The INFORMATION_SCHEMA.SCHEMATA Table : INFORMATION_SCHEMA « Data Dictionary « MySQL Tutorial

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3. INFORMATION_SCHEMA

A schema is a database, so the SCHEMATA table provides information about databases.

mysql> desc INFORMATION_SCHEMA.SCHEMATA;
+----------------------------+--------------+------+-----+---------+-------+
| Field                      | Type         | Null | Key | Default | Extra |
+----------------------------+--------------+------+-----+---------+-------+
| CATALOG_NAME               | varchar(512) | YES  |     | NULL    |       |
| SCHEMA_NAME                | varchar(64)  | NO   |     |         |       |
| DEFAULT_CHARACTER_SET_NAME | varchar(64)  | NO   |     |         |       |
| DEFAULT_COLLATION_NAME     | varchar(64)  | NO   |     |         |       |
| SQL_PATH                   | varchar(512) | YES  |     | NULL    |       |
+----------------------------+--------------+------+-----+---------+-------+
5 rows in set (0.00 sec)

The following statements are equivalent:

SELECT SCHEMA_NAME AS `Database`
  FROM INFORMATION_SCHEMA.SCHEMATA
  [WHERE SCHEMA_NAME LIKE 'wild']

SHOW DATABASES
  [LIKE 'wild']