Question

I’m under the impression that SQL Server will allow me to perform addition such as

SELECT     val01, val02, val03 = (val01 + val02)
FROM       Table_1

so that val03 is the addition of the two previous columns. However, in this instance I am literally seeing value 1 next to value 2. Can you show me where I’m going wrong?

Answer 1

The + operator has two uses in SQL Server:

• For numbers (int, bigint, decimal, etc) it is an ADDITION operator.
• For strings (varchar, nvarchar, char, etc) it is a CONCATENATION operator.

If you have numerical data in a string datatype field, you will see the second value appended to the first.

The solution is to either:

• Use correct datatypes. If it’s a number, the datatype should be numerical.
• CAST to the correct datatype – i.e. val03 = (CAST(val01 as int) + CAST(val02 as INT))