Merge many queries into one query to speed up - sql

Question

I have written a procedure that collects data from 4 tables and issues a general report for the day.
There are two similar SQL queries in the procedure, the execution time of each of which is more than 1 seconds, respectively, the procedure execution time is more than 2 seconds, can this be optimized?
CREATE PROCEDURE cv
#dt AS SMALLDATETIME
AS
SELECT
(SELECT ISNULL(SUM(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0)
FROM RCassa
WHERE DataRC = #dt) AS crMagPDP,
(SELECT ISNULL(SUM(SumPrice), 0) -
ISNULL(SUM(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0)
FROM RCassa
WHERE DataRC = #dt) AS crMag,
for browse
2 queries are shown just as an example, there are more subqueries.
Whole procedure:
SET ANSI_NULLS OFF
SET QUOTED_IDENTIFIER OFF
GO
CREATE PROCEDURE CV
#dt as SMALLDATETIME
AS
SELECT
(SELECT isnull(sum(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0)
FROM RCassa WHERE DataRC = #dt) as crMagPDP,
(SELECT ISNULL(sum(SumPrice), 0) - isnull(sum(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0)
FROM RCassa WHERE DataRC = #dt) AS crMag,
(SELECT ISNULL(SUM(What_Done.Price_Sp), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Sp >= 0 AND What_Done.Nal <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Out_Date)) = #dt
) as crParts,
(SELECT ISNULL(SUM(What_Done.Price_Total - ISNULL(What_Done.Price_Diag, 0)), 0)
FROM What_Done INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total > 0 AND What_Done.Nal <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Out_Date)) = #dt
) + (SELECT ISNULL(SUM(What_Done.Price_Diag), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total >= 0 AND What_Done.Nal <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Order_Date)) = #dt
) as crCassa,
(SELECT ISNULL(SUM(What_Done.Price_Diag), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total >= 0 AND What_Done.Nal <> 0 AND What_Done.BCard_IN <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Order_Date)) = #dt
) + (SELECT ISNULL(SUM(What_Done.Price_Total - ISNULL(What_Done.Price_Diag, 0)), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total >= 0 AND What_Done.Nal <> 0 AND What_Done.BCard_OUT <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Out_Date)) = #dt
) as crBCard,
(SELECT ISNULL(SUM(Summ), 0) FROM RevOrd WHERE Summ >= 0 AND Nal <> 0 AND DateOrd = #dt) as crNal,
(SELECT ISNULL(SUM(Summ), 0) FROM RevOrd WHERE Summ >= 0 AND Nal = 0 AND DateOrd = #dt) as crCard,
(SELECT ISNULL(Sum(SumTotal), 0) FROM LineOrders WHERE DataOut = #dt) as crLine,
(SELECT ISNULL(Sum(SumTotal), 0) FROM LineOrders WHERE DataOut = #dt and Dost <> 0) as crDostavka,
(SELECT ISNULL(SUM(What_Done.BCard_IN_Sum), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total >= 0 AND What_Done.Nal <> 0 AND What_Done.BCard_IN <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Order_Date)) = #dt
)+(SELECT ISNULL(SUM(What_Done.BCard_OUT_Sum), 0)
FROM What_Done
INNER JOIN ORDERS ON What_Done.uid = ORDERS.uid
WHERE What_Done.Price_Total >= 0 AND What_Done.Nal <> 0 AND What_Done.BCard_OUT <> 0
AND CONVERT(datetime, CONVERT(varchar(12), ORDERS.Out_Date)) = #dt
) as crBCardCorrect
for browse

Answer 1

Assuming the criteria for the sub-queries are identical and filter on DataRC = #dt and use the same data source RCassa, then you can simplify the query like this:
SELECT
isnull(sum(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0) as crMagPDP,
ISNULL(sum(SumPrice), 0) - isnull(sum(CASE WHEN PrePayDate IS NULL THEN '0' ELSE Price * Kvo END), 0) AS crMag,
...
FROM RCassa
WHERE DataRC = #dt

Answer 2

If the outer select is from other table[s] use APPLY
SELECT
isnull(t.crMagPDP, 0) crMagPDP,
isnull(t.crMag, 0) crMag,
..
FROM
..
OUTER APPLY (
SELECT
sum(CASE WHEN PrePayDate IS NULL THEN 0 ELSE Price * Kvo END) as crMagPDP,
sum(SumPrice) - sum(CASE WHEN PrePayDate IS NULL THEN 0 ELSE Price * Kvo END) AS crMag,
...
FROM RCassa
WHERE DataRC = #dt
) t