To create a table ... primary or foreign key constraint, you need to use the ALTER TABLE statement and specify the name of the table and the constraint. To modify a constraint, you can use the ADD ...

Adding a primary key using ALTER Command: Alter command is generally used to modify table . It can be used to add columns or to remove columns. Using Alter command we can also add or remove a key from ...

ALTER TABLE customer ADD CONSTRAINT pk_customer PRIMARY KEY USING INDEX pk_customer; ALTER TABLE lineitem ADD CONSTRAINT pk_lineitem PRIMARY KEY USING INDEX pk_lineitem; ALTER TABLE nation ADD ...

ALTER TABLE `ages` ALTER `AGEID` DROP DEFAULT; ALTER TABLE `ages` CHANGE COLUMN `AGEID` `AGEID` INT(11) NOT NULL FIRST, ADD PRIMARY KEY (`AGEID`); ALTER TABLE `arestorg` ALTER `ARESTORGANID` DROP ...

Cascading referential integrity constraints are foreign key constraints that tell SQL Server to perform ... tables that were related to the primary key table. Let’s look at how these constraints ...