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5 maj 2023 · This topic describes how to create a unique index on a table in SQL Server by using SQL Server Management Studio or Transact-SQL. A unique index guarantees that the index key contains no duplicate values and therefore every row in the table is in some way unique.
The following SQL creates an index named "uidx_pid" on the "PersonID" column in the "Persons" table: CREATE UNIQUE INDEX uidx_pid. ON Persons (PersonID); Note: The syntax for creating indexes varies among different databases. Therefore: Check the syntax for creating indexes in your database.
E. Create a unique nonclustered index. The following example creates a unique nonclustered index on the Name column of the Production.UnitMeasure table in the AdventureWorks2022 database. The index will enforce uniqueness on the data inserted into the Name column. CREATE UNIQUE INDEX AK_UnitMeasure_Name ON Production.UnitMeasure(Name);
To create a unique index, you use the CREATE UNIQUE INDEX statement as follows: CREATE UNIQUE INDEX index_name ON table_name(column_list); Code language: SQL (Structured Query Language) (sql) In this syntax: First, specify the name of the unique index after the CREATE UNIQUE INDEX keywords.
CREATE UNIQUE INDEX index_name ON table_name|view_name(column_list); In this syntax, UNIQUE – keyword which tells SQL Server to create the new index as a unique index. table_name|view_name –the name of the table or view on which the unique index is to be created. It can be either one.
Using SQL Server 2008, you can create a filtered index. CREATE UNIQUE INDEX AK_MyTable_Column1 ON MyTable (Column1) WHERE Column1 IS NOT NULL. Another option is a trigger to check uniqueness, but this could affect performance. edited Mar 30, 2022 at 7:54.
Introduce the nonclustered indexes and show how to use the SQL Server CREATE INDEX statement to create nonclustered indexes.
