IS it possible to return the table of a With-Statement from an inline-table valued function?
my With-Statement looks like this
WITH ret AS(
SELECT t.ID
FROM SelfReferencingTable
WHERE ID = #PartnerID
UNION ALL
SELECT t.ID
FROM (SelfReferencingTable) t INNER JOIN
ret r ON t.ParentID = r.ID
)
Yes, you can. You just have to place the common table expression (what you refer to as a WITH statement) in the appropriate place:
create function TT()
RETURNS TABLE
AS
RETURN (With Aardvark as (select * from sysobjects) --TODO - Remove *, use column names
select * from Aardvark)
;
Related
I have a rather complex plpgsql stored procedure and I need to select from multiple tables and insert as well.
This is part of what I currently have.
BEGIN
RETURN query
SELECT domains.id, webpages.id as page_id ...
FROM domains
LEFT JOIN domain_settings
ON domain_settings.domain_id = domains.id
RIGHT JOIN webpages
ON webpages.domain_id = domains.id
LEFT JOIN subscriptions
ON webpages.id = subscriptions.page_id
AND subscriptions.user_id = query_user_id
AND subscriptions.comment_id IS NULL
WHERE domains.domain_address = query_domain_url
IF NOT FOUND THEN ...
END;
$$ language plpgsql;
Now, I would like add an insert query into another table using certain values from the return query before the 'if not found then' statement:
INSERT INTO page_visits (domain_id, page_id)
SELECT id, page_id FROM ?? (return query statement)
And after the insert, I want to return the initial return query values. How do I go about doing this? I tried using WITH AS statements, but I can't seem to get it to work
A set-returning PL/pgSQL function builds the return stack while processing the function body. There is no way to access that return stack from within the same function. You could nest the function. Or use a temporary table.
But using a CTE is probably the simplest way for the cas at hand. Going out on a limb, you may be looking for something like this:
CREATE OR REPLACE FUNCTION demo(query_user_id int, query_domain_url text)
RETURNS TABLE (c1 int, c2 int)
LANGUAGE plpgsql AS
$func$
BEGIN
RETURN QUERY
WITH sel AS (
SELECT d.id, w.id as page_id ...
FROM webpages w
JOIN domains d ON d.id = w.domain_id
LEFT JOIN domain_settings ds ON ds.domain_id = d.id
LEFT JOIN subscriptions s ON s.page_id = w.id
AND s.user_id = query_user_id -- origin?
AND s.comment_id IS NULL
WHERE d.domain_address = query_domain_url -- origin?
)
, ins AS (
INSERT INTO tbl (col1, col2)
SELECT main.id, sel.page_id
FROM (SELECT 'foo') AS main(id)
LEFT JOIN sel USING (id) -- LEFT JOIN ?
)
TABLE sel;
IF NOT FOUND THEN
-- do something
END IF;
END
$func$;
Remember, if the transaction does not commit successfully, the INSERT is also rolled back.
The final TABLE sel is just short syntax for SELECT * FROM sel. See:
Is there a shortcut for SELECT * FROM?
I have a query that is using a temp table to insert some data then another select from to extract distinct results. That query by it self was fine but now with entity-framework it is causing all kinds of unexpected errors at the wrong time.
Is there any way I can rewrite the query not to use a temp table? When this is converted into a stored procedure and in entity framework the result set is of type int which throws an error:
Could not find an implementation of the query pattern Select not found.
Here is the query
Drop Table IF EXISTS #Temp
SELECT
a.ReceiverID,
a.AntennaID,
a.AntennaName into #Temp
FROM RFIDReceiverAntenna a
full join Station b ON (a.ReceiverID = b.ReceiverID) and (a.AntennaID = b.AntennaID)
where (a.ReceiverID is NULL or b.ReceiverID is NULL)
and (a.AntennaID IS NULL or b.antennaID is NULL)
select distinct r.ReceiverID, r.ReceiverName, r.receiverdescription
from RFIDReceiver r
inner join #Temp t on r.ReceiverID = t.ReceiverID;
No need for anything fancy, you can just replace the reference to #temp with an inner sub-query containing the query that generates #temp e.g.
select distinct r.ReceiverID, r.ReceiverName, r.receiverdescription
from RFIDReceiver r
inner join (
select
a.ReceiverID,
a.AntennaID,
a.AntennaName
from RFIDReceiverAntenna a
full join Station b ON (a.ReceiverID = b.ReceiverID) and (a.AntennaID = b.AntennaID)
where (a.ReceiverID is NULL or b.ReceiverID is NULL)
and (a.AntennaID IS NULL or b.antennaID is NULL)
) t on r.ReceiverID = t.ReceiverID;
PS: I haven't made any effort to improve the query overall like Gordon has but do consider his suggestions.
First, a full join makes no sense in the first query. You are selecting only columns from the first table, so you need that.
Second, you can use a CTE.
Third, you should be able to get rid of the SELECT DISTINCT by using an EXISTS condition.
