnNumber: 列号；<br>TargetType: C数据类型；<br>TargetValue: 数据缓冲区；<br>BufferLength: 缓冲区长度；<br>StrLen\_or\_Ind: 返回数据长度或NULL指示                                                                        |
| SQLColAttribute| 获取列属性信息         | (SQLHSTMT StatementHandle, SQLUSMALLINT ColumnNumber, SQLUSMALLINT FieldIdentifier, SQLPOINTER CharacterAttribute, SQLSMALLINT BufferLength, SQLSMALLINT \*StringLength, SQLLEN \*NumericAttribute)                                | StatementHandle: 语句句柄；<br>ColumnNumber: 列号；<br>FieldIdentifier: 属性ID；<br>CharacterAttribute: 字符属性输出；<br>BufferLength: 缓冲区长度；<br>StringLength: 返回长度；<br>NumericAttribute: 数值属性输出                                              |
| SQLColumns| 查询表列信息           | (SQLHSTMT StatementHandle, SQLCHAR \*CatalogName, SQLSMALLINT NameLength1, SQLCHAR \*SchemaName, SQLSMALLINT NameLength2, SQLCHAR \*TableName, SQLSMALLINT NameLength3, SQLCHAR \*ColumnName, SQLSMALLINT NameLength4)             | StatementHandle: 语句句柄；<br>Catalog/Schema/Table/ColumnName: 查询对象名称；<br>NameLength\*: 对应名称长度                                                                                                                                    |
| SQLConnect        | 建立数据库连接         | (SQLHDBC ConnectionHandle, SQLCHAR \*ServerName, SQLSMALLINT NameLength1, SQLCHAR \*UserName, SQLSMALLINT NameLength2, SQLCHAR \*Authentication, SQLSMALLINT NameLength3)                                                          | ConnectionHandle: 连接句柄；<br>ServerName: 数据源名称；<br>UserName: 用户名；<br>Authentication: 密码；NameLength\*: 字符串长度                                                                                                                    |
| SQLDescribeCol    | 描述结果集中的列       | (SQLHSTMT StatementHandle, SQLUSMALLINT ColumnNumber, SQLCHAR \*ColumnName, SQLSMALLINT BufferLength, SQLSMALLINT \*NameLength, SQLSMALLINT \*DataType, SQLULEN \*ColumnSize, SQLSMALLINT \*DecimalDigits, SQLSMALLINT \*Nullable) | StatementHandle: 语句句柄；<br>ColumnNumber: 列号；<br>ColumnName: 列名输出；<br>BufferLength: 缓冲区长度；<br>NameLength: 返回列名长度；<br>DataType: SQL类型；<br>ColumnSize: 列大小；<br>DecimalDigits: 小数位；<br>Nullable: 是否可为空                             |
| SQLDisconnect     | 断开数据库连接         | (SQLHDBC ConnectionHandle)                                                                                                                                                                                                         | ConnectionHandle: 连接句柄                                                                                                                                                                                                              |
| SQLDriverConnect  | 使用连接字符串建立连接 | (SQLHDBC ConnectionHandle, SQLHWND WindowHandle, SQLCHAR \*InConnectionString, SQLSMALLINT StringLength1, SQLCHAR \*OutConnectionString, SQLSMALLINT BufferLength, SQLSMALLINT \*StringLength2, SQLUSMALLINT DriverCompletion)     | ConnectionHandle: 连接句柄；<br>WindowHandle: 窗口句柄；<br>InConnectionString: 输入连接字符串；<br>StringLength1: 输入长度；<br>OutConnectionString: 输出连接字符串；<br>BufferLength: 输出缓冲区；<br>StringLength2: 返回长度；<br>DriverCompletion: 连接提示方式 |
| SQLEndTran        | 提交或回滚事务         | (SQLSMALLINT HandleType, SQLHANDLE Handle, SQLSMALLINT CompletionType)                                                                                                                                                             | HandleType: 句柄类型；<br>Handle: 连接或环境句柄；<br>CompletionType: 提交或回滚事务                                                                                                                                                            |
| SQLExecDirect     | 直接执行SQL语句        | (SQLHSTMT StatementHandle, SQLCHAR \*StatementText, SQLINTEGER TextLength)                                                                                                                                                         | StatementHandle: 语句句柄；<br>StatementText: SQL文本；<br>TextLength: SQL长度                                                                                                                                                                  |
| SQLFetch          | 提取结果集中的下一行   | (SQLHSTMT StatementHandle)                                                                                                                                                                                                         | StatementHandle: 语句句柄                                                                                                                                                                                                               |
| SQLFreeHandle     | 释放ODBC句柄           | (SQLSMALLINT HandleType, SQLHANDLE Handle)                                                                                                                                                                                         | HandleType: 句柄类型；<br>Handle: 要释放的句柄                                                                                                                                                                                              |
| SQLFreeStmt       | 释放语句相关资源       | (SQLHSTMT StatementHandle, SQLUSMALLINT Option)                                                                                                                                                                                    | StatementHandle: 语句句柄；<br>Option: 释放选项(关闭游标/重置参数等)                                                                                                                                                                        |
| SQLGetConnectAttr | 获取连接属性           | (SQLHDBC ConnectionHandle, SQLINTEGER Attribute, SQLPOINTER Value, SQLINTEGER BufferLength, SQLINTEGER \*StringLength)                                                                                                             | ConnectionHandle: 连接句柄；<br>Attribute: 属性ID；<br>Value: 返回属性值；<br>BufferLength: 缓冲区长度；<br>StringLength: 返回长度                                                                                                                      |
