MySQL与更多的联接表执行联合

Question

As shown in below image I need to filter all the customers with and without loans .

Here is my mysql query :

SELECT
    cum.id,
    lhh.mst_customer_id,
    cum.first_name,
    cum.middle_name,
    cum.last_name,
    cum.name_ins,
    lhh.loan_amount,
    lhh.date_granted,
    lhh.loan_duration,
    lhh.status
FROM
    loan_management_app.trans_cus_has_loan_header lhh
LEFT JOIN
    loan_management_app.mst_customer cum
ON
    (
        lhh.mst_customer_id = cum.id)
UNION 
SELECT
    cum.id,
    lhh.mst_customer_id,
    cum.first_name,
    cum.middle_name,
    cum.last_name,
    cum.name_ins,
    lhh.loan_amount,
    lhh.date_granted,
    lhh.loan_duration,
    lhh.status
FROM
    loan_management_app.trans_cus_has_loan_header lhh
RIGHT JOIN
    loan_management_app.mst_customer cum
ON
    (
        lhh.mst_customer_id = cum.id)
INNER JOIN 
        loan_management_app.mst_loan lon
ON
    (
        lhh.mst_loan_id= lon.id)
INNER JOIN 
        loan_management_app.trans_loan_has_interest lhi
ON
        (lhi.mst_loan_id=lon.id)   
INNER JOIN loan_management_app.mst_interest mi
ON 
        (mi.id=lhi.mst_interest_id) ; 

But it still returns only the people with loans.Any help regarding this would be appreciable. Thanks in advance.

Answer 1

You're doing a LEFT JOIN with mst_customer ... so you're getting all loan_management even if don't have customer.

LEFT JOIN
    loan_management_app.mst_customer cum

Try to use RIGHT JOIN maybe:

RIGHT JOIN
    loan_management_app.mst_customer cum

Also, you can use that query, going from 'mst_customer' with all lefts joins. Something like that:

SELECT * FROM mst_customer mc 
LEFT JOIN trans_cus_has_loan_header tchl ON mc.id = tchl.mst_customer_id
LEFT JOIN mst_loan ml ON ml.id = tchl.mst_loan_id
LEFT JOIN trans_loan_has_interest tlhi ON tlhi.mst_loan_id = ml.id
LEFT JOIN mst_interest mi ON mi.id = tlhi.mst_interest_id

I hope this last one will work for you :-)