how can i remove subquery with a join?
SELECT distinct t."groupId" FROM "contacts" c
INNER JOIN
(
SELECT DISTINCT td.* FROM "groups" g
INNER JOIN
"territory" td
ON
td."groupId" = g.id
WHERE g."orgId" = 3
)
t
ON
ST_Intersects(t.points, c."geoPoint")
WHERE c.id = 33 and c."orgId" = 3
There is nothing wrong with a subquery, but you should get rid of the dreaded DISTINCT:
SELECT td."groupId"
FROM territory AS td
WHERE EXISTS (SELECT 1 FROM contacts AS c
WHERE ST_Intersects(td.points, c."geoPoint")
AND c.id = 33
AND c."orgId" = 3)
AND EXISTS (SELECT 1 FROM groups AS g
WHERE td."groupId" = g.id
AND g."orgId" = 3);
If you insist in having no subqueries, use
SELECT DISTINCT t."groupId"
FROM contacts c
INNER JOIN territory td
ON ST_Intersects(td.points, c."geoPoint")
INNER JOIN groups g
ON td."groupId" = g.id
WHERE g."orgId" = 3
AND c.id = 33
AND c."orgId" = 3;
If you need to make sure that the st_intersects function is only called for rows from territory that match the join with groups, you will have to use a subquery. There is no other way to force a join order.
Related
How can I write a linq to entities query that includes a group by and a having clause?
For example in SQL:
SELECT * FROM dbo.tblParent p
INNER JOIN
(
SELECT a.ID
FROM dbo.tblParent a
join dbo.tblChild c ON a.ID = c.FkParentID
WHERE a.ColValue = 167
GROUP BY A.ID
HAVING COUNT(c.ID) = 1
) t ON p.ID = t.ID
I found my own answer.
// this is far from pretty but it works as far as I can tell
Apps = (from x in context.tblParents
join t in (
from p in context.tblParents
join c in context.tblChilds
on p.ID equals c.FkParentID
where p.ColValue == 167
group c.ID by p.ID into grouped
where grouped.Count() == 1
select new { grouped.Key }) on x.ID equals t.Key
select x);
Im currently trying to combine 2 queries results in one.
These 2 queries has the same number of rows and are group by the same field but has different column.
This works :
SELECT Distinct
MAX(d.libelle) AS libelle_dpt,
MAX(d.code_dpt) AS code_dep,
MAX(r.libelle) AS libelle_region,
MAX(pd.pop_dep) AS nb_habitants,MAX(ls.nb_canton) AS nb_canton
FROM election_2015.commune c
LEFT JOIN (
SELECT MAX(c.code_canton) AS code_canton,Count(distinct c.code_canton) AS nb_canton
FROM election_2015.commune co
JOIN election_2015.departement d
ON co.code_dpt = d.code_dpt
JOIN election_2015.canton c
ON c.code_canton = co.code_canton
GROUP BY d.code_dpt
ORDER BY d.code_dpt ASC
) ls
ON ls.code_canton = c.code_canton
JOIN election_2015.departement d
ON d.code_dpt = c.code_dpt
JOIN election_2015.region r
ON d.code_region = r.code_region
JOIN election.popgent_all pd
ON pd.dep = d.code_dpt
GROUP BY d.code_dpt
But I was wondering if there is an other way to do this, maybe like an union but with rows?
Something like this (not working cause queries hasn't the same number of columns) :
SELECT Distinct
MAX(d.libelle) AS libelle_dpt,
MAX(d.id) AS id_dep,MAX(d.code_dpt) AS code_dep,
MAX(r.libelle) AS libelle_region,
MAX(pd.pop_dep) AS nb_habitants
FROM election_2015.commune c
LEFT JOIN election_2015.departement d
ON d.code_dpt = c.code_dpt
LEFT JOIN election_2015.region r
ON d.code_region = r.code_region
LEFT JOIN election.popgent_all pd
ON pd.dep = d.code_dpt
GROUP BY d.code_dpt
UNION
SELECT Count(distinct c.code_canton) AS nb_canton FROM election_2015.commune co
JOIN election_2015.departement d
ON co.code_dpt = d.code_dpt
JOIN election_2015.canton c
ON c.code_canton = co.code_canton
GROUP BY d.code_dpt
ORDER BY election_2015.departement.code_dpt ASC
Thanks for any help.
Alexandre
I have a following script to get the total unit but it gives me an error
Cannot perform an aggregate function on an expression containing an aggregate or a subquery.
Do I need to calculate SUM(ta.Qty) outside the main table?