| SQLGetData        | 获取结果数据           | (SQLHSTMT StatementHandle, SQLUSMALLINT Col\_or\_Param\_Num, SQLSMALLINT TargetType, SQLPOINTER TargetValue, SQLLEN BufferLength, SQLLEN \*StrLen\_or\_Ind)                                                                        | StatementHandle: 语句句柄；<br>Col\_or\_Param\_Num: 列号；<br>TargetType: C类型；<br>TargetValue: 数据缓冲区；<br>BufferLength: 缓冲区大小；<br>StrLen\_or\_Ind: 返回长度或NULL标志                                                                         |
| SQLGetDiagField   | 获取诊断字段           | (SQLSMALLINT HandleType, SQLHANDLE Handle, SQLSMALLINT RecNumber, SQLSMALLINT DiagIdentifier, SQLPOINTER DiagInfo, SQLSMALLINT BufferLength, SQLSMALLINT \*StringLength)                                                           | HandleType: 句柄类型；<br>Handle: 句柄；<br>RecNumber: 记录号；<br>DiagIdentifier: 诊断字段ID；<br>DiagInfo: 输出信息；<br>BufferLength: 缓冲区；<br>StringLength: 返回长度                                                                                     |
| SQLGetDiagRec     | 获取诊断记录           | (SQLSMALLINT HandleType, SQLHANDLE Handle, SQLSMALLINT RecNumber, SQLCHAR \*Sqlstate, SQLINTEGER \*NativeError, SQLCHAR \*MessageText, SQLSMALLINT BufferLength, SQLSMALLINT \*TextLength)                                         | HandleType: 句柄类型；<br>Handle: 句柄；<br>RecNumber: 记录号；<br>Sqlstate: SQL状态码；<br>NativeError: 原生错误码；<br>MessageText: 错误信息；<br>BufferLength: 缓冲区；<br>TextLength: 返回长度                                                                  |
| SQLGetInfo        | 获取数据库信息         | (SQLHDBC ConnectionHandle, SQLUSMALLINT InfoType, SQLPOINTER InfoValue, SQLSMALLINT BufferLength, SQLSMALLINT \*StringLength)                                                                                                      | ConnectionHandle: 连接句柄；<br><br>InfoType: 信息类型；<br>InfoValue: 返回值；<br>BufferLength: 缓冲区长度；<br>StringLength: 返回长度                                                                                                                     |
| SQLGetStmtAttr    | 获取语句属性           | (SQLHSTMT StatementHandle, SQLINTEGER Attribute, SQLPOINTER Value, SQLINTEGER BufferLength, SQLINTEGER \*StringLength)                                                                                                             | StatementHandle: 语句句柄；<br>Attribute: 属性ID；<br>Value: 返回值；<br>BufferLength: 缓冲区；<br>StringLength: 返回长度                                                                                                                               |
| SQLGetTypeInfo    | 获取数据类型信息       | (SQLHSTMT StatementHandle, SQLSMALLINT DataType)                                                                                                                                                                                   | StatementHandle: 语句句柄；<br>DataType: SQL数据类型                                                                                                                                                                                        |
| SQLMoreResults    | 获取更多结果集         | (SQLHSTMT StatementHandle)                                                                                                                                                                                                         | StatementHandle: 语句句柄                                                                                                                                                                                                               |
| SQLNumResultCols  | 获取结果集列数         | (SQLHSTMT StatementHandle, SQLSMALLINT \*ColumnCount)                                                                                                                                                                              | StatementHandle: 语句句柄；<br>ColumnCount: 返回列数                                                                                                                                                                                        |
| SQLRowCount       | 获取受影响的行数       | (SQLHSTMT StatementHandle, SQLLEN \*RowCount)                                                                                                                                                                                      | StatementHandle: 语句句柄；<br>RowCount: 返回受影响行数                                                                                                                                                                                     |
| SQLSetConnectAttr | 设置连接属性           | (SQLHDBC ConnectionHandle, SQLINTEGER Attribute, SQLPOINTER Value, SQLINTEGER StringLength)                                                                                                                                        | ConnectionHandle: 连接句柄；<br>Attribute: 属性ID；<br>Value: 属性值；<br>StringLength: 属性值长度                                                                                                                                                  |
| SQLSetEnvAttr     | 设置环境属性           | (SQLHENV EnvironmentHandle, SQLINTEGER Attribute, SQLPOINTER Value, SQLINTEGER StringLength)                                                                                                                                       | EnvironmentHandle: 环境句柄；<br>Attribute: 属性ID；<br>Value: 属性值；<br>StringLength: 长度                                                                                                                                                       |
| SQLSetStmtAttr    | 设置语句属性           | (SQLHSTMT StatementHandle, SQLINTEGER Attribute, SQLPOINTER Value, SQLINTEGER StringLength)                                                                                                                                        | StatementHandle: 语句句柄；<br>Attribute: 属性ID；<br>Value: 属性值；<br>StringLength: 长度                                                                                                                                                         |
| SQLTables         | 查询表信息             | (SQLHSTMT StatementHandle, SQLCHAR \*CatalogName, SQLSMALLINT NameLength1, SQLCHAR \*SchemaName, SQLSMALLINT NameLength2, SQLCHAR \*TableName, SQLSMALLINT NameLength3, SQLCHAR \*TableType, SQLSMALLINT NameLength4)              | StatementHandle: 语句句柄；<br>Catalog/Schema/TableName: 表名；<br>TableType: 表类型；<br>NameLength\*: 对应长度                                                                                                                                    |

