SQL UNIQUE Constraint. The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for …

Mar 7, 2025 · In this article, we will explore the SQL UNIQUE Constraint in detail, including its syntax, usage, and examples. What is the SQL UNIQUE Constraint? The SQL UNIQUE …

SQL UNIQUE Constraint Syntax. The syntax of the SQL UNIQUE constraint is: CREATE TABLE table_name ( column_name data_type UNIQUE ); Here, table_name is the name of the table …

In this syntax, you use the UNIQUE keyword to create a unique constraint for the column1 when creating the table. This UNIQUE constraint is a column constraint because we define it in the …

Mar 3, 2024 · When it comes to ensuring data integrity in your databases, knowing how to properly implement the UNIQUE constraint is key. This constraint prevents duplicate entries in …

The syntax for creating a unique constraint using an ALTER TABLE statement in SQL Server is: ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column1, …

Define Primary Keys: UNIQUE constraints are often used to define primary keys, which uniquely identify each row in a table. Syntax. The syntax for creating a UNIQUE constraint in SQL …

The UNIQUE key constraint is used for ensuring that all values in a column or a set of columns are unique. This chapter covered the basic syntax for defining UNIQUE keys, inserting data …

Use following syntax to drop the unique constraint. Next Topic: SQL INDEX Constraint with example. Previous Topic: SQL NOT NULL Constraint with example. Sql unique constraint …

Learn about the SQL UNIQUE constraint, its purpose, and how to implement it effectively in your database to ensure data integrity.