Question

My database has a structure like this:

‘Movimientos’ table keeps records of all charges and payments of my system.
‘Cargos’ table keeps some metadata of each charge on ‘Movimientos’ and ‘Abonos’ table keeps some metadata of each payment on ‘Movimientos’.

How do I write a query which sum all records in ‘Movimientos’ where ‘Abonos.tipo_abono’ and ‘Cargos.tipo_cargo’ have some criteria?

I have a query that already sum ‘Movimientos’ but I can’t add the part where ‘Abonos’ and ‘Cargos’ tables add more criteria.

SELECT SUM(M.monto) as monto, SUM(M.interes) as interes, SUM(M.iva) as iva, SUM(M.capital) as capital
                FROM movimientos AS M
                JOIN acreditados AS A ON A.id_acreditado = M.id_acreditado
                JOIN creditos AS C ON C.id_credito = A.id_credito
                WHERE  C.id_credito = 29

Let’s say I want modify the last query to just sum records where ‘Abono.tipo_abono’=1 and ‘Cargos.tipo_cargo’=1, how do I do it?

Answer 1

If your relationships are one-to-one, you can just join the tables in and filter by your criteria. If related records are always present, make it an inner join. If the related tables may not have records, it should be a LEFT OUTER JOIN with the criteria specified in the JOIN rather than the WHERE.

SELECT SUM(M.monto) as monto,
    SUM(M.interes) as interes,
    SUM(M.iva) as iva,
    SUM(M.capital) as capital
FROM movimientos AS M
JOIN acreditados AS A ON A.id_acreditado = M.id_acreditado
JOIN creditos AS C ON C.id_credito = A.id_credito
LEFT OUTER JOIN Abonos AS AB on AB.id_movimiento = M.id_movimiento AND AB.tipo_abono = 1
LEFT OUTER JOIN Cargos AS CG on CG.id_movimiento = M.id_movimiento AND CG.tipo_cargo = 1
WHERE  C.id_credito = 29

However, if your relationships are many-to-one, this will affect your sum by including multiple movimientos rows. Use an EXISTS clause instead:

SELECT SUM(M.monto) as monto,
    SUM(M.interes) as interes,
    SUM(M.iva) as iva,
    SUM(M.capital) as capital
FROM movimientos AS M
JOIN acreditados AS A ON A.id_acreditado = M.id_acreditado
JOIN creditos AS C ON C.id_credito = A.id_credito
WHERE  C.id_credito = 29
AND EXISTS (SELECT 1
    FROM Abonos AB
    WHERE AB.id_movimiento = M.id_movimiento
    AND tipo_abono = 1
)
AND EXISTS (SELECT 1
    FROM Cargos CG
    WHERE CG.id_movimiento = M.id_movimiento
    AND tipo_cargo = 1
)