I would suggest:
WITH ra AS (
SELECT ra.*
FROM RFIDReceiverAntenna ra
Station s
ON s.ReceiverID = ra.ReceiverID AND
s.AntennaID = ra.AntennaID)
WHERE s.ReceiverID is NULL
)
SELECT r.ReceiverID, r.ReceiverName, r.receiverdescription
FROM RFIDReceiver r
WHERE EXISTS (SELECT 1
FROM ra
WHERE r.ReceiverID = ra.ReceiverID
);
You can use CTE instead of the temp table:
WITH
CTE
AS
(
SELECT
a.ReceiverID,
a.AntennaID,
a.AntennaName
FROM
RFIDReceiverAntenna a
full join Station b
ON (a.ReceiverID = b.ReceiverID)
and (a.AntennaID = b.AntennaID)
where
(a.ReceiverID is NULL or b.ReceiverID is NULL)
and (a.AntennaID IS NULL or b.antennaID is NULL)
)
select distinct
r.ReceiverID, r.ReceiverName, r.receiverdescription
from
RFIDReceiver r
inner join CTE t on r.ReceiverID = t.ReceiverID
;
This query will return the same results as your original query with the temp table, but its performance may be quite different; not necessarily slower, it can be faster. Just something that you should be aware about.
I am trying to insert values into an integer array, used as path to show all ancestors of a particular node.
These values (parent_link integer) are from a table with ID and parent_link. I am trying to traverse the tree-like structure to assemble all parent_link in a path to insert into an integer array belonging to that particular ID. I am trying to do this for every single record in my database. So far I have:
INSERT INTO master_ifis_network (path)
SELECT t2.parent_link
FROM master_ifis_network as t2
WHERE t2.parent_link = (SELECT t1.parent_link
FROM master_ifis_network as t1)
AND t2.link_id = (parent_link)
I get an error saying that I cannot insert an integer where an integer[] is expected.
I have also tried this, which outputs a list of the parent nodes:
SELECT parentX.parent_link FROM [table name] as nodeX, [table name] as parentx
WHERE nodeX.left BETWEEN parentX.left AND parentX.right)
AND nodeX.link_id = [some id]
ORDER BY parentX.left DESC
Any hints or ideas?
Use a recursive CTE, i.e.: WITH RECURSIVE.
And you need an UPDATE, not an INSERT:
WITH RECURSIVE cte AS (
SELECT link_id, ARRAY[parent_link] AS path, 1 AS level
FROM master_ifis_network
UNION ALL
SELECT c.link_id, m.parent_link || c.path, c.level + 1
FROM cte c
JOIN master_ifis_network m ON m.link_id = c.path[1]
)
UPDATE master_ifis_network m
SET path = sub.path
FROM (
SELECT DISTINCT ON (link_id) *
FROM cte
ORDER BY link_id, level DESC
) sub
WHERE m.link_id = sub.link_id;
Related answers:
Tree Structure and Recursion
Recursive query used for transitive closure
There are many others here. Search with above key words.
Here is what I ended up with:
UPDATE master_ifis_network SET path = array(SELECT parentX.parent_link
FROM master_ifis_network AS parentX
WHERE (nodeX.left BETWEEN parentX.left AND parentX.right) AND nodeX.link_id = [some id]
ORDER BY parentX.left DESC)
WHERE link_id = [same id];"
I have a query like the following
select *
from (
select *
from callTableFunction(#paramPrev)
.....< a whole load of other joins, wheres , etc >........
) prevValues
full join
(
select *
from callTableFunction(#paramCurr)
.....< a whole load of other joins, wheres , etc >........
) currValues on prevValues.Field1 = currValues.Field1
....<other joins with the same subselect as the above two with different parameters passed in
where ........
group by ....
The following subselect is common to all the subselects in the query bar the #param to the table function.
select *
from callTableFunction(#param)
.....< a whole load of other joins, wheres , etc >........
One option is for me to convert this into a function and call the function, but i dont like this as I may be changing the
subselect query quite often for.....or I am wondering if there is an alternative using CTE
like
with sometable(#param1) as
(
select *
from callTableFunction(#param)
.....< a whole load of other joins, wheres , etc >........
)
select
sometable(#paramPrev) prevValues
full join sometable(#currPrev) currValues on prevValues.Field1 = currValues.Field1
where ........
group by ....
Is there any syntax like this or technique I can use like this.
This is in SQL Server 2008 R2
Thanks.
What you're trying to do is not supported syntax - CTE's cannot be parameterised in this way.
See books online - http://msdn.microsoft.com/en-us/library/ms175972.aspx.
(values in brackets after a CTE name are an optional list of output column names)
If there are only two parameter values (paramPrev and currPrev), you might be able to make the code a little easier to read by splitting them into two CTEs - something like this:
with prevCTE as (
select *
from callTableFunction(#paramPrev)
.....< a whole load of other joins, wheres , etc
........ )
,curCTE as (
select *
from callTableFunction(#currPrev)
.....< a whole load of other joins, wheres , etc
........ ),
select
prevCTE prevValues
full join curCTE currValues on
prevValues.Field1 = currValues.Field1 where
........ group by
....
