When is lookup required in queries?

[Harrold]

Hi

1) When is lookup required in queries?
2) What is the difference being using the original source and using lookup? eg in Query 1, both TblSalary and TblEmployee_Detailed have Employee ID. Hence does it matter where i select the employee ID from?

Thanks

 

[jzwp22]

I'm not sure what you mean by lookups in your first question. Could you explain a little further?

Regarding question 2, as long as you have an inner join between the two tables, it would not matter which field you choose. That is not the case if you use a left or right join.