Syntax error on comma

[Komala1991]

Hi,

I am trying to change datatype for two columns at a time, but receiving error stating - Incorrect syntax near ','. Syntax is given below.

Alter Table Trail14
Alter Column ID Int,
Alter column Weight Decimal;

Please let me know can Datatype, or alter column or constraint can be changed for multiple columns at a time?

[alaahewwari]

Hi,
In SQL Server, you cannot change the datatype or alter multiple columns or constraints at the same time in a single statement. Each column or constraint must be altered individually with separate ALTER TABLE commands.