SCHEMATA

SCHEMATA 表提供数据库的相关信息。表数据等同于 SHOW DATABASES 语句的结果。

  1. USE INFORMATION_SCHEMA;
  2. DESC SCHEMATA;

结果如下：

  1. +----------------------------+--------+------+------+---------+---------------+
  2. | Column                     | Type   | Key  | Null | Default | Semantic Type |
  3. +----------------------------+--------+------+------+---------+---------------+
  4. | catalog_name               | String |      | NO   |         | FIELD         |
  5. | schema_name                | String |      | NO   |         | FIELD         |
  6. | default_character_set_name | String |      | NO   |         | FIELD         |
  7. | default_collation_name     | String |      | NO   |         | FIELD         |
  8. | sql_path                   | String |      | YES  |         | FIELD         |
  9. +----------------------------+--------+------+------+---------+---------------+
  10. 5 rows in set (0.00 sec)
  1. SELECT * FROM SCHEMATA;
  1. +--------------+--------------------+----------------------------+------------------------+----------+
  2. | catalog_name | schema_name        | default_character_set_name | default_collation_name | sql_path |
  3. +--------------+--------------------+----------------------------+------------------------+----------+
  4. | greptime     | greptime_private   | utf8                       | utf8_bin               | NULL     |
  5. | greptime     | information_schema | utf8                       | utf8_bin               | NULL     |
  6. | greptime     | public             | utf8                       | utf8_bin               | NULL     |
  7. +--------------+--------------------+----------------------------+------------------------+----------+
  8. 3 rows in set (0.01 sec)

SCHEMATA 表中的字段描述如下：

  • catalog_name：数据库所属的目录。
  • schema_name：数据库的名称。
  • default_character_set_name：数据库的默认字符集。
  • default_collation_name：数据库的默认排序规则。
  • sql_path：该项的值始终为 NULL。