| title | summary |
|---|---|
SESSION_VARIABLES |
了解 INFORMATION_SCHEMA 表 `SESSION_VARIABLES`。 |
SESSION_VARIABLES 表提供了关于 session 变量的信息。表中的数据跟 SHOW SESSION VARIABLES 语句执行结果类似。
USE INFORMATION_SCHEMA;
DESC SESSION_VARIABLES;输出结果如下：
+----------------+---------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------+---------------+------+------+---------+-------+
| VARIABLE_NAME | varchar(64) | YES | | NULL | |
| VARIABLE_VALUE | varchar(1024) | YES | | NULL | |
+----------------+---------------+------+------+---------+-------+
2 rows in set (0.00 sec)查看 SESSION_VARIABLES 表的前 10 条信息：
SELECT * FROM SESSION_VARIABLES ORDER BY variable_name LIMIT 10;输出结果如下：
+-----------------------------------+------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+-----------------------------------+------------------+
| allow_auto_random_explicit_insert | OFF |
| auto_increment_increment | 1 |
| auto_increment_offset | 1 |
| autocommit | ON |
| automatic_sp_privileges | 1 |
| avoid_temporal_upgrade | OFF |
| back_log | 80 |
| basedir | /usr/local/mysql |
| big_tables | OFF |
| bind_address | * |
+-----------------------------------+------------------+
10 rows in set (0.00 sec)SESSION_VARIABLES 表各列字段含义如下：
VARIABLE_NAME：数据库中 session 级变量的名称。VARIABLE_VALUE：数据库中对应该 session 变量名的具体值。