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LEFT (Transact-SQL)

Returns the left part of a character string with the specified number of characters.

Topic link iconTransact-SQL Syntax Conventions

Syntax

LEFT (character_expression , integer_expression )

Arguments

  • character_expression
    Is an expression of character or binary data. character_expression can be a constant, variable, or column. character_expression can be of any data type, except text or ntext, that can be implicitly converted to varchar or nvarchar. Otherwise, use the CAST function to explicitly convert character_expression.

  • integer_expression
    Is a positive integer that specifies how many characters of the character_expression will be returned. If integer_expression is negative, an error is returned. If integer_expression is type bigint and contains a large value, character_expression must be of a large data type such as varchar(max).

Return Types

Returns varchar when character_expression is a non-Unicode character data type.

Returns nvarchar when character_expression is a Unicode character data type.

Remarks

Compatibility levels can affect return values. For more information about compatibility levels, see sp_dbcmptlevel (Transact-SQL).

Examples

A. Using LEFT with a column

The following example returns the five leftmost characters of each product name.

USE AdventureWorks;
GO
SELECT LEFT(Name, 5) 
FROM Production.Product
ORDER BY ProductID;
GO

B. Using LEFT with a character string

The following example uses LEFT to return the two leftmost characters of the character string abcdefg.

SELECT LEFT('abcdefg',2)
GO

Here is the result set.

-- 
ab 

(1 row(s) affected)