Creating a Database and a Sample Table

1.3.1 Problem

You want to create a database and to set up tables within it.

1.3.2 Solution

Use a CREATE DATABASE statement to create a database, a CREATE TABLE statement for each table you want to use, and INSERT to add records to the tables.

1.3.3 Discussion

The GRANT statement used in the previous section defines privileges for the cookbook database, but does not create it. You need to create the database explicitly before you can use it. This section shows how to do that, and also how to create a table and load it with some sample data that can be used for examples in the following sections.

After the cbuser account has been set up, verify that you can use it to connect to the MySQL server. Once you've connected successfully, create the database. From the host that was named in the GRANT statement, run the following commands to do this (the host named after -h should be the host where the MySQL server is running):

% mysql -h localhost -p -u cbuser Enter password: cbpass mysql> CREATE DATABASE cookbook; Query OK, 1 row affected (0.08 sec)

Now you have a database, so you can create tables in it. Issue the following statements to select cookbook as the default database, create a simple table, and populate it with a few records:[1]

[1] If you don't want to enter the complete text of the INSERT statements (and I don't blame you), skip ahead to Recipe 1.13 for a shortcut. And if you don't want to type in any of the statements, skip ahead to Recipe 1.16.

mysql> USE cookbook; mysql> CREATE TABLE limbs (thing VARCHAR(20), legs INT, arms INT); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('human',2,2); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('insect',6,0); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('squid',0,10); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('octopus',0,8); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('fish',0,0); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('centipede',100,0); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('table',4,0); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('armchair',4,2); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('phonograph',0,1); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('tripod',3,0); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('Peg Leg Pete',1,2); mysql> INSERT INTO limbs (thing,legs,arms) VALUES('space alien',NULL,NULL);

The table is named limbs and contains three columns to records the number of legs and arms possessed by various life forms and objects. (The physiology of the alien in the last row is such that the proper values for the arms and legs column cannot be determined; NULL indicates "unknown value.")

Verify that the table contains what you expect by issuing a SELECT statement:

mysql> SELECT * FROM limbs; +--------------+------+------+ | thing | legs | arms | +--------------+------+------+ | human | 2 | 2 | | insect | 6 | 0 | | squid | 0 | 10 | | octopus | 0 | 8 | | fish | 0 | 0 | | centipede | 100 | 0 | | table | 4 | 0 | | armchair | 4 | 2 | | phonograph | 0 | 1 | | tripod | 3 | 0 | | Peg Leg Pete | 1 | 2 | | space alien | NULL | NULL | +--------------+------+------+ 12 rows in set (0.00 sec)

At this point, you're all set up with a database and a table that can be used to run some example queries.