Getting Information About Databases and Tables
==============================================


provide information about the databases and tables it supports.

You have already seen `SHOW DATABASES', which lists the databases
managed by the server.  To find out which database is currently
selected, use the `DATABASE()' function:

     mysql> SELECT DATABASE();
     +------------+
     | DATABASE() |
     +------------+
     | menagerie  |
     +------------+

If you haven't selected any database yet, the result is `NULL' (or the
empty string before MySQL 4.1.1).

To find out what tables the current database contains (for example, when
you're not sure about the name of a table), use this command:

     mysql>If you want to find out about the structure of a table, the `DESCRIBE'
command is useful; it displays information about each of a table's
columns:

     mysql> DESCRIBE pet;
     +---------+-------------+------+-----+---------+-------+
     | Field   | Type        | Null | Key | Default | Extra |
     +---------+-------------+------+-----+---------+-------+
     | name    | varchar(20) | YES  |     | NULL    |       |
     | owner   | varchar(20) | YES  |     | NULL    |       |
     | species | varchar(20) | YES  |     | NULL    |       |
     | sex     | char(1)     | YES  |     | NULL    |       |
     | birth   | date        | YES  |     | NULL    |       |
     | death   | date        | YES  |     | NULL    |       |
     +---------+-------------+------+-----+---------+-------+

`Field' indicates the column name, `Type' is the datatype for the
column, `NULL' indicates whether the column can contain `NULL' values,
`Key' indicates whether the column is indexed, and `Default' specifies
the column's default value.

If you have indexes on a table, `SHOW INDEX FROM tbl_name' produces
information about them.

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