### 3.2 数据类型转换

IoTDB 数据类型与 ODBC 标准数据类型的映射关系如下：

| **IoTDB 数据类型** | **ODBC 数据类型** |
| -------------------------- | ------------------------- |
| BOOLEAN                  | SQL\_BIT                |
| INT32                    | SQL\_INTEGER            |
| INT64                    | SQL\_BIGINT             |
| FLOAT                    | SQL\_REAL               |
| DOUBLE                   | SQL\_DOUBLE             |
| TEXT                     | SQL\_VARCHAR            |
| STRING                   | SQL\_VARCHAR            |
| BLOB                     | SQL\_LONGVARBINARY      |
| TIMESTAMP                | SQL\_BIGINT             |
| DATE                     | SQL\_DATE               |

## 4. 操作示例

本章节主要介绍 **C#**、**Python**、**C++**、**PowerBI**、**Excel** 全类型操作示例，覆盖数据查询、插入、删除等核心操作。

### 4.1 C# 示例

```C#
/*******
Note: When the output contains Chinese characters, it may cause garbled text.
This is because the table.Write() function cannot output strings in UTF-8 encoding
and can only output using GB2312 (or another system default encoding). This issue
may not occur in software like Power BI; it also does not occur when using the Console.
WriteLine function. This is an issue with the ConsoleTable package.
*****/
using System.Data.Common;
using System.Data.Odbc;
using System.Reflection.PortableExecutable;
using ConsoleTables;
using System;

/// <summary>执行 SELECT 查询并以表格形式输出 root.full.fulldevice 的结果</summary>
void Query(OdbcConnection dbConnection)
{
    try
    {
        using (OdbcCommand dbCommand = dbConnection.CreateCommand())
        {
            dbCommand.CommandText = "SELECT * FROM root.full.fulldevice WHERE time >= 1735689600000 AND time <= 1735690790000";
            using (OdbcDataReader dbReader = dbCommand.ExecuteReader())
            {
                var fCount = dbReader.FieldCount;
                Console.WriteLine($"fCount = {fCount}");
                // 输出表头
                var columns = new string[fCount];
                for (var i = 0; i < fCount; i++)
                {
                    var fName = dbReader.GetName(i);
                    if (fName.Contains('.'))
                    {
                        fName = fName.Substring(fName.LastIndexOf('.') + 1);
                    }
                    columns[i] = fName;
                }
                // 输出内容
                var table = new ConsoleTable(columns);
                while (dbReader.Read())
                {
                    var row = new object[fCount];
                    for (var i = 0; i < fCount; i++)
                    {
                        if (dbReader.IsDBNull(i))
                        {
                            row[i] = null;
                            continue;
                        }
                        row[i] = dbReader.GetValue(i);
                    }
                    table.AddRow(row);
                }
                table.Write();
                Console.WriteLine();
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.ToString());
    }
}

/// <summary>执行非查询 SQL 语句（如 INSERT 等，树模型 INSERT 会自动创建）</summary>
void Execute(OdbcConnection dbConnection, string command)
{
    try
    {
        using (OdbcCommand dbCommand = dbConnection.CreateCommand())
        {
            try
            {
                dbCommand.CommandText = command;
                Console.WriteLine($"Execute command: {command}");
                dbCommand.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                Console.WriteLine($"CommandText error: {ex.Message}");
            }
        }
    }
    catch (OdbcException ex)
    {
        Console.WriteLine($"数据库错误：{ex.Message}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"发生未知错误：{ex.Message}");
    }
}

var dsn = "Apache IoTDB DSN";
var user = "root";
var password = "root";
var server = "127.0.0.1";
var connectionString = $"DSN={dsn};Server={server};UID={user};PWD={password};loglevel=4;istablemodel=0";

using (OdbcConnection dbConnection = new OdbcConnection(connectionString))
{
    Console.WriteLine($"Start");
    try
    {
        dbConnection.Open();
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Login failed: {ex.Message}");
        Console.WriteLine($"Stack Trace: {ex.StackTrace}");
        dbConnection.Dispose();
        return;
    }
    string[] insertStatements = new string[]
    {
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689600000, true, 100, 10000000000, 36.5, 128.689, '设备运行状态正常', '设备A-机房1', 1735689600000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689660000, false, 101, 10000000001, 36.6, 128.789, '设备运行状态正常', '设备A-机房1', 1735689660000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689720000, true, 102, 10000000002, 36.7, 128.889, '设备运行状态正常', '设备A-机房1', 1735689720000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689780000, false, 103, 10000000003, 36.8, 128.989, '设备温度偏高告警', '设备A-机房1', 1735689780000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689840000, true, 104, 10000000004, 36.9, 129.089, '设备状态恢复正常', '设备A-机房1', 1735689840000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689900000, false, 105, 10000000005, 37.0, 129.189, '设备运行状态正常', '设备B-机房2', 1735689900000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689960000, true, 106, 10000000006, 37.1, 129.289, '设备运行状态正常', '设备B-机房2', 1735689960000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690020000, false, 107, 10000000007, 37.2, 129.389, '设备湿度偏低告警', '设备B-机房2', 1735690020000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690080000, true, 108, 10000000008, 37.3, 129.489, '设备状态恢复正常', '设备B-机房2', 1735690080000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690140000, false, 109, 10000000009, 37.4, 129.589, '设备运行状态正常', '设备C-机房3', 1735690140000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690200000, true, 110, 10000000010, 37.5, 129.689, '设备运行状态正常', '设备C-机房3', 1735690200000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690260000, false, 111, 10000000011, 37.6, 129.789, '设备电压不稳告警', '设备C-机房3', 1735690260000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690320000, true, 112, 10000000012, 37.7, 129.889, '设备状态恢复正常', '设备C-机房3', 1735690320000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690380000, false, 113, 10000000013, 37.8, 129.989, '设备运行状态正常', '设备D-机房4', 1735690380000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690440000, true, 114, 10000000014, 37.9, 130.089, '设备运行状态正常', '设备D-机房4', 1735690440000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690500000, false, 115, 10000000015, 38.0, 130.189, '设备运行状态正常', '设备D-机房4', 1735690500000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690560000, true, 116, 10000000016, 38.1, 130.289, '设备信号中断告警', '设备D-机房4', 1735690560000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690620000, false, 117, 10000000017, 38.2, 130.389, '设备运行状态正常', '设备E-机房5', 1735690620000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690680000, true, 118, 10000000018, 38.3, 130.489, '设备运行状态正常', '设备E-机房5', 1735690680000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690740000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690790000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')"
    };
    foreach (var insert in insertStatements)
    {
        Execute(dbConnection, insert);
    }
    Console.WriteLine($"[DEBUG] Inserted {insertStatements.Length} rows. Begin to query.");

    Query(dbConnection); // 执行查询并输出结果
}
```

