Declare

DECLARE sets a variable to the value of an expression. The variable can then be used, with its @ prefix, in the statements that follow it in the same script.

Declares a number and uses it in a WHERE clause.

DECLARE @Language = 2
SELECT Text FROM WordList:Word WHERE LanguageId = @Language

Declares the result of an expression.

DECLARE @Pattern = 'Cat' + '%'
SELECT Text FROM WordList:Word WHERE Text LIKE @Pattern

Uses a variable in the field list.

DECLARE @Greeting = 'Hello'
SELECT @Greeting + ' ' + Text as Message FROM WordList:Word WHERE Id = 1

• Set
• Expressions