Mysql Alter

Drop Column Syntax

Sometimes we will wish to delete a column from an existing table in SQL. To do this, we specify that we want to change the table structure via the ALTER TABLE command, followed by a specification indicating that we want to remove a column. The detailed syntax for each database is as follow:

In MySQL, the syntax for ALTER TABLE Drop Column is,

ALTER TABLE "table_name"
DROP "column_name";

In Oracle and SQL Server, the syntax for ALTER TABLE Drop Column is,

ALTER TABLE "table_name"
DROP COLUMN "column_name";

Let's look at the example. Assuming our starting point is the Customer table created in the CREATE TABLE section:

Table Customer

Column Name	Data Type
First_Name	char(50)
Last_Name	char(50)
Address	char(50)
City	char(50)
Country	char(25)
Birth_Date	datetime

Our goal is to drop the "Birth_Date" column. To do this, we key in:

MySQL:

ALTER TABLE Customer DROP Birth_Date;

SQL Server:

ALTER TABLE Customer DROP COLUMN Birth_Date;

Oracle:

ALTER TABLE Customer DROP COLUMN Birth_Date;

The resulting table structure is:

Table Customer

Column Name	Data Type
First_Name	char(50)
Last_Name	char(50)
Address	char(50)
City	char(50)
Country	char(25)