Пример работы с SQL запросами:
определение объёмов и стоимости услуг по передаче электроэнергии

SELECT
row_number() OVER(ORDER BY ZZ.ID) AS num,
ZZ.ID AS ID,
ZZ.client AS client,
ZZ.filial AS filial,
ZZ.res AS res,
ZZ.region AS region
FROM
(
SELECT DISTINCT
c.`id` AS ID,
c.name AS client,
dvf.div_name AS filial,
dv.div_name AS res,
rg.reg AS region
FROM `client` c
LEFT JOIN `object` o ON `o`.`id_client` = `c`.`id`
LEFT JOIN `div-reg` dvrg ON `dvrg`.`id` = `o`.`id_div-reg`
LEFT JOIN `division` dv ON `dv`.`id` = `dvrg`.`id_division`
LEFT JOIN `division` dvf ON `dvf`.`id` = `dv`.`id_parent`
LEFT JOIN `region` rg ON `rg`.`id` = `dvrg`.`id_region`
) ZZ
WHERE ZZ.client LIKE '%ФСК%'
ORDER BY ZZ.ID ASC

SELECT
row_number() OVER(ORDER BY ZZ.id) AS num,
ZZ.id AS id,
ZZ.object_name AS object_name,
ZZ.group_name AS group_name,
ZZ.client_name AS client_name,
ZZ.res AS res,
ZZ.filial AS filial,
ZZ.region AS region
FROM
(
SELECT
o.id AS id,
o.name AS object_name,
gr.name AS group_name,
cl.name AS client_name,
dvr.div_name AS res,
dvf.div_name AS filial,
r.reg AS region
FROM `object` o
LEFT JOIN `group` gr ON `gr`.`id` = `o`.`id_group`
LEFT JOIN `client` cl ON cl.`id` = `o`.`id_client`
LEFT JOIN `div-reg` dvrg ON `dvrg`.`id` = `o`.`id_div-reg`
LEFT JOIN `division` dvr ON `dvr`.`id` = `dvrg`.`id_division`
LEFT JOIN `region` r ON `r`.`id` = `dvrg`.`id_region`
LEFT JOIN `division` dvf ON dvf.id = dvr.id_parent
) ZZ

SELECT
row_number() OVER(ORDER BY ZZ.reg_id, ZZ.gr_id, ZZ.volt_id) AS num,
ZZ.reg_name,
ZZ.gr_name,
ZZ.volt_name,
ZZ.data1,
ZZ.data2,
ZZ.tarif
FROM (
SELECT DISTINCT
r.id AS reg_id,
r.reg AS reg_name,
g.id AS gr_id,
g.name AS gr_name,
IF(p.id_volt IS null,0,v.id) AS volt_id,
IF(p.id_volt IS null,'-', v.name) AS volt_name,
p.data1 AS data1,
p.data2 AS data2,
p.tarif
FROM `prise` p
JOIN `group` g ON `g`.`id`=`p`.`id_group`
JOIN `region` r ON `r`.`id` = `p`.`id_region`
JOIN `volt` v ON `v`.`id` = `p`.`id_volt` OR `p`.`id_volt` IS NULL
)ZZ
ORDER BY ZZ.reg_id ASC, ZZ.gr_id ASC, ZZ.volt_id ASC

SELECT
Z.reg,
Z.filial,
Z.res,
Z.volt_name,
IFNULL(SUM(Z.priem),0) AS priem,
IFNULL(SUM(Z.po_so),0)+IFNULL(SUM(Z.po_org),0)+IFNULL(SUM(Z.po_nas),0) AS po_vsg,
IFNULL(SUM(Z.po_so),0) AS po_so,
IFNULL(SUM(Z.po_org),0) AS po_org,
IFNULL(SUM(Z.po_nas),0) AS po_nas
FROM (
SELECT
ZZ.dt AS dt,
ZZ.reg AS reg,
ZZ.filial AS filial,
ZZ.res AS res,
ZZ.volt_name AS volt_name,
ZZ.volt_id AS volt_id,
SUM(CASE WHEN ZZ.group_id = 1 THEN ZZ.val END) AS priem,
SUM(CASE WHEN ZZ.group_id = 2 THEN ZZ.val END) AS po_so,
SUM(CASE WHEN ZZ.group_id = 3 THEN ZZ.val END) AS po_org,
SUM(CASE WHEN ZZ.group_id = 4 THEN ZZ.val END) AS po_nas
FROM (
SELECT
s.date AS dt,
r.reg AS reg,
df.div_name AS filial,
d.div_name AS res,
g.`name` AS group_name,
g.`id` AS group_id,
v.name AS volt_name,
v.id AS volt_id,
s.value AS val
FROM `sales` s
LEFT JOIN `object` o ON `o`.`id` = s.id_object
LEFT JOIN `div-reg`dvrg ON dvrg.`id` = o.`id_div-reg`
LEFT JOIN `region` r ON `r`.`id` = `dvrg`.`id_region`
LEFT JOIN `division` d ON `d`.`id` = `dvrg`.`id_division`
LEFT JOIN `division` df ON `df`.`id` = `d`.`id_parent`
LEFT JOIN `volt` v ON `v`.`id` = `s`.`id_volt`
LEFT JOIN `group` g ON `g`.`id` = `o`.`id_group`
WHERE s.date BETWEEN '2023-12-01' AND '2023-12-31'
) ZZ
WHERE ZZ.res LIKE '%Владимирский%'
GROUP BY ZZ.dt, ZZ.reg, ZZ.filial, ZZ.res, ZZ.volt_name
) Z
GROUP BY Z.reg, Z.filial, Z.res, Z.volt_name
ORDER BY Z.reg, Z.filial, Z.res, Z.volt_id