### 4.2 Python 示例

1. 通过Python访问odbc，需安装pyodbc包

```Plain
pip install pyodbc
```

2. 完整代码

```Python
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Apache IoTDB ODBC Python 示例 - 树模型（Tree Model）
使用 pyodbc 连接 IoTDB ODBC 驱动，通过 istablemodel=0 使用树模型。
功能参考 examples/BasicTest/TreeTest/TreeTest.cs 和 examples/cpp-example/TreeTest.cpp。
"""

import pyodbc

def execute(conn: pyodbc.Connection, command: str) -> None:
    """执行非查询 SQL 语句（如 INSERT 等，树模型 INSERT 会自动创建）"""
    try:
        with conn.cursor() as cursor:
            cursor.execute(command)
            cmd_upper = command.strip().upper()
            if cmd_upper.startswith(("INSERT", "UPDATE", "DELETE")):
                conn.commit()
            print(f"Execute command: {command}")
    except pyodbc.Error as ex:
        print(f"CommandText error: {ex}")

def query(conn: pyodbc.Connection, sql: str) -> None:
    """执行 SELECT 查询并以表格形式输出 root.full.fulldevice 的结果"""
    try:
        with conn.cursor() as cursor:
            cursor.execute(sql)
            col_count = len(cursor.description)
            print(f"fCount = {col_count}")

            if col_count <= 0:
                return

            columns = []
            for i in range(col_count):
                col_name = cursor.description[i][0] or f"Column{i}"
                if "." in str(col_name):
                    col_name = str(col_name).split(".")[-1]
                columns.append(str(col_name))

            rows = cursor.fetchall()

            col_widths = [max(len(str(col)), 4) for col in columns]
            for row in rows:
                for j, val in enumerate(row):
                    if j < len(col_widths):
                        col_widths[j] = max(col_widths[j], len(str(val) if val is not None else "NULL"))

            header = " | ".join(str(c).ljust(col_widths[i]) for i, c in enumerate(columns))
            print(header)
            print("-" * len(header))

            for row in rows:
                values = []
                for i, val in enumerate(row):
                    if val is None:
                        cell = "NULL"
                    else:
                        cell = str(val)
                    values.append(cell.ljust(col_widths[i]) if i < len(col_widths) else cell)
                print(" | ".join(values))

            print()

    except pyodbc.Error as ex:
        print(f"Query error: {ex}")

def main() -> None:
    dsn = "Apache IoTDB DSN"
    user = "root"
    password = "root"
    server = "127.0.0.1"
    connection_string = (
        f"DSN={dsn};Server={server};UID={user};PWD={password};"
        f"loglevel=4;istablemodel=0"
    )

    print("Start")

    try:
        conn = pyodbc.connect(connection_string)
    except pyodbc.Error as ex:
        print(f"Login failed: {ex}")
        return

    try:
        driver_name = conn.getinfo(6)  # SQL_DRIVER_NAME
        print(f"Successfully opened connection. driver = {driver_name}")
    except Exception:
        print("Successfully opened connection.")

    try:
        insert_statements = [
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689600001, true, 100, 10000000000, 36.5, 128.689, '设备运行状态正常', '设备A-机房1', 1735689600000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689660000, false, 101, 10000000001, 36.6, 128.789, '设备运行状态正常', '设备A-机房1', 1735689660000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689720000, true, 102, 10000000002, 36.7, 128.889, '设备运行状态正常', '设备A-机房1', 1735689720000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689780000, false, 103, 10000000003, 36.8, 128.989, '设备温度偏高告警', '设备A-机房1', 1735689780000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689840000, true, 104, 10000000004, 36.9, 129.089, '设备状态恢复正常', '设备A-机房1', 1735689840000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689900000, false, 105, 10000000005, 37.0, 129.189, '设备运行状态正常', '设备B-机房2', 1735689900000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689960000, true, 106, 10000000006, 37.1, 129.289, '设备运行状态正常', '设备B-机房2', 1735689960000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690020000, false, 107, 10000000007, 37.2, 129.389, '设备湿度偏低告警', '设备B-机房2', 1735690020000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690080000, true, 108, 10000000008, 37.3, 129.489, '设备状态恢复正常', '设备B-机房2', 1735690080000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690140000, false, 109, 10000000009, 37.4, 129.589, '设备运行状态正常', '设备C-机房3', 1735690140000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690200000, true, 110, 10000000010, 37.5, 129.689, '设备运行状态正常', '设备C-机房3', 1735690200000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690260000, false, 111, 10000000011, 37.6, 129.789, '设备电压不稳告警', '设备C-机房3', 1735690260000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690320000, true, 112, 10000000012, 37.7, 129.889, '设备状态恢复正常', '设备C-机房3', 1735690320000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690380000, false, 113, 10000000013, 37.8, 129.989, '设备运行状态正常', '设备D-机房4', 1735690380000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690440000, true, 114, 10000000014, 37.9, 130.089, '设备运行状态正常', '设备D-机房4', 1735690440000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690500000, false, 115, 10000000015, 38.0, 130.189, '设备运行状态正常', '设备D-机房4', 1735690500000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690560000, true, 116, 10000000016, 38.1, 130.289, '设备信号中断告警', '设备D-机房4', 1735690560000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690620000, false, 117, 10000000017, 38.2, 130.389, '设备运行状态正常', '设备E-机房5', 1735690620000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690680000, true, 118, 10000000018, 38.3, 130.489, '设备运行状态正常', '设备E-机房5', 1735690680000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690740000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690790000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')",
        ]
        for insert_sql in insert_statements:
            execute(conn, insert_sql)
        print(f"[DEBUG] Inserted {len(insert_statements)} rows. Begin to query.")

        query_sql = "SELECT * FROM root.full.fulldevice WHERE time >= 1735689600000 AND time <= 1735690790000"
        query(conn, query_sql)
        print("Query ok")
    finally:
        conn.close()

if __name__ == "__main__":
    main()
```

