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# MyBatisPlus Generator

## 1. Overview

MyBatis-Plus Generator is a built-in code generation tool of the MyBatis-Plus framework. It automatically generates standardized entity classes, Mapper interfaces, Service layers, and Controller layer code based on the database table structure. It integrates MyBatis-Plus's general CRUD methods (such as `BaseMapper` built-in create, read, update, delete) and condition constructors (`QueryWrapper`), and supports extended annotations like Lombok and Swagger. Through simple configuration, it can quickly build persistent layer code that conforms to enterprise-level specifications, greatly reducing repetitive development work for single-table operations. It is suitable for quickly building background management systems or standardized data service modules.

The following will introduce how to use Mybatis-Plus Generator to connect to IoTDB and generate entity classes, Mapper interfaces, Service layers, and Controller layer code files corresponding to database tables.

## 2. Usage Steps

### 2.1 Version Requirements

- IoTDB: >=2.0.2-SNAPSHOT
- mybatisPlus: >=3.5.10
- iotdb-jdbc:>=2.0.4-SNAPSHOT

### 2.2 Operating Process

#### 2.2.1 IoTDB Environment Setup

1. Download, install, and start the IoTDB service. For details, refer to [QuickStart](../QuickStart/QuickStart.md)
2. Create the database database1 and tables table1 / table2. Relevant SQL statements can refer to [Sample-Data](../Reference/Sample-Data.md)

#### 2.2.2 Create a Maven Project

1. Create a Maven project
2. Add the following dependency configurations to the pom

```XML
<properties>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
        <version>3.5.10</version>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-generator</artifactId>
        <version>3.5.10</version>
    </dependency>
    <dependency>
        <groupId>com.github.jeffreyning</groupId>
        <artifactId>mybatisplus-plus</artifactId>
        <version>1.7.5-RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.apache.velocity</groupId>
        <artifactId>velocity-engine-core</artifactId>
        <version>2.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.iotdb</groupId>
        <artifactId>iotdb-jdbc</artifactId>
        <version>2.0.4-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <version>3.4.3</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
            </exclusion>
            <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>3.4.3</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
            </exclusion>
            <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <version>3.0.0</version>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>3.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.36</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <version>3.4.3</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>2.0.13</version>
    </dependency>
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.5.16</version>
    </dependency>
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-core</artifactId>
        <version>1.5.16</version>
    </dependency>
</dependencies>
<build>
    <plugins>
        <plugin>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-maven-plugin</artifactId>
            <version>1.4.2</version>
            <dependencies>
                <dependency>
                    <groupId>org.apache.iotdb</groupId>
                    <artifactId>mybatis-generator-plugin</artifactId>
                    <version>2.0.2-SNAPSHOT</version>
                </dependency>
            </dependencies>
            <configuration>
                <verbose>true</verbose>
                <overwrite>true</overwrite>
                <configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
            </configuration>
        </plugin>
    </plugins>
</build>
```
3. Create an execution file, modify the `url`/`username`/`password` of the target IoTDB, and the target file generation directory `outputDir`/`pathInfo`

```Java
package org.apache.iotdb;

import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.OutputFile;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.DbColumnType;
import org.apache.iotdb.jdbc.IoTDBDataSource;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.sql.Types;
import java.util.Collections;


@SpringBootApplication
@MapperScan("org.apache.iotdb.mapper")
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
        IoTDBDataSource dataSource = new IoTDBDataSource();
        dataSource.setUrl("jdbc:iotdb://127.0.0.1:6667/database1?sql_dialect=table");
        dataSource.setUser("root");
        dataSource.setPassword("root");
        FastAutoGenerator generator = FastAutoGenerator.create(new DataSourceConfig.Builder(dataSource).driverClassName("org.apache.iotdb.jdbc.IoTDBDriver"));
        generator
                .globalConfig(builder -> {
                    builder.author("IoTDB")
                            .enableSwagger()
                            .dateType(DateType.ONLY_DATE)
                            .outputDir("src/main/java");
                })
                .packageConfig(builder -> {
                    builder.parent("org.apache.iotdb")
                            .mapper("mapper")
                            .pathInfo(Collections.singletonMap(OutputFile.xml, "src/main/java/org/apache/iotdb/xml"));
                })
                .dataSourceConfig(builder -> {
                    builder.typeConvertHandler((globalConfig, typeRegistry, metaInfo) -> {
                        int typeCode = metaInfo.getJdbcType().TYPE_CODE;
                        switch (typeCode) {
                            case Types.FLOAT:
                                return DbColumnType.FLOAT;
                            default:
                                return typeRegistry.getColumnType(metaInfo);
                        }
                    });
                })
                .strategyConfig(builder -> {
                    builder.addInclude("table1");
                    builder.entityBuilder()
                            .enableLombok()
//                            .addIgnoreColumns("create_time")
                            .enableFileOverride();
                    builder.serviceBuilder()
                            .formatServiceFileName("%sService")
                            .formatServiceImplFileName("%sServiceImpl")
                            .convertServiceFileName((entityName -> entityName + "Service"))
                            .enableFileOverride();
                    builder.controllerBuilder()
                            .enableRestStyle()
                            .enableFileOverride();
                })
                .strategyConfig(builder -> {
                    builder.addInclude("table2");
                    builder.entityBuilder()
                            .enableLombok()
//                            .addIgnoreColumns("create_time")
                            .enableFileOverride();
                    builder.serviceBuilder()
                            .formatServiceFileName("%sService")
                            .formatServiceImplFileName("%sServiceImpl")
                            .convertServiceFileName((entityName -> entityName + "Service"))
                            .enableFileOverride();
                    builder.controllerBuilder()
                            .enableRestStyle()
                            .enableFileOverride();
                })
                .execute();
    }
}
```

