Programming language | computer science | Technology Information | DDL SCRIPT

DDL is a sub language whose function is to define the SQL database and tables. The commands used are: CREATE, ALTER, and DROP.
Jump ajah well, so the table creation commands you are not experiencing the error, create a database electronicdb and then activate with the following example:

and switch on or connect it with the following command:

After you run the second command has been entered into the database electronikdb, and you can create a table in the database is active.

To understand the command to create a simple table, the condition you should already know what tables you will create, then image data to be stored in it. By using the command:

if it has been completed on the do command as above and there is no error, you can see and check with SHOW TABLES command as shown below:

Then we go back to the command to create a table tipe_barang:

Well, now my friends already have electronikdb database with two tables already contained in it, namely tables and tables jenis_barang tipe_barang.

There again, the SQL language, the command ALTER able to assist us in changing the data and its provisions when we forget to make during the first defines the table. You can change the column names, table names, add column, add primary key, delete the columns that exist there. For example, if we want to add a new column named description of type TEXT on jenis_barang table, the command as follows:

and you can see it with the command:
mysql> desc jenis_barang;

By using the same way, you can add a new column on the first part. For that, use the FIRST parameter, such as the following:
SYNTAX: alter table table_name add kolom_baru type (length) [FIRST | AFTER kolom_lama]

There is another command to change the name column:
SYNTAX: alter table table_name CHANGE kolom_lama kolom_baru type (length)
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and as usual, can be checked using desc command.

The latter is in the SQL DROP command is used to remove components of an existing table. You can remove the primary key, or delete the table. Let not curious, straight at aja peep like the ways below.
To remove the primary key, you can use the DROP command. With a command like the following:
SYNTAX: alter table table_name DROP primary key

To delete a table column, with the following syntax and command as follows:
SYNTAX: alter table table_name DROP column_name

sources http://haidinda.wordpress.com/2009/01/09/menguasai-perintah-ddl/