Question

mysql> select from Staff: I staffNo | fName LName position sex DOB |SA9 Mary Howe Assistant F1970-02-19|9000,00 |B007 SG14 I salary |branchNo | managerNo | SG14 David | Ford Supervisor |M 1958-03-24| 18000.00 |B003 SG5 SG37 Ann Beech Assistant IF 1960-11-10 | 12000.00 |B003 SL21 SG5 Susan | Brand |Manager F1940-06-03 |24000.00 B003 SG14 | SL21 John | White I Manager M1945-10-01I 30000.00 | B005I XYZ1 | SL41 Julie | Lee Assistant IF I 1965-06-13 9000.00 B005 XYZi M 1970-01-01 40000.00 I B002 NULL | XYZ1 Huang Austin | CE0 7 rows in set 〔0.00 sec)

1. listing staff first name, position and their manage first names and positions for all male staff. The output header needs to distinguish between staff and manger.

the answer should be like this

Answer 1

you can use the Self join or left join to get the desired view for example the SQL statement would look like

CREATE VIEW AS

SELECT s1.fName staffName,s1.position staffPosition,s2.fName managerName,s2.position managerPosition

FROM Staff s1

LEFT JOIN Staff s2

ON s1.managerNo = s2.staffNo

Here we are creating two instances of the same table and we are matching/joining based on the managerNo from the first table to the staffNo from the second table.