Learn how to use CREATE TABLE, ALTER TABLE, and CONSTRAINT to create, modify, and view primary and foreign keys in SQL DB2 tables.

Define a primary key in the SQL Server Database Engine by using SQL Server Management Studio or Transact-SQL. Creating a new table with a primary key requires CREATE TABLE permission in the database ...

The first form of the CREATE TABLE statement creates tables that automatically map SQL data types to those supported by the SAS System. Use this form when you want to create a new table with columns ...

In mysql, the primary key constraint is used to uniquely identify each record in a table.primary key contains unique values only and the column defined as primary key column can not be null. a table ...

The primary key column is often set to auto-increment when constructing a SQL Server database. To achieve this, the IDENTITY property is enabled on the primary key column. The starting value and ...

A table can contain only one PRIMARY KEY constraint. All columns defined within a PRIMARY KEY constraint must be defined as NOT NULL. If nullability is not specified, all columns participating in a ...