SHOW WARNINGS

SHOW WARNINGS statement can be used to retrieve the warning produced by the latest query. The error message will be returned along with the query itself:

  1. mysql> SELECT * FROM test1 WHERE MATCH('@@title hello') \G
  2. ERROR 1064 (42000): index test1: syntax error, unexpected TOK_FIELDLIMIT
  3. near '@title hello'
  5. mysql> SELECT * FROM test1 WHERE MATCH('@title -hello') \G
  6. ERROR 1064 (42000): index test1: query is non-computable (single NOT operator)
  8. mysql> SELECT * FROM test1 WHERE MATCH('"test doc"/3') \G
  9. *************************** 1\. row ***************************
  10.         id: 4
  11.     weight: 2500
  12.   group_id: 2
  13. date_added: 1231721236
  14. 1 row in set, 1 warning (0.00 sec)
  16. mysql> SHOW WARNINGS \G
  17. *************************** 1\. row ***************************
  18.   Level: warning
  19.    Code: 1000
  20. Message: quorum threshold too high (words=2, thresh=3); replacing quorum operator
  21.          with AND operator
  22. 1 row in set (0.00 sec)

SHOW VARIABLES

  1. SHOW [{GLOBAL | SESSION}] VARIABLES LIKE 'pattern'

It returns the current values of a few server-wide variables. Also, support for GLOBAL and SESSION clauses was added.

  1. mysql> SHOW GLOBAL VARIABLES;
  2. +--------------------------+-----------+
  3. | Variable_name            | Value     |
  4. +--------------------------+-----------+
  5. | autocommit               | 1         |
  6. | collation_connection     | libc_ci   |
  7. | query_log_format         | sphinxql  |
  8. | log_level                | info      |
  9. | max_allowed_packet       | 134217728 |
  10. | character_set_client     | utf8      |
  11. | character_set_connection | utf8      |
  12. | grouping_in_utc          | 0         |
  13. | last_insert_id           | 123, 200  |
  14. +--------------------------+-----------+
  15. 9 rows in set (0.00 sec)
  1. mysql> show variables like '%log%';
  2. +------------------+----------+
  3. | Variable_name    | Value    |
  4. +------------------+----------+
  5. | query_log_format | sphinxql |
  6. | log_level        | info     |
  7. +------------------+----------+
  8. 2 rows in set (0.00 sec)
  1. mysql> show session variables like 'autocommit';
  2. +---------------+-------+
  3. | Variable_name | Value |
  4. +---------------+-------+
  5. | autocommit    | 0     |
  6. +---------------+-------+
  7. 1 row in set (0.00 sec)

SHOW COLLATION

  1. SHOW COLLATION

This is currently a placeholder query that does nothing and reports success. That is in order to keep compatibility with frameworks and connectors that automatically execute this statement.

  1. mysql> SHOW COLLATION;
  2. Query OK, 0 rows affected (0.00 sec)