### 4.3 C++ 示例

```C++
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

#include <sql.h>
#include <sqlext.h>
#include <iostream>
#include <string>
#include <vector>
#include <chrono>
#include <ctime>

#ifndef SQL_DIAG_COLUMN_SIZE
#define SQL_DIAG_COLUMN_SIZE  33L
#endif

void CheckOdbcError(SQLRETURN retCode, SQLSMALLINT handleType, SQLHANDLE handle, const char* functionName) {
    if (retCode == SQL_SUCCESS || retCode == SQL_SUCCESS_WITH_INFO) {
        return;
    }

    SQLCHAR sqlState[6];
    SQLCHAR message[SQL_MAX_MESSAGE_LENGTH];
    SQLINTEGER nativeError;
    SQLSMALLINT textLength;
    SQLRETURN errRet;
    errRet = SQLGetDiagRec(handleType, handle, 1, sqlState, &nativeError, message, sizeof(message), &textLength);

    std::cerr << "ODBC Error in " << functionName << ":\n";
    std::cerr << "  SQL State: " << sqlState << "\n";
    std::cerr << "  Native Error: " << nativeError << "\n";
    std::cerr << "  Message: " << message << "\n";
    std::cerr << "  SQLGetDiagRec Return: " << errRet << "\n";

    if (retCode == SQL_ERROR || retCode == SQL_INVALID_HANDLE) {
        exit(1);
    }
}

void PrintSimpleTable(const std::vector<std::string>& headers, 
                     const std::vector<std::vector<std::string>>& rows) {
    for (size_t i = 0; i < headers.size(); i++) {
        std::cout << headers[i];
        if (i < headers.size() - 1) std::cout << "\t";
    }
    std::cout << std::endl;
    
    for (size_t i = 0; i < headers.size(); i++) {
        std::cout << "----------------";
        if (i < headers.size() - 1) std::cout << "\t";
    }
    std::cout << std::endl;
    
    for (const auto& row : rows) {
        for (size_t i = 0; i < row.size(); i++) {
            std::cout << row[i];
            if (i < row.size() - 1) std::cout << "\t";
        }
        std::cout << std::endl;
    }
    std::cout << std::endl;
}

/// 执行 SELECT 查询并以表格形式输出 root.full.fulldevice 的结果
void Query(SQLHDBC hDbc) {
    SQLHSTMT hStmt = SQL_NULL_HSTMT;
    SQLRETURN ret = SQL_SUCCESS;
    
    try {
        ret = SQLAllocHandle(SQL_HANDLE_STMT, hDbc, &hStmt);
        if (!SQL_SUCCEEDED(ret)) {
            CheckOdbcError(ret, SQL_HANDLE_DBC, hDbc, "SQLAllocHandle(SQL_HANDLE_STMT)");
            return;
        }
        
        const std::string sqlQuery = "SELECT * FROM root.full.fulldevice WHERE time >= 1735689600000 AND time <= 1735690790000";
        std::cout << "Execute query: " << sqlQuery << std::endl;

        ret = SQLExecDirect(hStmt, reinterpret_cast<SQLCHAR*>(const_cast<char*>(sqlQuery.c_str())), SQL_NTS);
        if (!SQL_SUCCEEDED(ret)) {
            if (ret != SQL_NO_DATA) {
                CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLExecDirect(SELECT)");
            }
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
            return;
        }
        
        SQLSMALLINT colCount = 0;
        ret = SQLNumResultCols(hStmt, &colCount);
        if (!SQL_SUCCEEDED(ret)) {
            CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLNumResultCols");
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
            return;
        }
        
        std::cout << "Column count = " << colCount << std::endl;
        
        if (colCount <= 0) {
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
            return;
        }
        
        std::vector<std::string> columnNames;
        std::vector<SQLSMALLINT> columnTypes(colCount);
        std::vector<SQLULEN> columnSizes(colCount);
        std::vector<SQLSMALLINT> decimalDigits(colCount);
        std::vector<SQLSMALLINT> nullable(colCount);
        
        // Get basic column information
        for (SQLSMALLINT i = 1; i <= colCount; i++) {
            SQLSMALLINT nameLength = 0;
            ret = SQLDescribeCol(hStmt, i, NULL, 0, &nameLength, NULL, NULL, NULL, NULL);
            if (!SQL_SUCCEEDED(ret)) {
                CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLDescribeCol (get length)");
                SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
                return;
            }
            
            std::vector<SQLCHAR> colNameBuffer(nameLength + 1);
            SQLSMALLINT actualNameLength = 0;
            
            ret = SQLDescribeCol(hStmt, i, colNameBuffer.data(), nameLength + 1, 
                                &actualNameLength, NULL, NULL, NULL, NULL);
            if (!SQL_SUCCEEDED(ret)) {
                CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLDescribeCol (get name)");
                SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
                return;
            }
            
            std::string fullName(reinterpret_cast<char*>(colNameBuffer.data()));
            
            size_t pos = fullName.find_last_of('.');
            if (pos != std::string::npos) {
                columnNames.push_back(fullName.substr(pos + 1));
            } else {
                columnNames.push_back(fullName);
            }
            
            ret = SQLDescribeCol(hStmt, i, NULL, 0, NULL, &columnTypes[i-1], 
                                &columnSizes[i-1], &decimalDigits[i-1], &nullable[i-1]);
            if (!SQL_SUCCEEDED(ret)) {
                CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLDescribeCol (get type info)");
                SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
                return;
            }
        }
        
        std::vector<std::vector<std::string>> tableRows;
        
        int rowCount = 0;
        // Get data front every row
        while (true) {
            ret = SQLFetch(hStmt);
            if (ret == SQL_NO_DATA) {
                break;  
            }

            if (!SQL_SUCCEEDED(ret)) {
                CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLFetch");
                break;
            }
            
            std::vector<std::string> row;
            
            for (SQLSMALLINT i = 1; i <= colCount; i++) {
                SQLLEN indicator = 0;
                std::string valueStr;
                
                SQLSMALLINT cType;
                size_t bufferSize;
                bool isCharacterType = false;
                const int maxBufferSize = 32768;
                
                switch (columnTypes[i-1]) {
                    case SQL_CHAR:
                    case SQL_VARCHAR:
                    case SQL_LONGVARCHAR:
                    case SQL_WCHAR:
                    case SQL_WVARCHAR:
                    case SQL_WLONGVARCHAR:
                        cType = SQL_C_CHAR;