SELECT
ta.ProductName
, SUM(ta.Total)
, SUM(SUM(ta.Qty) * ta.Unit)
FROM
tableA tA
INNER JOIN
tableB tB on tA.ID = tb.TableAID
INNER JOIN
tableC tc on ta.ID = tc.TableAID
INNER JOIN
tableD td on td.ID = tb.TableBID
GROUP BY
ta.ProductName
Here is a query in the AdventureWorks database that produces the same error (but might make some sense):
SELECT v.Name AS Vendor, SUM(SUM(p.ListPrice*d.OrderQty)+h.Freight)
FROM Production.Product p
INNER JOIN Purchasing.PurchaseOrderDetail d ON p.ProductID = d.ProductID
INNER JOIN Purchasing.PurchaseOrderHeader h ON h.PurchaseOrderID = d.PurchaseOrderID
INNER JOIN Purchasing.Vendor v ON v.BusinessEntityID = h.VendorID
GROUP BY v.Name
And here are two ways that I could rewrite that query to avoid the error:
SELECT v.Name AS Vendor, SUM(x.TotalAmount+h.Freight)
FROM (
SELECT PurchaseOrderID, SUM(p.ListPrice*d.OrderQty) AS TotalAmount
FROM Production.Product p
INNER JOIN Purchasing.PurchaseOrderDetail d ON p.ProductID = d.ProductID
GROUP BY PurchaseOrderID
) x
INNER JOIN Purchasing.PurchaseOrderHeader h ON h.PurchaseOrderID = x.PurchaseOrderID
INNER JOIN Purchasing.Vendor v ON v.BusinessEntityID = h.VendorID
GROUP BY v.Name
SELECT v.Name AS Vendor, SUM(x.TotalAmount+h.Freight)
FROM Purchasing.PurchaseOrderHeader h
INNER JOIN Purchasing.Vendor v ON v.BusinessEntityID = h.VendorID
CROSS APPLY (
SELECT SUM(p.ListPrice*d.OrderQty) AS TotalAmount
FROM Production.Product p
INNER JOIN Purchasing.PurchaseOrderDetail d ON p.ProductID = d.ProductID
WHERE d.PurchaseOrderID=h.PurchaseOrderID
) x
GROUP BY v.Name
The first query uses derived tables and the second one uses CROSS APPLY.
Can the following be rewritten to be more efficient?
I would use EXISTS if I didn't need fields from country but I do need those fields, and am not sure how to write this to make it more efficient.
SELECT distinct
p.ProvinceID,
p.Abbv as RegionCode,
p.name as RegionName,
cn.Code as CountryCode,
cn.Name as CountryName
FROM dbo.provinces AS p
INNER JOIN dbo.Countries AS cn ON p.CountryID = cn.CountryID
INNER JOIN dbo.Cities c on c.ProvinceID = p.ProvinceID
INNER JOIN dbo.Listings AS l ON l.CityID = c.CityID
WHERE l.IsActive = 1 AND l.IsApproved = 1
There are two things to note:
You're joining to dbo.Listings which results in many records, so you need to use DISTINCT (usually an expensive operator)
For any tables with columns not in the select you can move into an EXISTS (but the query planner effectively does this for you anyway)
So try this:
SELECT
p.ProvinceID,
p.Abbv as RegionCode,
p.name as RegionName,
cn.Code as CountryCode,
cn.Name as CountryName
FROM dbo.provinces AS p
INNER JOIN
dbo.Countries AS cn
ON p.CountryID = cn.CountryID
WHERE EXISTS (SELECT 1 FROM
dbo.Listings l
INNER JOIN dbo.Cities c
on l.CityID = c.CityID
WHERE c.ProvinceID = p.ProvinceID
AND l.IsActive = 1 AND l.IsApproved = 1
)
Check the query plans before and after - the query planner might be smart enough to do this anyway, but you have removed your distinct
The following will often perform even better by providing the optimizer more useful information:
SELECT
p.ProvinceID,
p.Abbv as RegionCode,
p.name as RegionName,
cn.Code as CountryCode,
cn.Name as CountryName
FROM dbo.provinces AS p
INNER JOIN
dbo.Countries AS cn
ON p.CountryID = cn.CountryID
INNER JOIN (
SELECT
p.ProvinceID
FROM
dbo.Listings l
INNER JOIN dbo.Cities c
on l.CityID = c.CityID
WHERE l.IsActive = 1 AND l.IsApproved = 1
GROUP BY
p.ProvinceID
) list
on list.ProvinceID = p.ProvinceID
Here's my query at the moment:
SELECT A.*
FROM A
LEFT JOIN B ON B.a_id = A.id
Now, suppose there is a table C which relates directly to B. What I'd like to do is to filter out the records of table B based on C - how do I do that? I've tried placing the filter in the WHERE section:
SELECT A.*
FROM A
LEFT JOIN B ON B.a_id = A.id
LEFT JOIN C ON B.c_id = C.id
WHERE C.id > 10
The problem is that the preceding queryalso filters out table A's results. How do I achieve the result that I want?
you need to put that filter in join :
SELECT *
FROM A
LEFT JOIN
(
SELECT B.*
FROM B
INNER JOIN C ON B.c_id = C.id AND C.id > 10
) AS B ON B.a_id = A.id
it will not filter out the A's results .