关于php：如何连接四个表来显示具体数据

equipment_id   equipment_name
———–    ————–
1              Motor Cycle
2              Private Car

project_id    project_name
———-    ————
1              xyz trading
2              abc private ltd

rental_id      project_id    equipment_id   Rental_date
———————————————————
1                 2                 1         12/10/2018
2                 2                2          15/09/2018
3                 1                2          20/10/2018

remove_id      project_id    equipment_id   removal_date
———————————————————
1                 2                 1         null
2                 2                2         14/10/18

these are my table, now i want to display data of single equipment (eg: equipment no 2) in which project this equipment ran, when was the rental date and when was the removal date from a project.

    SN   Project Name      Rental date       Removal date
    —  ————      ———–       ————
    1    ABC pvt Ltd        15/09/2018       14/10/2018
    2    xyz trading        20/10/2018         Null

SELECT
(@cnt := @cnt + 1) AS SN,
PROJECT.project_name AS Project Name,
RENTAL.Rental_date AS Rental date,
REMOVAL.removal_date AS Removal date
FROM
rental_table RENTAL
LEFT JOIN project_table PROJECT ON (RENTAL.project_id = PROJECT.id)
LEFT JOIN equipment_table EQUIPMENT ON (RENTAL.equipment_id = EQUIPMENT.id)
LEFT JOIN removal_table REMOVAL ON (PROJECT.id = REMOVAL.project_id AND PROJECT.equipment_id = REMOVAL.equipment_id)
WHERE
EQUIPMENT.id = 2;