Each declarative integrity constraint can be removed using the DROP clause of the ALTER TABLE statement. : ALTER TABLE « Table « SQL Server / T-SQL Tutorial

5> CREATE TABLE sales
6>         (order_no INTEGER NOT NULL PRIMARY KEY,
7>         order_date DATETIME NOT NULL,
8>         ship_date DATETIME NOT NULL)
9> GO
1>
2> ALTER TABLE sales
3>         ADD CONSTRAINT order_check CHECK(order_date <= ship_date)
4> GO
1>
2>
3> ALTER TABLE sales
4>       DROP CONSTRAINT order_check
5> GO
1>
2> drop table sales;
3> GO

3.2.ALTER TABLE
	3.2.1.	The basic syntax of the ALTER TABLE statement
	3.2.2.	drop column syntax
	3.2.3.	Change the length of the emp_name column in the employee table from varchar(30) to varchar(50)
	3.2.4.	Alter table to add a constraint based on IN function
	3.2.5.	Altering a Table: A Basic Form
	3.2.6.	Alter table to add column
	3.2.7.	Alter table to drop a column
	3.2.8.	The DROP COLUMN clause provides the ability to drop an existing column of the table.
	3.2.9.	ALTER data size for a COLUMN
	3.2.10.	Altering a Table: Enhanced Form
	3.2.11.	Use ALTER TABLE statement to define the primary key
	3.2.12.	Use ALTER TABLE statement to define the foreign key of a table.
	3.2.13.	Each declarative integrity constraint can be removed using the DROP clause of the ALTER TABLE statement.
	3.2.14.	Expanded nvarchar(20) to nvarchar(300)
	3.2.15.	Creating a Computed Column in alter table command
	3.2.16.	Create a Table Index