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 29, 2016 · Add a Unique index to the Description column. Using Sql Server Management Studio right click on the table and choose Design. Then right click on a column and choose …

I have SQL Server 2008 R2 and I want to set a unique column. There seems to be two ways to do this: "unique index" and "unique constraint". They are not much different from what I …

Feb 4, 2025 · You can create a unique constraint in SQL Server by using SQL Server Management Studio or Transact-SQL to ensure no duplicate values are entered in specific …

Nov 5, 2015 · ALTER TABLE tablename ADD UNIQUE (Username) where the table is called tablename and the Username column (which you want to be unique) is called Username. For …

You would like to make a column unique in a given table in a database. Example: We would like to make the column name unique in the table product. The query below presents one way to …

SQL Server UNIQUE constraints allow you to ensure that the data stored in a column, or a group of columns, is unique among the rows in a table. The following statement creates a table …

Sep 13, 2024 · Let’s check out several ways to create a UNIQUE constraint in SQL Server. The most concise way to create a UNIQUE constraint when creating a table is to include it within …

In SQL, a UNIQUE constraint ensures that all values in a column or set of columns are unique within the same table. A UNIQUE constraint helps you maintain the data integrity by …

The syntax for creating a unique constraint using a CREATE TABLE statement in SQL Server is: column1 datatype [ NULL | NOT NULL ], column2 datatype [ NULL | NOT NULL ], ...