How To Use PRIMARY KEY Constraint In SQL
In this article, we will learn how to use the Primary Key constraint in SQL.
The PRIMARY KEY constraint is used to identify each record uniquely in a table.
In this article, we will learn how to use the Primary Key constraint in SQL.
The PRIMARY KEY constraint is used to identify each record uniquely in a table.
In this article, we will learn how to use the UNIQUE constraint in SQL.
The UNIQUE constraint is used to ensure that all values in a column are different.
In this article, we will learn how to use the NOT NULL constraint in SQL.
A column can hold NULL values by default. The NOT NULL constraint is used to enforce a column to NOT accept NULL values.
In this article, we will learn how to use the ALTER TABLE statement in SQL.
To add or delete or modify columns in an existing table, the ALTER TABLE statement is used.
The ALTER TABLE statement also can be used to add or drop various constraints on an existing table.
In this article, we will learn how to use the TRUNCATE TABLE statement in SQL.
To delete the data inside a table, but not the table itself, the TRUNCATE TABLE statement is used.
In this article, we will learn how to delete/drop a Table using SQL query.
To drop an existing table in a database, the DROP TABLE statement is used.
In this article, we will learn how to create a Table using SQL query.
To create a new table in a database, the CREATE TABLE statement is used.