SQLSERVER_5: Alter, Rename and Drop Command

SQL Server provides Alter and Drop commands for dropping tables and Database, as well changing the structure of Table.

i. Drop

This command is used to drop the Table or Database. We can use the command is the following way:

Drop Table Dept - This command will drop the table named “DEPT”

Drop Database Test - This command will drop the database named “TEST”

ii. Alter

This command is used to alter the Structure of Table. We can add, remove columns or even constraints with the help of this command.

Alter table emptemp add address varchar(20)

The above command will add a new column named “address” in the table called “emptemp”

Alter table emptemp drop column address

The above command will delete column named “address” in the table called “emptemp”

Alter table emptemp alter column address varchar(200)

The above command will change the column length to 200 for address.

iii. Renaming Table

We can also rename a SQL Server table. The following command depicts renaming of the table named “emptemp” to “empnew”

sp_rename 'emptemp', 'empnew'

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