Joining query sql server - sql-server

Question

I'm after some help please i'm new to SQL, can you help me join these to queries below I want all the data from the first query to be displayed and only the information that matches to be showed on the second query.
Part and subkey1 is the join
Thank you.
SELECT RHeads.[Document],
RLines.Part,
RHeads.Supp,
RHeads.DATETIME,
RLines.Unit,
RLines.CQty,
RHeads.POrder,
RHeads.Corder,
RHeads.Branch
FROM RLines
RIGHT OUTER JOIN RHeads ON RLines.[Document] = RHeads.[Document]
WHERE (RHeads.DATETIME >= DATEADD(MONTH, - 3, GETDATE()))
AND (RHeads.Corder = '02022076')
ORDER BY RHeads.DATETIME DESC;
SELECT Mvpr.Prefix,
Mvpr.SubKey1,
Mvpr.SubKey2,
Mvpr.A12
FROM Mvpr
INNER JOIN vwProduct ON Mvpr.SubKey1 = vwProduct.KeyCode
WHERE (Mvpr.Prefix = 'c');

Answer 1

Just stick both of these SQL statements into their own subquery (using parantheses) and give each subquery an alias so we can refer to it's result set in the main query:
SELECT
t1.*,
t2.*
FROM
(
SELECT RHeads.[Document],
RLines.Part,
RHeads.Supp,
RHeads.DATETIME,
RLines.Unit,
RLines.CQty,
RHeads.POrder,
RHeads.Corder,
RHeads.Branch
FROM RLines
RIGHT OUTER JOIN RHeads ON RLines.[Document] = RHeads.[Document]
WHERE (RHeads.DATETIME >= DATEADD(MONTH, - 3, GETDATE()))
AND (RHeads.Corder = '02022076')
) t1
LEFT OUTER JOIN
(
SELECT Mvpr.Prefix,
Mvpr.SubKey1,
Mvpr.SubKey2,
Mvpr.A12
FROM Mvpr
INNER JOIN vwProduct ON Mvpr.SubKey1 = vwProduct.KeyCode
WHERE (Mvpr.Prefix = 'c')
) t2 ON t1.Part = t2.SubKey1
ORDER BY t1.DATETIME DESC;
We're using a LEFT OUTER JOIN to get all of the records from t1 (first query) and only those records that match from t2 (second query).
Also I have moved the ORDER BY clause to the main query as you can't ORDER inside of a subquery (and even if you were allowed to, the ordering would be lost after the join so it would be superfluous).
Since you aren't doing any aggregating here, you could probably rewrite this without the subquery too.
I've made some assumptions about your data, but perhaps something like:
SELECT RHeads.[Document],
RLines.Part,
RHeads.Supp,
RHeads.DATETIME,
RLines.Unit,
RLines.CQty,
RHeads.POrder,
RHeads.Corder,
RHeads.Branch,
Mvpr.Prefix,
Mvpr.SubKey1,
Mvpr.SubKey2,
Mvpr.A12
FROM RHeads
LEFT OUTER JOIN RLines
ON RLines.[Document] = RHeads.[Document]
LEFT OUTER JOIN vwProduct
ON Mvpr.SubKey1 = vwProduct.KeyCode
LEFT OUTER JOIN Mvpr
ON vwProduct.KeyCode = Mvpr.Subkey1
AND Mvpr.Prefix = 'c'
WHERE
RHeads.DATETIME >= DATEADD(MONTH, - 3, GETDATE())
AND RHeads.Corder = '02022076'

Answer 2

If you want to maintain the granularity of the 1st query put them in CTEs and check existence:
;WITH Q1 AS(
SELECT RHeads.[Document],
RLines.Part,
RHeads.Supp,
RHeads.DATETIME,
RLines.Unit,
RLines.CQty,
RHeads.POrder,
RHeads.Corder,
RHeads.Branch
FROM RLines
RIGHT OUTER JOIN RHeads ON RLines.[Document] = RHeads.[Document]
WHERE (RHeads.DATETIME >= DATEADD(MONTH, - 3, GETDATE()))
AND (RHeads.Corder = '02022076')
), Q2 AS (
SELECT Mvpr.Prefix,
Mvpr.SubKey1,
Mvpr.SubKey2,
Mvpr.A12
FROM Mvpr
INNER JOIN vwProduct ON Mvpr.SubKey1 = vwProduct.KeyCode
WHERE (Mvpr.Prefix = 'c')
)
SELECT q1.*
FROM Q1 q1
WHERE EXISTS(
SELECT *
FROM Q2 q2
WHERE q1.Part = q2.SubKey1
)
ORDER BY q1.DATETIME DESC