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。

USE INFORMATION_SCHEMA;
DESC SCHEMATA;

结果如下：

+----------------------------+--------+------+------+---------+---------------+
| Column                     | Type   | Key  | Null | Default | Semantic Type |
+----------------------------+--------+------+------+---------+---------------+
| catalog_name               | String |      | NO   |         | FIELD         |
| schema_name                | String |      | NO   |         | FIELD         |
| default_character_set_name | String |      | NO   |         | FIELD         |
| default_collation_name     | String |      | NO   |         | FIELD         |
| sql_path                   | String |      | YES  |         | FIELD         |
+----------------------------+--------+------+------+---------+---------------+
5 rows in set (0.00 sec)

SELECT * FROM SCHEMATA;

+--------------+--------------------+----------------------------+------------------------+----------+
| catalog_name | schema_name        | default_character_set_name | default_collation_name | sql_path |
+--------------+--------------------+----------------------------+------------------------+----------+
| greptime     | greptime_private   | utf8                       | utf8_bin               | NULL     |
| greptime     | information_schema | utf8                       | utf8_bin               | NULL     |
| greptime     | public             | utf8                       | utf8_bin               | NULL     |
+--------------+--------------------+----------------------------+------------------------+----------+
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。