Select data from one table base on selection from another table in SQL - sql

Question

I have these 3 table
First contain the item with price on given dates
2nd is the table of items
3rd is the table of dates in which we want to show the price of 2nd table item on every date
if duration is not available on first table it should be 0
with myTable ( item,startdate,enddate,price) as
(
select 'AAAA' ,'16-3-2020','19-3-2020','50' union all
select 'AAAA' ,'16-4-2020','19-4-2020','70' union all
select 'BBB' ,'16-3-2020','19-3-2020','20' union all
select 'BBB' ,'16-4-2020','19-4-2020','90' union all
select 'CCC' ,'16-3-2020','29-3-2020','45' union all
select 'CCC' ,'16-4-2020','19-4-2020','120'
)
select item,startdate,enddate,price from myTable
GO
with itemTable ( item) as
(
select 'AAAA' union all
select 'BBB' union all
select 'CCC'
)
select item from itemTable
GO
with DateTable ( dateItem) as
(
select '16-3-2020' union all
select '19-4-2020' union all
select '20-3-2020'
)
select dateItem from DateTable
GO
and my desire result should be like this (above is dynamic data)
with mydesireTable (item, [16-3-2020],[19-4-2020],[20-3-2020]) as
(
select 'AAAA' ,'50','70','0' union all ---0 as its not on above data in duration
select 'BBB' ,'20','90','0' union all
select 'CCC' ,'45','120','45'
)
select item, [16-3-2020],[19-4-2020],[20-3-2020] from mydesireTable
I am not sure what to search for :) as i want to write query for it which return my desire table as data ( or as in temporary table )

Answer 1

One of many ways to do this. This is a static crosstab. You need to list out all the columns explicitly (twice)
If your columns are dynamic, you need to use a dynamic crosstab. You should also consider doing this in your "presentation" layer, i.e. excel or whatever you are handing this over in.
You should consider what you want when something in mytable appears against a bucket twice (this solution will add the prices)
with myTable ( item,startdate,enddate,price) as
(
select 'AAAA' ,CAST('2020-03-16' AS DATE),CAST('2020-03-19' AS DATE),50 union all
select 'AAAA' ,'2020-04-16','2020-04-19',70 union all
select 'BBB' ,'2020-03-16','2020-03-19',20 union all
select 'BBB' ,'2020-04-16','2020-04-19',90 union all
select 'CCC' ,'2020-03-16','2020-03-29',45 union all
select 'CCC' ,'2020-04-16','2020-04-19',120
),
itemTable ( item) as
(
select 'AAAA' union all
select 'BBB' union all
select 'CCC'
)
,DateTable ( dateItem) as
(
select CAST('2020-03-16' AS DATE) union all
select '2020-04-19' union all
select '2020-03-20'
)
SELECT item,
[2020-03-16],[2020-04-19], [2020-03-20]
FROM
(
select item, dateitem, price from myTable
inner join datetable on datetable.dateItem between mytable.startdate and myTable.enddate
) As Src
PIVOT
(
SUM(price)
FOR
dateitem IN ([2020-03-16],[2020-03-20],[2020-04-19])
) as P

Answer 2

IF OBJECT_ID('tempdb..#myTable', 'U') IS NOT NULL
DROP TABLE #myTable;
IF OBJECT_ID('tempdb..#itemTable', 'U') IS NOT NULL
DROP TABLE #itemTable;
IF OBJECT_ID('tempdb..#DateTable', 'U') IS NOT NULL
DROP TABLE #DateTable;
CREATE TABLE #myTable (
item VARCHAR(MAX) NOT NULL,
startdate DATE NOT NULL,
enddate DATE NOT NULL,
price INT NOT NULL DEFAULT(0)
);
INSERT #myTable (item, startdate, enddate, price) VALUES
('AAAA' ,CAST('2020-03-16' AS DATE),CAST('2020-03-19' AS DATE),50),
('AAAA' ,'2020-04-16','2020-04-19',70),
('BBB' ,'2020-03-16','2020-03-19',20),
('BBB' ,'2020-04-16','2020-04-19',90),
('CCC' ,'2020-03-16','2020-03-29',45),
('CCC' ,'2020-04-16','2020-04-19',120)
CREATE TABLE #itemTable (
item VARCHAR(MAX) NOT NULL
)
INSERT #itemTable (item) VALUES
('AAAA'),
('BBB'),
('CCC')
CREATE TABLE #DateTable (
dateItem DATE NOT NULL
)
INSERT #DateTable (dateItem) VALUES
(CAST('2020-03-16' AS DATE)),
(CAST('2020-04-19' AS DATE)),
(CAST('2020-03-20' AS DATE)),
(CAST('2020-03-21' AS DATE)),
(CAST('2021-03-21' AS DATE)),
(CAST('2022-03-21' AS DATE))
Declare #DynamicCol nvarchar(max),#DynamicColNull nvarchar(max)
,#Sql nvarchar(max)
SELECT #DynamicColNull=STUFF((SELECT DISTINCT ', '+'ISNULL('+QUOTENAME(dateItem),','+'''0'''+') As '+QUOTENAME(dateItem)
FROM #DateTable FOR XML PATH ('')),1,2,'')
SELECT #DynamicCol=STUFF((SELECT DISTINCT ', '+QUOTENAME(dateItem) FROM #DateTable FOR XML PATH ('')),1,2,'')
SET #Sql='SELECT [item], '+#DynamicColNull+' From
(
select item, dateitem, price from #myTable
inner join #datetable on #datetable.dateItem between #mytable.startdate and #myTable.enddate
)
AS Src
PIVOT
(
SUM(price) FOR [dateitem] IN ('+#DynamicCol+')
)AS Pvt'
PRINT #Sql
EXEC(#Sql)