I need use CTE with two tables - sql

Question

I have 2 tables and I need to use a CTE.
I need a set of rows of Table_2 on rows from Table_1, such that dActiveDate is biggest in table_1, and table_1.dActiveDate <= table_2.dDateFactor for table_1.dcidKala = table_2.dcidKala.
CREATE TABLE #Table_1
(
dcidKala INT,
dcPercentDiscount FLOAT,
dActiveDate DATE
)
CREATE TABLE #Table_2
(
dcRow INT,
dcidKala INT,
dcNum FLOAT,
dDateFactor DATE
)
INSERT INTO #Table_1
(
dcidKala,
dcPercentDiscount,
dActiveDate
)
VALUES
(109,10,'2017-08-23' ),
(109, 15, '2017-10-12'),
(100, 20, '2017-01-20'),
(102, 20, '2017-01-20')
INSERT INTO #Table_2
(
dcRow,
dcidKala,
dcNum,
dDateFactor
)
VALUES
( 1,109,1, '2017-10-05' ),
(2, 109, 2, '2017-10-07'),
(3, 109, 1, '2017-10-14'),
(4, 109, 5, '2017-10-19'),
(5, 100, 2, '2017-01-25')
;WITH cte AS
(
SELECT th.dcPercentDiscount,
tb.dcRow,
ROW_NUMBER() OVER(PARTITION BY th.dcidKala, tb.dcRow ORDER BY th.dActiveDate) AS
rn
FROM #Table_1 th
INNER JOIN #Table_2 tb
ON tb.dcidKala = th.dcidKala
AND tb.dDateFactor >= th.dActiveDate
)
SELECT *
FROM #Table_2 t2
LEFT JOIN cte t3
ON t2.dcRow = t3.dcRow
AND t3.rn = 1
DROP TABLE [#Table_1]
DROP TABLE [#Table_2]
--result myCode is:
--1 109 1 2017-10-05 10 1 1
--2 109 2 2017-10-07 10 2 1
--3 109 1 2017-10-14 10 3 1
--4 109 5 2017-10-19 10 4 1
--5 100 2 2017-01-25 20 5 1
--Rows 3 and Rows 4 is wrong
--i need this result :
-- on Result From table_1 on table_2
--1 109 1 2017-10-05 10 1 1
--2 109 2 2017-10-07 10 2 1
--3 109 1 2017-10-14 15 3 1
--4 109 5 2017-10-19 15 4 1
--5 100 2 2017-01-25 20 5 1
For each row in table_2 just one result from table_1 that is biggest on
dActiveDate and smaller dDateFactor
Please help me
thank you

Answer 1

You can use this.
;WITH cte AS
(
SELECT
th.dcPercentDiscount, tb.dcRow,
ROW_NUMBER() OVER(PARTITION BY th.dcidKala, tb.dcRow ORDER BY th.dActiveDate DESC) AS rn
FROM
Table_1 th
INNER JOIN
Table_2 tb ON tb.dcidKala = th.dcidKala
AND tb.dDateFactor >= th.dActiveDate
)
SELECT *
FROM Table_2 t2
LEFT JOIN cte t3 ON t2.dcRow = t3.dcRow and t3.rn=1

Answer 2

CREATE TABLE #Table_1 (dcidKala INT,
dcPercentDiscount FLOAT,
dActiveDate DATE)
CREATE TABLE #Table_2 (dcRow INT,
dcidKala INT,
dcNum FLOAT,
dDateFactor DATE)
INSERT INTO #Table_1 (dcidKala,
dcPercentDiscount,
dActiveDate)
VALUES (100, 10, '2017-01-01'),
(101, 15, '2017-01-02'),
(100, 20, '2017-01-20'),
(102, 20, '2017-01-20')
INSERT INTO #Table_2 (dcRow,
dcidKala,
dcNum,
dDateFactor)
VALUES (1, 100, 1, '2017-01-05'),
(2, 100, 2, '2017-01-09'),
(3, 101, 1, '2017-01-01'),
(4, 101, 5, '2017-01-20'),
(5, 100, 2, '2017-01-25')
SELECT *
FROM [#Table_2] AS [t2]
CROSS APPLY ( SELECT TOP 1 *
FROM ( SELECT TOP 1 [t1].[dcidKala],
[t1].[dcPercentDiscount],
[t1].[dActiveDate]
FROM [#Table_1] AS [t1]
WHERE [t1].[dcidKala] = [t2].[dcidKala]
AND [t2].[dDateFactor] >= [t1].[dActiveDate]
ORDER BY [t1].[dActiveDate] DESC
UNION ALL
SELECT NULL,
NULL,
NULL) t3
ORDER BY CASE
WHEN [t2].[dcidKala] IS NOT NULL THEN 0
ELSE 1
END) AS t1
DROP TABLE [#Table_1]
DROP TABLE [#Table_2]