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# ODBC

With IoTDB JDBC, IoTDB can be accessed using the ODBC-JDBC bridge.

## Dependencies

- IoTDB-JDBC's jar-with-dependency package
- ODBC-JDBC bridge (e.g. ZappySys JDBC Bridge)

## Deployment

### Preparing JDBC package

Download the source code of IoTDB, and execute the following command in root directory:

```shell
mvn clean package -pl iotdb-client/jdbc -am -DskipTests -P get-jar-with-dependencies
```

Then, you can see the output `iotdb-jdbc-1.3.2-SNAPSHOT-jar-with-dependencies.jar` under `iotdb-client/jdbc/target` directory.

### Preparing ODBC-JDBC Bridge

_Note: Here we only provide one kind of ODBC-JDBC bridge as the instance. Readers can use other ODBC-JDBC bridges to access IoTDB with the IOTDB-JDBC._

1. **Download Zappy-Sys ODBC-JDBC Bridge**:
   Enter the <https://zappysys.com/products/odbc-powerpack/odbc-jdbc-bridge-driver/> website, and click "download".

   ![ZappySys_website.jpg](/img/ZappySys_website.jpg)

2. **Prepare IoTDB**: Set up IoTDB cluster, and write a row of data arbitrarily.

   ```sql
   IoTDB > insert into root.ln.wf02.wt02(timestamp,status) values(1,true)
   ```

3. **Deploy and Test the Bridge**:

   1. Open ODBC Data Sources(32/64 bit), depending on the bits of Windows. One possible position is `C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Administrative Tools`.

      ![ODBC_ADD_EN.jpg](/img/ODBC_ADD_EN.jpg)

   2. Click on "add" and select ZappySys JDBC Bridge.

      ![ODBC_CREATE_EN.jpg](/img/ODBC_CREATE_EN.jpg)

   3. Fill in the following settings:

      | Property            | Content                                                   | Example                                                                                                            |
      | ------------------- | --------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
      | Connection String   | jdbc:iotdb://\<The IP of IoTDB>:\<The rpc port of IoTDB>/ | jdbc:iotdb://127.0.0.1:6667/                                                                                       |
      | Driver Class        | org.apache.iotdb.jdbc.IoTDBDriver                         | org.apache.iotdb.jdbc.IoTDBDriver                                                                                  |
      | JDBC driver file(s) | The path of IoTDB JDBC jar-with-dependencies              | C:\Users\13361\Documents\GitHub\iotdb\iotdb-client\jdbc\target\iotdb-jdbc-1.3.2-SNAPSHOT-jar-with-dependencies.jar |
      | User name           | IoTDB's user name                                         | root                                                                                                               |
      | User password       | IoTDB's password                                          | root                                                                                                               |

      ![ODBC_CONNECTION.png](/img/ODBC_CONNECTION.png)

   4. Click on "Test Connection" button, and a "Test Connection: SUCCESSFUL" should appear.

      ![ODBC_CONFIG_EN.jpg](/img/ODBC_CONFIG_EN.jpg)

   5. Click the "Preview" button above, and replace the original query text with `select * from root.**`, then click "Preview Data", and the query result should correctly.

      ![ODBC_TEST.jpg](/img/ODBC_TEST.jpg)

4. **Operate IoTDB's data with ODBC**: After correct deployment, you can use Microsoft's ODBC library to operate IoTDB's data. Here's an example written in C#:

   ```C#
   using System.Data.Odbc;

   // Get a connection
   var dbConnection = new OdbcConnection("DSN=ZappySys JDBC Bridge");
   dbConnection.Open();

   // Execute the write commands to prepare data
   var dbCommand = dbConnection.CreateCommand();
   dbCommand.CommandText = "insert into root.Keller.Flur.Energieversorgung(time, s1) values(1715670861634, 1)";
   dbCommand.ExecuteNonQuery();
   dbCommand.CommandText = "insert into root.Keller.Flur.Energieversorgung(time, s2) values(1715670861634, true)";
   dbCommand.ExecuteNonQuery();
   dbCommand.CommandText = "insert into root.Keller.Flur.Energieversorgung(time, s3) values(1715670861634, 3.1)";
   dbCommand.ExecuteNonQuery();

   // Execute the read command
   dbCommand.CommandText = "SELECT * FROM root.Keller.Flur.Energieversorgung";
   var dbReader = dbCommand.ExecuteReader();

   // Write the output header
   var fCount = dbReader.FieldCount;
   Console.Write(":");
   for(var i = 0; i < fCount; i++)
   {
       var fName = dbReader.GetName(i);
       Console.Write(fName + ":");
   }
   Console.WriteLine();

   // Output the content
   while (dbReader.Read())
   {
       Console.Write(":");
       for(var i = 0; i < fCount; i++)
       {
           var fieldType = dbReader.GetFieldType(i);
           switch (fieldType.Name)
           {
               case "DateTime":
                   var dateTime = dbReader.GetInt64(i);
                   Console.Write(dateTime + ":");
                   break;
               case "Double":
                   if (dbReader.IsDBNull(i))
                   {
                       Console.Write("null:");
                   }
                   else
                   {
                       var fValue = dbReader.GetDouble(i);
                       Console.Write(fValue + ":");
                   }
                   break;
               default:
                   Console.Write(fieldType.Name + ":");
                   break;
           }
       }
       Console.WriteLine();
   }

   // Shut down gracefully
   dbReader.Close();
   dbCommand.Dispose();
   dbConnection.Close();
   ```

   This program can write data into IoTDB, and query the data we have just written.