LEFT (Transact-SQL)
Applies to:
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
SQL analytics endpoint in Microsoft Fabric
Warehouse in Microsoft Fabric
Returns the left part of a character string with the specified number of characters.
Transact-SQL syntax conventions
Syntax
LEFT ( character_expression , integer_expression )
Note
To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.
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.
Note
If string_expression is of type binary or varbinary, LEFT will perform an implicit conversion to varchar, and therefore will not preserve the binary input.
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).
The integer_expression parameter counts a UTF-16 surrogate character as one character.
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
When using SC collations, the integer_expression parameter counts a UTF-16 surrogate pair as one character. For more information, see Collation and Unicode Support.
Examples
A. Using LEFT with a column
The following example returns the five leftmost characters of each product name in the Product
table of the AdventureWorks2022 database.
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)
Examples: Azure Synapse Analytics and Analytics Platform System (PDW)
C. Using LEFT with a column
The following example returns the five leftmost characters of each product name.
-- Uses AdventureWorks
SELECT LEFT(EnglishProductName, 5)
FROM dbo.DimProduct
ORDER BY ProductKey;
D. Using LEFT with a character string
The following example uses LEFT
to return the two leftmost characters of the character string abcdefg
.
-- Uses AdventureWorks
SELECT LEFT('abcdefg',2) FROM dbo.DimProduct;
Here is the result set.
--
ab
See Also
LTRIM (Transact-SQL)
RIGHT (Transact-SQL)
RTRIM (Transact-SQL)
STRING_SPLIT (Transact-SQL)
SUBSTRING (Transact-SQL)
TRIM (Transact-SQL)
CAST and CONVERT (Transact-SQL)
Data Types (Transact-SQL)
String Functions (Transact-SQL)