DATALENGTH (Transact-SQL)

Returns the number of bytes used to represent any expression.

Transact-SQL Syntax Conventions

Syntax

DATALENGTH ( expression ) 

Arguments

• expression
  Is an expression of any data type.

Return Types

bigint if expression is of the varchar(max), nvarchar(max) or varbinary(max) data types; otherwise int.

Remarks

DATALENGTH is especially useful with varchar, varbinary, text, image, nvarchar, and ntext data types because these data types can store variable-length data.

The DATALENGTH of NULL is NULL.

Note

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

Examples

The following example finds the length of the Name column in the Product table.

USE AdventureWorks2012;
GO
SELECT length = DATALENGTH(Name), Name
FROM Production.Product
ORDER BY Name;
GO

See Also

Reference

LEN (Transact-SQL)

CAST and CONVERT (Transact-SQL)

Data Types (Transact-SQL)

System Functions (Transact-SQL)