LEN (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 number of characters of the specified string expression, excluding trailing spaces.
Note
To return the number of bytes used to represent an expression, use the DATALENGTH function.
Transact-SQL syntax conventions
Syntax
LEN ( string_expression )
Note
To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.
Arguments
string_expression
Is the string expression to be evaluated. string_expression can be a constant, variable, or column of either character or binary data.
Return Types
bigint if expression is of the varchar(max), nvarchar(max) or varbinary(max) data types; otherwise, int.
If you are using SC collations, the returned integer value counts UTF-16 surrogate pairs as a single character. For more information, see Collation and Unicode Support.
Remarks
LEN excludes trailing spaces. If that is a problem, consider using the DATALENGTH (Transact-SQL) function which does not trim the string. If processing a unicode string, DATALENGTH will return a number that may not be equal to the number of characters. The following example demonstrates LEN and DATALENGTH with a trailing space.
DECLARE @v1 VARCHAR(40),
@v2 NVARCHAR(40);
SELECT
@v1 = 'Test of 22 characters ',
@v2 = 'Test of 22 characters ';
SELECT LEN(@v1) AS [VARCHAR LEN] , DATALENGTH(@v1) AS [VARCHAR DATALENGTH];
SELECT LEN(@v2) AS [NVARCHAR LEN], DATALENGTH(@v2) AS [NVARCHAR DATALENGTH];
Note
Use the LEN to return the number of characters encoded into a given string expression, and DATALENGTH to return the size in bytes for a given string expression. These outputs may differ depending on the data type and type of encoding used in the column. For more information on storage differences between different encoding types, see Collation and Unicode Support.
Examples
The following example selects the number of characters and the data in FirstName
for people located in Australia
. This example uses the AdventureWorks database.
SELECT LEN(FirstName) AS Length, FirstName, LastName
FROM Sales.vIndividualCustomer
WHERE CountryRegionName = 'Australia';
GO
Examples: Azure Synapse Analytics and Analytics Platform System (PDW)
The following example returns the number of characters in the column FirstName
and the first and last names of employees located in Australia
.
USE AdventureWorks2022
GO
SELECT DISTINCT LEN(FirstName) AS FNameLength, FirstName, LastName
FROM dbo.DimEmployee AS e
INNER JOIN dbo.DimGeography AS g
ON e.SalesTerritoryKey = g.SalesTerritoryKey
WHERE EnglishCountryRegionName = 'Australia';
Here is the result set.
FNameLength FirstName LastName
----------- --------- ---------------
4 Lynn Tsoflias
See Also
DATALENGTH (Transact-SQL)
CHARINDEX (Transact-SQL)
PATINDEX (Transact-SQL)
LEFT (Transact-SQL)
RIGHT (Transact-SQL)
Data Types (Transact-SQL)
String Functions (Transact-SQL)