How to check intersection of subqueries in query? - sql

Question

I have the next query:
SELECT c.client_code, a.account_num, m.account_close_date, u.uso, m.product_name
FROM accounts a INNER JOIN Clients c ON c.id = a.client_id INNER JOIN
Uso u ON c.uso_id = u.uso_id INNER JOIN Magazine m ON a.account_id = m.account_id
and I need to compare product_name with input parameter.
product_name and input parameter #s are comma-delimited strings.
I use next split function:
ALTER FUNCTION [dbo].[Split]
(
#s VARCHAR(max),
#split CHAR(1)
)
RETURNS #temptable TABLE (items VARCHAR(MAX))
AS
BEGIN
DECLARE #x XML
SELECT #x = CONVERT(xml,'<root><s>' + REPLACE(#s,#split,'</s><s>') + '</s></root>');
INSERT INTO #temptable
SELECT [Value] = T.c.value('.','varchar(20)')
FROM #X.nodes('/root/s') T(c);
RETURN
END;
I think that I need to check the intersection of tables, which I will receive after split of product_name and after split of input parameter. I trid to do this:
WHERE (select * from dbo.Split(m.product_name, ';')
INTERSECT select * from dbo.Split('product1;product2',';'))
is not null
But it does not work quite right. Please, help me.

Answer 1

INTERSECT requires the same column output and is used like UNION or EXCEPT: not in the WHERE clause
Just JOIN onto the udf
...
INNER JOIN
Magazine m ON a.account_id = m.account_id
INNER JOIN
dbo.Split(#parameter, ';') CSV ON m.productname = CSV.items
If you need to split m.productname, if you can't fix the design, use CROSS APPLY
...
INNER JOIN
Magazine m ON a.account_id = m.account_id
CROSS APPLY
dbo.Split(m.productname, ';') WTF
INNER JOIN
dbo.Split(#parameter, ';') CSV ON WTF.items = CSV.items
However, JOIN and INTERSECT give different results if #parameter has duplicated values. Add a DISTINCT to the UDF for example to get around this. Or change the udf JOIN into EXISTS