T-SQL DATALENGTH() Function

The T-SQL (Transact-SQL) DATALENGTH() function returns the number of bytes used to represent the specified string expression.

Note: To count the number of characters of the string expression, LEN() function can be used. Note that, it excludes trailing spaces in the length calculation.

Syntax

DATALENGTH(string)

Parameters

Return Value

Returns the number of bytes used to represent the specified string.

Example 1:

The example below shows the usage of DATALENGTH() function.

SELECT DATALENGTH('12345');
Result: 5

SELECT DATALENGTH('ABCDE');
Result: 5

SELECT DATALENGTH(10);
Result: 4

SELECT DATALENGTH('AlphaCodingSkills');
Result: 17

SELECT DATALENGTH('Alpha Coding Skills');
Result: 19

SELECT DATALENGTH(NULL);
Result: NULL

SELECT DATALENGTH('');
Result: 0

SELECT DATALENGTH(' ');
Result: 1

Example 2:

Consider a database table called Employee with the following records:

The statement given below can be used to get the number of bytes used to represent the records of City column.

SELECT *, DATALENGTH(City) AS DATALENGTH_Value FROM Employee;

The query will produce the following result: