DESCRIBE Statements

    Java

    DESCRIBE statements can be executed with the method of the TableEnvironment. The executeSql() method returns the schema of given table for a successful DESCRIBE operation, otherwise will throw an exception.

    The following examples show how to run a DESCRIBE statement in TableEnvironment.

    Scala

    DESCRIBE statements can be executed with the executeSql() method of the TableEnvironment. The executeSql() method returns the schema of given table for a successful DESCRIBE operation, otherwise will throw an exception.

    The following examples show how to run a DESCRIBE statement in TableEnvironment.

    DESCRIBE statements can be executed with the execute_sql() method of the TableEnvironment. The execute_sql() method returns the schema of given table for a successful DESCRIBE operation, otherwise will throw an exception.

    The following examples show how to run a DESCRIBE statement in TableEnvironment.

    SQL CLI

    DESCRIBE statements can be executed in SQL CLI.

    The following examples show how to run a DESCRIBE statement in SQL CLI.

    Java

    1. val tableEnv = TableEnvironment.create(...)
    3. // register a table named "Orders"
    4.  tableEnv.executeSql(
    5.         "CREATE TABLE Orders (" +
    6.         " `user` BIGINT NOT NULl," +
    7.         " product VARCHAR(32)," +
    8.         " amount INT," +
    9.         " ts TIMESTAMP(3)," +
    10.         " ptime AS PROCTIME()," +
    11.         " PRIMARY KEY(`user`) NOT ENFORCED," +
    12.         " WATERMARK FOR ts AS ts - INTERVAL '1' SECONDS" +
    13.         ") with (...)")
    15. // print the schema
    18. // print the schema
    19. tableEnv.executeSql("DESC Orders").print()

    Python

    1. table_env = TableEnvironment.create(...)
    3. table_env.execute_sql( \
    4.         "CREATE TABLE Orders (" 
    5.         " `user` BIGINT NOT NULl," 
    6.         " product VARCHAR(32),"
    7.         " amount INT,"
    8.         " ts TIMESTAMP(3),"
    9.         " ptime AS PROCTIME(),"
    10.         " PRIMARY KEY(`user`) NOT ENFORCED,"
    11.         " WATERMARK FOR ts AS ts - INTERVAL '1' SECONDS"
    12.         ") with (...)");
    14. # print the schema
    15. table_env.execute_sql("DESCRIBE Orders").print()
    17. # print the schema
    18. table_env.execute_sql("DESC Orders").print()

    SQL CLI

    The result of the above example is:

    Java

    2. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    3. |    name |                             type |  null |       key | computed column |                  watermark |
    4. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    6. | product |                      VARCHAR(32) |  true |           |                 |                            |
    7. |  amount |                              INT |  true |           |                 |                            |
    8. |   ptime | TIMESTAMP(3) NOT NULL *PROCTIME* | false |           |      PROCTIME() |                            |
    9. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    10. 5 rows in set

    Scala

    2. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    3. |    name |                             type |  null |       key | computed column |                  watermark |
    4. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    5. |    user |                           BIGINT | false | PRI(user) |                 |                            |
    6. | product |                      VARCHAR(32) |  true |           |                 |                            |
    7. |  amount |                              INT |  true |           |                 |                            |
    8. |      ts |           TIMESTAMP(3) *ROWTIME* |  true |           |                 | `ts` - INTERVAL '1' SECOND |
    9. |   ptime | TIMESTAMP(3) NOT NULL *PROCTIME* | false |           |      PROCTIME() |                            |
    10. +---------+----------------------------------+-------+-----------+-----------------+----------------------------+
    11. 5 rows in set

    Python

    2. root
    3.  |-- user: BIGINT NOT NULL
    4.  |-- product: VARCHAR(32)
    5.  |-- amount: INT
    6.  |-- ts: TIMESTAMP(3) *ROWTIME*
    7.  |-- ptime: TIMESTAMP(3) NOT NULL *PROCTIME* AS PROCTIME()
    8.  |-- WATERMARK FOR ts AS `ts` - INTERVAL '1' SECOND
    9.  |-- CONSTRAINT PK_3599338 PRIMARY KEY (user)

    Syntax