Tablestore:SQL query

Enter the SQL mode

Run the sql command to enter the SQL mode.

Query mapping tables

Query the mapping tables that are created for tables in an instance.

Run the SHOW TABLES; command to query the mapping tables that are created for tables in an instance.

+----------------------+
| Tables_in_myinstance |
+----------------------+
| mytable              |
+----------------------+
| mytstable            |
+----------------------+
| mytstable::meta      |
+----------------------+

In the preceding command output, mytable is a mapping table that is created for a data table, mytstable is a mapping table that is created for a time series data table, and mytstable::meta is a mapping table that is created for a time series metadata table.

Query information about a mapping table

Query information about a mapping table.

• Command syntax

  DESCRIBE table_name;

• Examples

  The following sample code shows how to query the information about the mapping table named mytable:

  DESCRIBE mytable;

  The following result is returned:

  +-------+---------------+------+-----+-------+
  | Field | Type          | Null | Key | Extra |
  +-------+---------------+------+-----+-------+
  | uid   | varchar(1024) | NO   | PRI |       |
  +-------+---------------+------+-----+-------+
  | pid   | bigint(20)    | NO   | PRI |       |
  +-------+---------------+------+-----+-------+
  | b     | double        | YES  |     |       |
  +-------+---------------+------+-----+-------+
  | c     | tinyint(1)    | YES  |     |       |
  +-------+---------------+------+-----+-------+
  | d     | mediumtext    | YES  |     |       |
  +-------+---------------+------+-----+-------+

Query the data in a table

Query the data in a table by executing the SELECT statement.

SELECT * FROM mytstable limit 10;

Exit the SQL mode

Run the exit; command to exit the SQL mode.

FAQ

• How do I select a query method when I use SQL to query data?

• How do I troubleshoot common errors of SQL queries?

• What do I do if the "The sql scanned rows of main table exceeds the quota, main table rows quota is 100000" error message appears when I use SQL to query data?

References

• You can use the SQL query feature by using the Tablestore console, Tablestore SDKs, JDBC, and JDBC driver for Go.

  • Use the SQL query feature in the Tablestore console

  • Use Tablestore SDKs to use the SQL query feature

  • Use JDBC

    • Use JDBC to access Tablestore

    • Use Hibernate to query data by executing SQL statements

    • Use MyBatis to query data by executing SQL statements

  • Use the Tablestore driver for Go to query data by executing SQL statements

• If you want to accelerate data queries and computing by executing SQL statements, you can create a secondary index or a search index. For more information, see Index selection policy and Computing pushdown.

• You can also use computing engines, such as MaxCompute, Spark, Hive, HadoopMR, Function Compute, Flink, and PrestoDB, to compute and analyze data in tables. For more information, see Overview.