How can we eliminate duplicate values from lookup without overriding sql?

Question

Suppose if we have duplicate records in a table temp_n. Now I want to pass unique values to t1 and duplicate values to t2 in single mapping? How can we achieve?

Answer 1

For this lookup itself eliminate duplicate rows by having options like First Value,Last Value.So whenever there are more than one row for matching lookup condition then it gets eliminated by first value.last Value option.