Len() vs datalength() in SQL Server 2005
Be careful. DATALENGTH returns the number of bytes used, not the number of characters.
datalength
count number of characters in nvarchar column
You can find the number of characters using system function LEN. i.e. SELECT LEN(Column) FROM TABLE
What is the size of a image field content in SQL Server?
SELECT DATALENGTH(imagecol) FROM table See MSDN
SQL Server 2008 Empty String vs. Space
varchars and equality are thorny in TSQL. The LEN function says: Returns the number of characters, rather than the number of bytes, of the given string expression, excluding trailing blanks. You need to use DATALENGTH to get a true byte count of the data in question. If you have unicode data, note that the value … Read more