Displaying Database Structure with SHOW
Details of databases, tables, and indexes can be displayed with the SHOW command. The SHOW command isn't part of the SQL standard and is MySQL-specific. It can be used in several ways:
- SHOW DATABASES
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Lists the databases that are accessible by the MySQL DBMS.
- SHOW TABLES
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Shows the tables in the database once a database has been selected with the use command.
- SHOW COLUMNS FROM tablename
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Shows the attributes, types of attributes, key information, whether NULL is permitted, defaults, and other information for a table. For example:
SHOW COLUMNS FROM customer
shows the attribute information for the customer table. DESCRIBE table produces the same output.
- SHOW INDEX FROM tablename
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Presents the details of all indexes on the table, including the PRIMARY KEY. For example:
SHOW INDEX FROM customer
shows that there are two indexes, the primary index and the names index.
- SHOW STATUS
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Reports details of the MySQL DBMS performance and statistics.