                        if (columnSizes[i - 1] > 0) {
                            bufferSize = min(maxBufferSize, static_cast<size_t>(columnSizes[i-1]) * 4 + 1);
                        } else {
                            bufferSize = maxBufferSize;
                        }
                        isCharacterType = true;
                        break;
                        
                    case SQL_DECIMAL:
                    case SQL_NUMERIC:
                        cType = SQL_C_CHAR;
                        if (columnSizes[i - 1] > 0) {
                            bufferSize = min(maxBufferSize, static_cast<size_t>(columnSizes[i-1]) * 4 + 1);
                        } else {
                            bufferSize = maxBufferSize;
                        }
                        isCharacterType = true;
                        break;
                        
                    case SQL_INTEGER:
                    case SQL_SMALLINT:
                    case SQL_TINYINT:
                    case SQL_BIGINT:
                        cType = SQL_C_SBIGINT;  
                        bufferSize = sizeof(SQLBIGINT);
                        break;
                        
                    case SQL_REAL:
                    case SQL_FLOAT:
                    case SQL_DOUBLE:
                        cType = SQL_C_DOUBLE;
                        bufferSize = sizeof(double);
                        break;
                        
                    case SQL_BIT:
                        cType = SQL_C_BIT;
                        bufferSize = sizeof(SQLCHAR);
                        break;
                        
                    case SQL_DATE:
                    case SQL_TYPE_DATE:
                        cType = SQL_C_DATE;
                        bufferSize = sizeof(SQL_DATE_STRUCT);
                        break;
                        
                    case SQL_TIME:
                    case SQL_TYPE_TIME:
                        cType = SQL_C_TIME;
                        bufferSize = sizeof(SQL_TIME_STRUCT);
                        break;
                        
                    case SQL_TIMESTAMP:
                    case SQL_TYPE_TIMESTAMP:
                        cType = SQL_C_TIMESTAMP;
                        bufferSize = sizeof(SQL_TIMESTAMP_STRUCT);
                        break;
                        
                    default:
                        cType = SQL_C_CHAR;
                        bufferSize = 256; 
                        isCharacterType = true;
                        break;
                }
                
                std::vector<BYTE> buffer(bufferSize);

                ret = SQLGetData(hStmt, i, cType, buffer.data(), bufferSize, &indicator);

                if (indicator == SQL_NULL_DATA) {
                    valueStr = "NULL";
                } 
                else if (ret != SQL_SUCCESS) {
                    valueStr = "ERR_CONV";
                }
                else {
                    if (cType == SQL_C_CHAR) {
                        valueStr = reinterpret_cast<char*>(buffer.data());
                    }
                    else if (cType == SQL_C_SBIGINT) {
                        SQLBIGINT intVal = *reinterpret_cast<SQLBIGINT*>(buffer.data());
                        valueStr = std::to_string(intVal);
                    }
                    else if (cType == SQL_C_DOUBLE) {
                        double doubleVal = *reinterpret_cast<double*>(buffer.data());
                        valueStr = std::to_string(doubleVal);
                    }
                    else if (cType == SQL_C_BIT) {
                        valueStr = (*buffer.data() != 0) ? "TRUE" : "FALSE";
                    }
                    else if (cType == SQL_C_DATE) {
                        SQL_DATE_STRUCT* date = reinterpret_cast<SQL_DATE_STRUCT*>(buffer.data());
                        char dateStr[20];
                        snprintf(dateStr, sizeof(dateStr), "%04d-%02d-%02d", 
                                date->year, date->month, date->day);
                        valueStr = dateStr;
                    }
                    else if (cType == SQL_C_TIME) {
                        SQL_TIME_STRUCT* time = reinterpret_cast<SQL_TIME_STRUCT*>(buffer.data());
                        char timeStr[15];
                        snprintf(timeStr, sizeof(timeStr), "%02d:%02d:%02d", 
                                time->hour, time->minute, time->second);
                        valueStr = timeStr;
                    }
                    else if (cType == SQL_C_TIMESTAMP) {
                        SQL_TIMESTAMP_STRUCT* ts = reinterpret_cast<SQL_TIMESTAMP_STRUCT*>(buffer.data());
                        char tsStr[30];
                        snprintf(tsStr, sizeof(tsStr), "%04d-%02d-%02d %02d:%02d:%02d.%06d", 
                                ts->year, ts->month, ts->day,
                                ts->hour, ts->minute, ts->second,
                                ts->fraction / 1000); 
                        valueStr = tsStr;
                    }
                    else {
                        valueStr = "UNKNOWN_TYPE";
                    }
                    
                    if (isCharacterType && ret == SQL_SUCCESS_WITH_INFO) {
                        SQLLEN actualSize = 0;
                        SQLGetDiagField(SQL_HANDLE_STMT, hStmt, 0, SQL_DIAG_COLUMN_SIZE, 
                                       &actualSize, SQL_IS_INTEGER, NULL);
                        
                        if (indicator > 0 && static_cast<size_t>(indicator) > bufferSize - 1) {
                            valueStr += "...";  
                        }
                    }
                    
                }
                
                row.push_back(valueStr);
            }
            
            tableRows.push_back(row);
        }
        
        if (!tableRows.empty()) {
            PrintSimpleTable(columnNames, tableRows);
        }
        
        SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
    }
    catch (const std::exception& ex) {
        std::cerr << "Exception: " << ex.what() << std::endl;
        if (hStmt != SQL_NULL_HSTMT) {
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
        }
        throw;
    }
    catch (...) {
        std::cerr << "Unknown exception occurred" << std::endl;
        if (hStmt != SQL_NULL_HSTMT) {
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
        }
        throw;
    }
}

/// 执行非查询 SQL 语句（如 INSERT 等，树模型 INSERT 会自动创建）
void Execute(SQLHDBC hDbc, const std::string& command) {
