mySQL - Multiple rows into one row - mysql

Question

I need data from multiple tables using joins. Below are the tables.
table 1 : list_vehicles
pk_vehicle_id vehicle_reg_no vehicle_type
1 REG1 Bus
2 1 Bus
7 1 Bus
table 2 : list_vehicles
pk_route_id route_code route_name route_description
26 CODE1 Route1 First Route
27 CODE2 Route2 Second Route
28 CODE3 Route3 Third Route
table 3 : tbl_route_vehicle_mgmt
pk_route_veh_id fk_route_id fk_vehicle_id
4 22 2
5 23 1
6 27 1
table 4: tbl_staff_allocation
pk_id fk_route_id fk_staff_id staff_type
1 27 13 Attendant
2 27 14 Driver
3 27 15 Conductor
I need the following data from the above tables, say for pk_route_id =27
Route_Name Vehicle_Number Vehicle_Type Driver_Id Attendant_Id Conductor
Route 2 REG1 Bus 13 14 15
I tried to write a part of the SQL as follows. I am stuck and not sure how to enhance it to get the required results.
SELECT a.route_code,a.route_name,a.route_description, tbl_b.fk_vehicle_id,tbl_c.fk_staff_id,tbl_c.staff_type, tbl_c.fk_route_id
FROM `list_routes` AS a
INNER JOIN tbl_route_vehicle_mgmt AS tbl_b
ON a.pk_route_id = tbl_b.fk_route_id
INNER JOIN tbl_staff_allocation AS tbl_c
ON a.pk_route_id = tbl_c.fk_route_id
where a.pk_route_id =27 AND (tbl_c.staff_type ="Driver" OR tbl_c.staff_type ="Conductot" OR tbl_c.staff_type ="Attendant" )
Can anyone please help me with the SQL to get the required data.

Answer 1

You should use several self join on tbl_staff_allocation
SELECT
a.route_code
,a.route_name
,a.route_description
,tbl_b.fk_vehicle_id
,tbl_c1.fk_route_id
,tbl_c1.fk_staff_id as Attendant_id
,tbl_c2.fk_staff_id as Driver_id
,tbl_c3.fk_staff_id as Conductor_id
FROM `list_routes` AS a
INNER JOIN tbl_route_vehicle_mgmt AS tbl_b ON a.pk_route_id = tbl_b.fk_route_id
INNER JOIN tbl_staff_allocation AS tbl_c1 ON a.pk_route_id = tbl_c1.fk_route_id and tbl_c1.staff_type ='Attendant'
INNER JOIN tbl_staff_allocation AS tbl_c2 ON a.pk_route_id = tbl_c2.fk_route_id and tbl_c.staff_type ='Driver'
INNER JOIN tbl_staff_allocation AS tbl_c3 ON a.pk_route_id = tbl_c3.fk_route_id and tbl_c.staff_type ='Conductor'
INNER JOIN list_vehicles AS d on d.pk_vehicle_id = tbl_b.fk_vehicle_id