Reduce multiple queries for reporting - mysql

Question

I am trying to make a query for a sales report, the code I have works excellent in the aspect that it returns the correct result, however I think it can be greatly improved since I am using multiple queries to generate the columns "Total_Productos", "Total_Servicios " and "Total", I have tried some ways to adjust it but I would like to hear some advice, I attach the code and the result it shows
SELECT f.numero, f.fecha, CONCAT(c.nombre, ' ', c.apellido) AS Cliente,
(SELECT GROUP_CONCAT(' x', CONVERT(fp2.cantidad, CHAR(10)), ' ', nombre) AS Product
FROM facturas_productos fp2
INNER JOIN productos ON productos.codigo = fp2.productos_codigo
WHERE fp2.facturas_numero = fp.facturas_numero) AS Productos,
TRUNCATE((SELECT SUM(fp2.cantidad * productos.precio_venta) AS T_Producto
FROM facturas_productos fp2
INNER JOIN productos ON productos.codigo = fp2.productos_codigo
WHERE fp2.facturas_numero = fp.facturas_numero), 2) AS Total_Productos,
(SELECT GROUP_CONCAT(CONCAT(' x', CONVERT(fs2.cantidad, CHAR(10)), ' ', nombre))
FROM facturas_servicios fs2
INNER JOIN servicios ON servicios.codigo = fs2.servicios_codigo
WHERE fs2.facturas_numero = fs.facturas_numero) AS Servicios,
TRUNCATE((SELECT SUM(fs2.cantidad * servicios.precio) AS T_Servicio
FROM facturas_servicios fs2
INNER JOIN servicios ON servicios.codigo = fs2.servicios_codigo
WHERE fs2.facturas_numero = fs.facturas_numero), 2) AS Total_Servicios,
TRUNCATE((SELECT SUM(fs2.cantidad * servicios.precio) AS T_Servicio
FROM facturas_servicios fs2
INNER JOIN servicios ON servicios.codigo = fs2.servicios_codigo
WHERE fs2.facturas_numero = fs.facturas_numero) +
(SELECT SUM(fp2.cantidad * productos.precio_venta) AS T_Producto
FROM facturas_productos fp2
INNER JOIN productos ON productos.codigo = fp2.productos_codigo
WHERE fp2.facturas_numero = fp.facturas_numero), 2) AS Total
FROM facturas f
INNER JOIN clientes c ON c.ID = f.clientes_ID
INNER JOIN facturas_productos fp ON fp.facturas_numero = f.numero
INNER JOIN facturas_servicios fs ON fs.facturas_numero = f.numero
WHERE f.fecha BETWEEN "2023-01-01" AND "2023-02-04"
GROUP BY f.numero, fp.facturas_numero, fs.facturas_numero, f.fecha, c.nombre, c.apellido
ORDER BY f.numero ASC;
Result from the query above:
I tried to take from the previous queries the values to calculate the total, however it gave me another unexpected result (generated an error/wrong value), i.e:
(SELECT GROUP_CONCAT(CONCAT(' x', CONVERT(fs2.cantidad, CHAR(10)), ' ', nombre)), fs2.cantidad * servicios.precio AS Monto
FROM facturas_servicios fs2
INNER JOIN servicios ON servicios.codigo = fs2.servicios_codigo
WHERE fs2.facturas_numero = fs.facturas_numero) AS Servicios
generates: Error Code: 1241. Operand should contain 1 column(s)
More info: I created the database from a diagram using forward engineer and not from scripts (still learning at university)
Database EER Diagram

Answer 1

If you are running MySQL >= 8.0.14, you can move your correlated sub-queries to lateral derived tables -
SELECT f.numero, f.fecha, CONCAT(c.nombre, ' ', c.apellido) AS Cliente,
fp.Productos, fp.Total_Productos,
fs.Servicios, fs.Total_Servicios,
IFNULL(fs.Total_Servicios, 0) + IFNULL(fp.Total_Productos, 0) AS Total
FROM facturas f
INNER JOIN clientes c ON c.ID = f.clientes_ID
LEFT JOIN LATERAL (
SELECT
GROUP_CONCAT('x', fp2.cantidad, ' ', nombre SEPARATOR ', ') AS Productos,
SUM(fp2.cantidad * productos.precio_venta) AS Total_Productos
FROM facturas_productos fp2
INNER JOIN productos ON productos.codigo = fp2.productos_codigo
WHERE fp2.facturas_numero = f.numero
) fp ON 1 = 1
LEFT JOIN LATERAL (
SELECT
GROUP_CONCAT('x', fs2.cantidad, ' ', nombre SEPARATOR ', ') AS Servicios,
SUM(fs2.cantidad * servicios.precio) AS Total_Servicios
FROM facturas_servicios fs2
INNER JOIN servicios ON servicios.codigo = fs2.servicios_codigo
WHERE fs2.facturas_numero = f.numero
) fs ON 1 = 1
WHERE f.fecha BETWEEN '2023-01-01' AND '2023-02-04'
ORDER BY f.numero ASC;
I have changed the joins to LEFT JOIN LATERAL as I assume it is possible for an invoice to contain products but not services, and vice versa.
An alternative approach, which does not require MySQL >= 8.0.14, is to aggregate all the products and services in their derived tables, instead of doing the lateral join -
SELECT f.numero, f.fecha, CONCAT(c.nombre, ' ', c.apellido) AS Cliente,
fp.Productos, fp.Total_Productos,
fs.Servicios, fs.Total_Servicios,
IFNULL(fs.Total_Servicios, 0) + IFNULL(fp.Total_Productos, 0) AS Total
FROM facturas f
INNER JOIN clientes c ON c.ID = f.clientes_ID
LEFT JOIN (
SELECT
fp.facturas_numero,
GROUP_CONCAT('x', fp.cantidad, ' ', nombre SEPARATOR ', ') AS Productos,
SUM(fp.cantidad * productos.precio_venta) AS Total_Productos
FROM facturas_productos fp
INNER JOIN productos ON productos.codigo = fp.productos_codigo
GROUP BY fp.facturas_numero
) fp ON f.numero = fp.facturas_numero
LEFT JOIN (
SELECT
fs.facturas_numero,
GROUP_CONCAT('x', fs.cantidad, ' ', nombre SEPARATOR ', ') AS Servicios,
SUM(fs.cantidad * servicios.precio) AS Total_Servicios
FROM facturas_servicios fs
INNER JOIN servicios ON servicios.codigo = fs.servicios_codigo
GROUP BY fs.facturas_numero
) fs ON f.numero = fs.facturas_numero
WHERE f.fecha BETWEEN '2023-01-01' AND '2023-02-04'
ORDER BY f.numero ASC;
This may be a little bit faster when retrieving all invoices but will probably be slower when retrieving a small subset of a large number of invoices.
And here's a db<>fiddle