    SQLHSTMT hStmt = SQL_NULL_HSTMT;
    SQLRETURN ret;
    
    try {
        ret = SQLAllocHandle(SQL_HANDLE_STMT, hDbc, &hStmt);
        CheckOdbcError(ret, SQL_HANDLE_DBC, hDbc, "SQLAllocHandle(SQL_HANDLE_STMT)");
        
        ret = SQLExecDirect(hStmt, (SQLCHAR*)command.c_str(), SQL_NTS);
        if (ret != SQL_SUCCESS && ret != SQL_SUCCESS_WITH_INFO) {
            CheckOdbcError(ret, SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
        }
        
        SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
    }
    catch (...) {
        if (hStmt != SQL_NULL_HSTMT) {
            SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
        }
        throw;
    }
}

int main() {
    SQLHENV hEnv = SQL_NULL_HENV;
    SQLHDBC hDbc = SQL_NULL_HDBC;
    SQLRETURN ret;
    
    try {
        std::cout << "Start" << std::endl;
        
        ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv);
        CheckOdbcError(ret, SQL_HANDLE_ENV, hEnv, "SQLAllocHandle(SQL_HANDLE_ENV)");
        
        ret = SQLSetEnvAttr(hEnv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0);
        CheckOdbcError(ret, SQL_HANDLE_ENV, hEnv, "SQLSetEnvAttr");
        
        ret = SQLAllocHandle(SQL_HANDLE_DBC, hEnv, &hDbc);
        CheckOdbcError(ret, SQL_HANDLE_ENV, hEnv, "SQLAllocHandle(SQL_HANDLE_DBC)");
        
        std::string dsn = "Apache IoTDB DSN";
        std::string user = "root";
        std::string password = "root";
        std::string server = "127.0.0.1";
        
        std::string connectionString = "DSN=" + dsn + ";Server=" + server + 
                                     ";UID=" + user + ";PWD=" + password + 
                                     ";loglevel=4;istablemodel=0";
        std::cout << "Using connection string: " << connectionString << std::endl;
        
        SQLCHAR outConnStr[1024];
        SQLSMALLINT outConnStrLen;
        
        ret = SQLDriverConnect(hDbc, NULL, 
                              (SQLCHAR*)connectionString.c_str(), SQL_NTS,
                              outConnStr, sizeof(outConnStr),
                              &outConnStrLen, SQL_DRIVER_COMPLETE);
        
        if (ret != SQL_SUCCESS && ret != SQL_SUCCESS_WITH_INFO) {
            std::cerr << "Login failed" << std::endl;
            CheckOdbcError(ret, SQL_HANDLE_DBC, hDbc, "SQLDriverConnect");
            return 1;
        }
        
        SQLCHAR driverName[256];
        SQLSMALLINT nameLength;
        ret = SQLGetInfo(hDbc, SQL_DRIVER_NAME, driverName, sizeof(driverName), &nameLength);
        CheckOdbcError(ret, SQL_HANDLE_DBC, hDbc, "SQLGetInfo");
        
        std::cout << "Successfully opened connection. database name = " << driverName << std::endl;
        
        const char* insertStatements[] = {
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689600000, true, 100, 10000000000, 36.5, 128.689, '设备运行状态正常', '设备A-机房1', 1735689600000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689660000, false, 101, 10000000001, 36.6, 128.789, '设备运行状态正常', '设备A-机房1', 1735689660000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689720000, true, 102, 10000000002, 36.7, 128.889, '设备运行状态正常', '设备A-机房1', 1735689720000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689780000, false, 103, 10000000003, 36.8, 128.989, '设备温度偏高告警', '设备A-机房1', 1735689780000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689840000, true, 104, 10000000004, 36.9, 129.089, '设备状态恢复正常', '设备A-机房1', 1735689840000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689900000, false, 105, 10000000005, 37.0, 129.189, '设备运行状态正常', '设备B-机房2', 1735689900000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735689960000, true, 106, 10000000006, 37.1, 129.289, '设备运行状态正常', '设备B-机房2', 1735689960000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690020000, false, 107, 10000000007, 37.2, 129.389, '设备湿度偏低告警', '设备B-机房2', 1735690020000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690080000, true, 108, 10000000008, 37.3, 129.489, '设备状态恢复正常', '设备B-机房2', 1735690080000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690140000, false, 109, 10000000009, 37.4, 129.589, '设备运行状态正常', '设备C-机房3', 1735690140000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690200000, true, 110, 10000000010, 37.5, 129.689, '设备运行状态正常', '设备C-机房3', 1735690200000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690260000, false, 111, 10000000011, 37.6, 129.789, '设备电压不稳告警', '设备C-机房3', 1735690260000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690320000, true, 112, 10000000012, 37.7, 129.889, '设备状态恢复正常', '设备C-机房3', 1735690320000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690380000, false, 113, 10000000013, 37.8, 129.989, '设备运行状态正常', '设备D-机房4', 1735690380000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690440000, true, 114, 10000000014, 37.9, 130.089, '设备运行状态正常', '设备D-机房4', 1735690440000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690500000, false, 115, 10000000015, 38.0, 130.189, '设备运行状态正常', '设备D-机房4', 1735690500000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690560000, true, 116, 10000000016, 38.1, 130.289, '设备信号中断告警', '设备D-机房4', 1735690560000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690620000, false, 117, 10000000017, 38.2, 130.389, '设备运行状态正常', '设备E-机房5', 1735690620000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690680000, true, 118, 10000000018, 38.3, 130.489, '设备运行状态正常', '设备E-机房5', 1735690680000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690740000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')",
            "INSERT INTO root.full.fulldevice(timestamp, bool_col, int32_col, int64_col, float_col, double_col, text_col, string_col, timestamp_col, date_col) VALUES (1735690790000, false, 119, 10000000019, 38.4, 130.589, '设备运行状态正常', '设备E-机房5', 1735690740000, '2026-01-04')"
        };
        for (const char* sql : insertStatements) {
            Execute(hDbc, sql);
        }
        std::cout << "[DEBUG] Inserted 20 rows. Begin to query." << std::endl;
        Query(hDbc);
        std::cout << "Query ok" << std::endl;

        SQLDisconnect(hDbc);
        SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        
        return 0;
    }
    catch (...) {
        if (hDbc != SQL_NULL_HDBC) {
            SQLDisconnect(hDbc);
            SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
        }
        if (hEnv != SQL_NULL_HENV) {
            SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        }
        
        std::cerr << "Unexpected error!" << std::endl;
        return 1;
    }
}
```

