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。
sql
USE INFORMATION_SCHEMA;
DESC SCHEMATA;USE INFORMATION_SCHEMA;
DESC SCHEMATA;结果如下：
sql
+----------------------------+--------+------+------+---------+---------------+
| 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)+----------------------------+--------+------+------+---------+---------------+
| 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)sql
SELECT * FROM SCHEMATA;SELECT * FROM SCHEMATA;sql
+--------------+--------------------+----------------------------+------------------------+----------+
| 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)+--------------+--------------------+----------------------------+------------------------+----------+
| 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。