When executing a query I am getting the following error: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
How do you fix this error?
ALTER PROCEDURE [dbo].[sp_UpdateInstanceTableWithOperatioGroup]
INSERT INTO tblInstance (SupportGroup)
SELECT OperationSupportGroup from tblDatabase join tblInstance on
tblInstance.Instance_id = tblDatabase.Instance_id where tblInstance.DBPlatform = 'MSSQL'