四個表格之間的左連接

Question

SELECT * FROM 
    mtc_employee_master EB, 
    mtc_employee_education_master EE, 
    mtc_employee_experience_master EEXP, 
    mtc_employee_salary_master ES 
WHERE 
    EB.id=16 AND 
    EE.emp_tbl_id=EB.id AND 
    EEXP.emp_tbl_id=EB.id AND 
    ES.emp_tbl_id=EB.id 

如果數據在所有表格中可用，上述查詢可以正常工作。現在，我想從mtc_employee_master中提取哪些輸出記錄，因爲表格包含記錄爲必填表格，而其他記錄不包含記錄。使用左加入我已經成功了兩個表

SELECT * FROM 
    mtc_employee_master EB 
LEFT JOIN 
    mtc_employee_education_master EE 
ON 
    EB.`id` = EE.`emp_tbl_id` 
WHERE 
    EB.id=16 

而是停留在加盟的所有four..please給你輸入

Answer 1

試試這個：

SELECT * FROM mtc_employee_master EB 
    left join mtc_employee_education_master EE on EE.emp_tbl_id=EB.id 
    left join mtc_employee_experience_master EEXP on EEXP.emp_tbl_id=EB.id 
    left join mtc_employee_salary_master ES on ES.emp_tbl_id =EB.id 
    WHERE EB.id=16 

Answer 2

做這樣的（EDITED） ：

SELECT EB.* 
FROM mtc_employee_master EB left join 
(SELECT EE.id var FROM mtc_employee_education_master EE 
    join mtc_employee_experience_master EEXP on EE.id=EEXP.id 
    join mtc_employee_salary_master ES 
    on ES.id=EEXP.id) temp 
    on EB.id= temp.var 
where EB.id=16; 

Answer 3

SELECT * FROM 
    mtc_employee_master EB, 
    mtc_employee_education_master EE, 
    mtc_employee_experience_master EEXP, 
    mtc_employee_salary_master ES 
WHERE 
    EB.id=16 AND 
    IFNULL(EE.emp_tbl_id,0)IN(EB.id,0) AND 
    IFNULL(EEXP.emp_tbl_id,0)IN(EB.id,0) AND 
    IFNULL(ES.emp_tbl_id,0)IN(EB.id,0)