You can execute the DESCRIBE statement to query the information about tables, such as the field names and field types.
Note
For more information about the DESCRIBE statement, see Query information about tables.
Prerequisites
- An OTSClient instance is initialized. For more information, see Initialize an OTSClient instance.
- A mapping table is created. For more information, see Create a mapping table.
Usage notes
Tablestore SDK for .NET V5.0.0 or later supports SQL queries. To perform SQL queries by using Tablestore SDK for .NET, make sure that your SDK version is 5.0.0 or later. We recommend that you use the latest SDK. For more information, see Version history of Tablestore SDK for .NET.
Parameters
Parameter | Description |
query | The SQL statement. Configure the parameter based on the required feature. |
Examples
The following sample code provides an example on how to execute the describe test_table statement to query the information about test_table:
/// <summary>
/// Query information about a table.
/// </summary>
/// <param name="otsClient"></param>
public static void DescribeTable(OTSClient otsClient)
{
SQLQueryRequest sqlQueryRequest = new SQLQueryRequest("describe test_table");
SQLQueryResponse sqlQueryResponse = otsClient.SQLQuery(sqlQueryRequest);
SQLTableMeta sqlTableMeta = sqlQueryResponse.GetSQLResultSet().GetSQLTableMeta();
Console.WriteLine(JsonConvert.SerializeObject(sqlTableMeta.GetSchema()));
ISQLResultSet resultSet = sqlQueryResponse.GetSQLResultSet();
while (resultSet.HasNext())
{
ISQLRow row = resultSet.Next();
Console.WriteLine(row.GetString(0) + " " + row.GetString(1) + " " + row.GetString(2) + " " +
row.GetString(3) + " " + row.GetString(4) + " " + row.GetString(5));
}
}