#### 2.2.3 Generate Target Files

1. Run Main.java
2. View the log output. The following indicates that the target files are generated

```Java
16:10:08.943 [main] DEBUG com.baomidou.mybatisplus.generator.AutoGenerator -- ==========================File generation completed！！！==========================
```

#### 2.2.4 Generate Target Files

```Plain
org/apache/iotdb/controller/Table1Controller.java
org/apache/iotdb/controller/Table2Controller.java
org/apache/iotdb/entity/Table1.java
org/apache/iotdb/mapper/Table2.xml
org/apache/iotdb/service/Table1Service.java  
org/apache/iotdb/service/Table2Service.java
org/apache/iotdb/service/impl/Table1ServiceImpl.java  
org/apache/iotdb/service/impl/Table2ServiceImpl.java
org/apache/iotdb/xml/Table1Mapper.xml
org/apache/iotdb/xml/Table2Mapper.xml
```
![](/img/MyBatisPlus-Generator.png)

#### 2.2.5 Modify Annotations

Manually adjust the generated code `org/apache/iotdb/entity/Table1.java`, `org/apache/iotdb/entity/Table2.java` to support multi-primary key queries.

```TypeScript
// Add new import
import com.github.jeffreyning.mybatisplus.anno.MppMultiId;

// Add new annotation @MppMultiId
@MppMultiId
// Modify annotation @TableId() -->> @TableField()
@TableField("time")
private Date time;

// Add new annotation @MppMultiId
@MppMultiId
// Modify annotation @TableId() -->> @TableField()
@TableField("region")
private String region;

// Add new annotation @MppMultiId
@MppMultiId
// Modify annotation @TableId() -->> @TableField()
@TableField("plant_id")
private String plantId;

// Add new annotation @MppMultiId
@MppMultiId
// Modify annotation @TableId() -->> @TableField()
@TableField("device_id")
private String deviceId;
```

## 3. Usage Example

For a complete usage example, refer to the source code [examples/mybatisplus-generator](https://github.com/apache/iotdb-extras/tree/master/examples/mybatisplus-generator)