SELECT
Z3.dt AS dt,
Z3.id_filial AS id_filial,
Z3.filial_name AS filial,
Z3.id_reg AS id_reg,
Z3.reg_name AS reg_name,
Z3.id_group AS id_group,
Z3.group_name AS group_name,
Z3.id_volt AS id_volt,
Z3.volt_name AS volt_name,
IFNULL(p.tarif, 0) AS tarif,
Z3.poteri AS poteri,
IF(Z3.id_group=5, SUM(Z3.poteri) OVER(PARTITION BY CONCAT(Z3.dt,'',Z3.id_reg)), Z3.val) AS val,
ROUND(IFNULL(p.tarif, 0)*IF(Z3.id_group=5, SUM(Z3.poteri) OVER(PARTITION BY CONCAT(Z3.dt,'',Z3.id_reg)), Z3.val),2) AS cost
FROM
(
SELECT
Z2.id_filial AS id_filial,
Z2.filial_name AS filial_name,
Z2.id_reg AS id_reg,
Z2.reg_name AS reg_name,
Z2.id_group AS id_group,
Z2.group_name AS group_name,
Z2.id_volt AS id_volt,
IFNULL(Z2.volt_name, '-') AS volt_name,
Z2.dt AS dt,
Z2.val AS val,
Z2.poteri AS poteri
FROM
(
SELECT
Z1.id_filial AS id_filial,
Z1.filial_name AS filial_name,
Z1.id_reg AS id_reg,
Z1.reg_name AS reg_name,
Z1.id_group AS id_group,
Z1.group_name AS group_name,
Z1.id_volt AS id_volt,
Z1.volt_name AS volt_name,
Z1.dt AS dt,
SUM(Z1.val) AS val,
SUM(Z1.poteri) AS poteri
FROM
(
SELECT
s.id AS id_sales,
df.id AS id_filial,
df.div_name AS filial_name,
dr.id AS id_res,
dr.div_name AS res_name,
r.id AS id_reg,
r.reg AS reg_name,
g.id AS id_group,
g.name AS group_name,
IF(g.id = 3, s.id_volt, NULL) AS id_volt,
IF(g.id = 3, v.name, NULL) AS volt_name,
s.date AS dt,
s.value AS val,
IF(g.id = 1, s.value, - s.value) AS poteri
FROM
`sales` s
JOIN `object` o ON
`o`.`id` = `s`.`id_object`
JOIN `div-reg` dvrg ON
`dvrg`.`id` = `o`.`id_div-reg`
JOIN `division` dr ON
`dr`.`id` = `dvrg`.`id_division`
JOIN `division` df ON
`df`.`id` = `dr`.`id_parent`
JOIN `region` r ON
`r`.`id` = `dvrg`.`id_region`
JOIN `volt` v ON
`v`.`id` = `s`.`id_volt`
JOIN `group` g ON
`g`.`id` = `o`.`id_group`
) Z1
GROUP BY
Z1.id_filial,
Z1.filial_name,
Z1.id_reg,
Z1.reg_name,
Z1.id_group,
Z1.group_name,
Z1.id_volt,
Z1.volt_name,
Z1.dt
) Z2
UNION
SELECT
`df`.`id` AS id_filial,
`df`.`div_name` AS filial_name,
`r`.`id` AS id_reg,
`r`.`reg` AS reg_name,
`g`.`id` AS id_group,
`g`.`name` AS group_name,
NULL AS id_volt,
'-' AS volt_name,
`p`.`data2` - INTERVAL 1 DAY AS dt,
0 AS val,
0 AS poteri
FROM
`price` p
JOIN `group` g ON
`g`.`id` = `p`.`id_group` AND `g`.`id` = 5
JOIN `region` r ON
`r`.`id` = `p`.`id_region`
JOIN `div-reg` dvrg ON
`dvrg`.`id_region` = `p`.`id_region`
JOIN `division` dr ON
`dr`.`id` = `dvrg`.`id_division`
JOIN `division` df ON
`df`.`id` = `dr`.`id_parent`
) Z3
LEFT JOIN `price` p ON
`p`.`id_region` = Z3.id_reg AND `p`.`id_group` = Z3.id_group AND IF(
`p`.`id_volt` IS NULL,
TRUE,
`p`.`id_volt` = Z3.id_volt
) AND Z3.dt BETWEEN `p`.`data1` AND `p`.`data2`
ORDER BY
Z3.dt,
Z3.id_filial,
Z3.id_reg,
Z3.id_group,
Z3.id_volt