Answer-Table Employee(EmpID, ManagerID) has 6 rows: (1,NULL), (2,1), (3,1), (4,2), (5,2), (6,3). How many r...

This self-join matches each employees ManagerID to an existing EmpID. Row 1,NULL is excluded because NULL never satisfies an equality join condition. The remaining five rows 2,1,3,1,4,2,5,2,6,3 each have a ManagerID that matches an existing EmpID in the table, producing exactly 5 matching rows.

Question

Table Employee(EmpID, ManagerI

D has 6 rows: (1,NUL
L , (2,1), (3,1), (4,2), (5,2), (6,3). How many rows will the following self-join return? SELECT E.EmpID, M.EmpID FROM Employee E JOIN Employee M ON E.ManagerID = M.EmpID;