### 4.4 PowerBI 示例

1. 打开 PowerBI Desktop，创建新项目；
2. 点击「主页」→「获取数据」→「更多...」→「ODBC」→ 点击「连接」按钮；
3. 数据源选择：在弹出窗口中选择「数据源名称 (DSN)」，下拉选择 `Apache IoTDB DSN`；
4. 高级配置：

* 点击「高级选项」，在「连接字符串」输入框填写配置（样例）：

```Plain
server=127.0.0.1;port=6667;isTableModel=false;loglevel=4
```

* 说明：

  * `dsn` 项可选，填写 / 不填写均不影响连接；
  * `loglevel` 分为 0-4 等级：0 级（ERROR）日志最少，4 级（TRACE）日志最详细，按需设置；
  * `server`/`dsn`/`loglevel` 大小写不敏感（如可写为 `Server`）；
  * 如果在DSN中配置了相关信息，则可以不填写任何配置信息，驱动管理器会自动使用在DSN中填入的配置信息。

5. 身份验证：输入用户名（默认 `root`）和密码（默认 `root`），点击「连接」；
6. 数据加载：点击「加载」即可查看数据。

### 4.5 Excel 示例

1. 打开 Excel，创建空白工作簿；
2. 点击「数据」选项卡 →「自其他来源」→「来自数据连接向导」；
3. 数据源选择：选择「ODBC DSN」→ 下一步 → 选择 `Apache IoTDB DSN` → 下一步；
4. 连接配置：
* 连接字符串、用户名、密码的输入流程与 PowerBI 完全一致，连接字符串格式参考：

```Plain
server=127.0.0.1;port=6667;isTableModel=false;loglevel=4
```

* 如果在DSN中配置了相关信息，则可以不填写任何配置信息，驱动管理器会自动使用在DSN中填入的配置信息。
5. 保存连接：自定义设置数据连接文件名、连接描述等信息，点击「完成」；
6. 导入数据：选择数据导入到工作表的位置（如「现有工作表」的 A1 单元格），点击「确定」，完成数据加载。