回滚错误SQL Server 2008

Question

I found an weird thing in SQL Server 2008 today. I write a ROUND function, and I test this randomly.

From 9.50-9.99, this line of code:

SELECT ROUND(X.XX, 0);  

throws this error:

An error occurred while executing batch.
Error message is: Arithmetic Overflow.

but from 9.00-9.49 it is working just fine.

Can anybody please let me know what's wrong with that code?

Answer 1

This is because it is trying to implicitly fit this into a numeric(3,2) datatype, which 10.00 will over flow. You need to cast it to a larger datatype: select round(cast(9.50 as numeric(4,2)),0)

You can run this code to see what the implicit datatype & precision is:

select SQL_VARIANT_PROPERTY (cast(9.50 as SQL_VARIANT), 'BaseType'),
         SQL_VARIANT_PROPERTY (cast(9.50 as SQL_VARIANT), 'Precision'),
         SQL_VARIANT_PROPERTY (cast(9.50 as SQL_VARIANT), 'Scale')