이 mysql 문 다시 쓰기

Question

이 문에 조인 (내부 또는 조인)을 사용하여 다른 테이블의 두 필드를 추가하려고합니다. 이것을 가장 잘 쓰는 방법은 무엇일까요? 나는 | a_l_code | dr_cr_code_inc | |----------|-------------------| | FA | DR |

select B.joint_account_numbers, 
    B.account_title, 
    SUM(case when A.dr_cr_action = 'CR' then A.amount * - 1 else A.amount end) as net_reduction 
from (
    select A.joint_account_number, 
     A.dr_cr_action, 
     A.amount 
    from mainaccount_a_2017 A 

    union all 

    select B.joint_account_number, 
     B.dr_cr_action, 
     B.amount 
    from mainaccount_b_2017 B 
    ) as A 
inner join chart_of_account B on A.joint_account_number = B.joint_account_numbers 
group by B.joint_account_numbers; 

Answer 1

Figured it out!  

    select B.joint_account_numbers, 
    B.account_title, C.a_l_code, C.dr_cr_code_inc, 
    SUM(case when A.dr_cr_action = 'CR' then A.amount * - 1 else A.amount end) as net_reduction 
    from (
    select A.joint_account_number, 
     A.dr_cr_action, 
     A.amount 
    from mainaccount_a_2017 A 

    union all 

    select B.joint_account_number, 
     B.dr_cr_action, 
     B.amount 
    from mainaccount_b_2017 B 
    ) as A 
    inner join chart_of_account B on A.joint_account_number = B.joint_account_numbers 
    inner join asset_liability_income_expenditure_tbl C on B.account_type = C.a_l_code 
    group by B.joint_account_numbers;`