Question

I’m using SQL Server 2008.

I have found the LEN function does not return a zero when it evaluates an integer when the integer has no value – it returns a 1.

For example:

declare @int1 int
set @int1 = ''
select LEN(@int1)

A 1 is returned instead of a zero! But the integer is zero-length!

Why is this? Is it a bug?

Answer 1

An INT doesn’t have a length. This is what you are actually doing…

• Create an INT variable
• Create a zero length string ''
• CAST that string to an INT 0
• Assign the result to the variable
• CAST the variable’s value to a STRING '0'
• Caclulate the length of that string

The result of which is that your LEN function is not being called on ”, but is infact being called on ‘0’, which has a length of 1.