Question

i am trying to know the data is getting loaded in single byte or double byte data, please find the column data as pasted below:

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select CTD_BENAC_NAME 
from NAME_TRAN_DETAILS 
where CTD_SEND_INS_REF ='FTSCWOK11074799'

it will gives the arabic data in the result, now i just want to know data is getting loaded in Single byte or double byte in Sqlserver, kindly advice how can i decide?

Answer 1

It depends on the data type of that column. In SQL Server there are two kinds of character data types — regular and Unicode. Regular data types which are CHAR and VARCHAR. Unicode data types like NCHAR and NVARCHAR. For regular characters SQL Server uses one byte of storage for each character, whereas Unicode characters NVARCHAR uses two bytes per character.

You can also get the number of bytes used by a string using DATALEGNTH or LEN like so:

SELECT DATALENGTH(inputstring); 

As I explained later, If this inputstring is of type NVARCHAR or N'string' DATALENGTH will give you the number of bytes. Whereas the LEN will give you the nuber of characters in a sting and that length is not necessarily the number of bytes.

Note that, another difference between LEN and DATALENGTH is that the LEN excludes trailing blanks while the DATALENGTH doesn’t. Also, be careful with theses functions because it would depend in the collation because Varchar = single byte is not always true as pointed out by @MartinSmith comment below.

Here is a demo for that, you can try it yourself.

DEMO