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Difference between LEN and DATALENGTH

LEN:
LEN function returns the number of characters in a variable .it also removes the trailing spaces and then
then return the length.

Example-1:

DECLARE @Name VARCHAR(20)='rakesh'
SELECT LEN(@Name) as [len]

Output:






Example-2:

DECLARE @Name VARCHAR(20)='rakesh '
SELECT LEN(@Name) as [len]

Output:

When we observe above variable assigned 'rakesh ' string after that added 3 spaces . Len function removes trailing spaces not leading spaces.

DATALENGTH :
DATALENG function returns the number of bytes occupy in a variable .it also considered the spaces also.

Example-1:

DECLARE @Name VARCHAR(20)='rakesh'
SELECT DATALENGTH(@Name) as [DataLength]

Output:





Example-2:

DECLARE @Name VARCHAR(20)=' rakesh '
SELECT DATALENGTH(@Name) as [DataLength]

Output:






In above example before 'r' and after 'h' we added space that why data length should be 8.

Example-3:

DECLARE @Name NVARCHAR(20)=' rakesh '
SELECT DATALENGTH(@Name) as [DataLength]

Output:






NOTE

In varchar each character is allows 1 byte. It does not support Unicode characters.


In nvarchar each character is allows2 byte. It support's Unicode characters.

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