SET [GLOBAL|SESSION]

SET [GLOBAL|SESSION] 语句用于在 SESSION 或 GLOBAL 的范围内，对某个 TiDB 的内置变量进行更改。需注意，对 GLOBAL 变量的更改不适用于已有连接或本地连接，这与 MySQL 类似。只有新会话才会反映值的变化。

语法图

SetStmt:

SetStmt

示例

  1. mysql> SHOW GLOBAL VARIABLES LIKE 'sql_mode';
  2. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  3. | Variable_name | Value                                                                                                                                     |
  4. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  5. | sql_mode      | ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
  6. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  7. 1 row in set (0.00 sec)
  9. mysql> SHOW SESSION VARIABLES LIKE 'sql_mode';
  10. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  11. | Variable_name | Value                                                                                                                                     |
  12. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  13. | sql_mode      | ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
  14. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  15. 1 row in set (0.00 sec)
  17. mysql> SET GLOBAL sql_mode = 'STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER';
  18. Query OK, 0 rows affected (0.03 sec)
  20. mysql> SHOW GLOBAL VARIABLES LIKE 'sql_mode';
  21. +---------------+-----------------------------------------+
  22. | Variable_name | Value                                   |
  23. +---------------+-----------------------------------------+
  24. | sql_mode      | STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER |
  25. +---------------+-----------------------------------------+
  26. 1 row in set (0.00 sec)
  28. mysql> SHOW SESSION VARIABLES LIKE 'sql_mode';
  29. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  30. | Variable_name | Value                                                                                                                                     |
  31. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  32. | sql_mode      | ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
  33. +---------------+-------------------------------------------------------------------------------------------------------------------------------------------+
  34. 1 row in set (0.00 sec)
  36. mysql> SET SESSION sql_mode = 'STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER';
  37. Query OK, 0 rows affected (0.01 sec)
  39. mysql> SHOW SESSION VARIABLES LIKE 'sql_mode';
  40. +---------------+-----------------------------------------+
  41. | Variable_name | Value                                   |
  42. +---------------+-----------------------------------------+
  43. | sql_mode      | STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER |
  44. +---------------+-----------------------------------------+
  45. 1 row in set (0.00 sec)

MySQL 兼容性

SET [GLOBAL|SESSION] 语句与 MySQL 完全兼容。如有任何兼容性差异，请在 GitHub 上提交 issue。

另请参阅