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Php add column to table


Altering Tables

Existing tables can be altered using the mysql_query() function.

You can add or modify fields or columns in an existing table.

You can delete fields.

You can even delete an entire table and start over.

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Add a Column or Field to a Table

To add a column to an existing table the syntax would be:
mysql_query("ALTER TABLE birthdays ADD street CHAR(30)");

You can also specify where you want to add the field.
mysql_query("ALTER TABLE birthdays ADD street CHAR(30) AFTER birthday");

The simple bit of code shown above would add a new column to the birthdays table named street after birthday. Type and size are also set in the statement.

You can also add multiple fields:

mysql_query("ALTER TABLE birthdays
ADD street CHAR(30) AFTER birthday,
Add city CHAR(30) AFTER street,
ADD state CHAR(4) AFTER city,
ADD zipcode CHAR(20) AFTER state,
ADD phone CHAR(20) AFTER zipcode");

Modify a Column or Field

Column definitions can be modified using the ALTER method. The following code would change the existing birthday column from 7 to 15 characters.

mysql_query("ALTER TABLE birthdays CHANGE birthday birthday VARCHAR(15)");

In the example the column to alter is first named and then the new definition is supplied which includes the column name


Remove a Column or Field

Columns can be removed from an existing table. The next example of code would remove the lastname column.
mysql_query("ALTER TABLE birthdays DROP lastname");

Remove a Table

Be careful with this code. It will remove an entire table and all of its contents from your database.
mysql_query("DROP TABLE table_name");

This script is included in the download zip file. If you run it, you will need to add the new fields to all of the existing scripts.

Copy & Save as: birthdays_add_fields.php

You should only run this script if you want to increase your knowledge by getting a little practice in updating the existing scripts.

Note: All ofhe operations covered above can be performed from the phpMyAdmin panel.