You should be able to wrap the subqueries up as parameterized inline table-valued functions, and then use them with an OUTER JOIN:
CREATE FUNCTION wrapped_subquery(#param int) -- assuming it's an int type, change if necessary...
RETURNS TABLE
RETURN
SELECT * FROM callTableFunction(#param)
.....< a whole load of other joins, wheres , etc ........
GO
SELECT *
FROM
wrapped_subquery(#paramPrev) prevValues
FULL OUTER JOIN wrapped_subquery(#currPrev) currValues ON prevValues.Field1 = currValues.Field1
WHERE ........
GROUP BY ....
After failing to assign scalar variables before with, i finally got a working solution using a stored procedure and a temp table:
create proc hours_absent(#wid nvarchar(30), #start date, #end date)
as
with T1 as(
select c from t
),
T2 as(
select c from T1
)
select c from T2
order by 1, 2
OPTION(MAXRECURSION 365)
Calling the stored procedure:
if object_id('tempdb..#t') is not null drop table #t
create table #t([month] date, hours float)
insert into #t exec hours_absent '9001', '2014-01-01', '2015-01-01'
select * from #t
There may be some differences between my example and what you want depending on how your subsequent ON statements are formulated. Since you didn't specify, I assumed that all the subsequent joins were against the first table.
In my example I used literals rather than #prev,#current but you can easily substitute variables in place of literals to achieve what you want.
-- Standin function for your table function to create working example.
CREATE FUNCTION TestMe(
#parm int)
RETURNS TABLE
AS
RETURN
(SELECT #parm AS N, 'a' AS V UNION ALL
SELECT #parm + 1, 'b' UNION ALL
SELECT #parm + 2, 'c' UNION ALL
SELECT #parm + 2, 'd' UNION ALL
SELECT #parm + 3, 'e');
go
-- This calls TestMe first with 2 then 4 then 6... (what you don't want)
-- Compare these results with those below
SELECT t1.N AS AN, t1.V as AV,
t2.N AS BN, t2.V as BV,
t3.N AS CN, t3.V as CV
FROM TestMe(2)AS t1
FULL JOIN TestMe(4)AS t2 ON t1.N = t2.N
FULL JOIN TestMe(6)AS t3 ON t1.N = t3.N;
-- Put your #vars in place of 2,4,6 adding select statements as needed
WITH params
AS (SELECT 2 AS p UNION ALL
SELECT 4 AS p UNION ALL
SELECT 6 AS p)
-- This CTE encapsulates the call to TestMe (and any other joins)
,AllData
AS (SELECT *
FROM params AS p
OUTER APPLY TestMe(p.p)) -- See! only coded once
-- Add any other necessary joins here
-- Select needs to deal with all the columns with identical names
SELECT d1.N AS AN, d1.V as AV,
d2.N AS BN, d2.V as BV,
d3.N AS CN, d3.V as CV
-- d1 gets limited to values where p = 2 in the where clause below
FROM AllData AS d1
-- Outer joins require the ANDs to restrict row multiplication
FULL JOIN AllData AS d2 ON d1.N = d2.N
AND d1.p = 2 AND d2.p = 4
FULL JOIN AllData AS d3 ON d1.N = d3.N
AND d1.p = 2 AND d2.p = 4 AND d3.p = 6
-- Since AllData actually contains all the rows we must limit the results
WHERE(d1.p = 2 OR d1.p IS NULL)
AND (d2.p = 4 OR d2.p IS NULL)
AND (d3.p = 6 OR d3.p IS NULL);
What you want to do is akin to a pivot and so the complexity of the needed query is similar to creating a pivot result without using the pivot statement.
Were you to use Pivot, duplicate rows (such as I included in this example) would be aggreagted. This is also a solution for doing a pivot where aggregation is unwanted.
INSERT INTO files (fileUID, filename)
WITH fileUIDS(fileUID) AS
( VALUES(1) UNION ALL
SELECT fileUID+1 FROM fileUIDS WHERE fileUID < 1000 )
SELECT fileUID,
TRANSLATE ( CHAR(BIGINT(RAND() * 10000000000 )), 'abcdefgHij', '1234567890' )
FROM fileUIDS;
The WITH syntax is the same as using either a local temp table or inline view. To my knowledge, it's only supported in SQL Server (2005+, called Common Table Expressions) and Oracle (9i+, called Subquery Factoring). The intended use is for creating a basic view that is used (ie: joined to) multiple times in a single query.
Here's a typical example:
WITH example AS (
SELECT q.question_id,
t.tag_name
FROM QUESTIONS q
JOIN QUESTION_TAG_XREF qtf ON qtf.question_id = t.question_id
JOIN TAGS t ON t.tag_id = qtf.tag_id)
SELECT t.title,
e1.tag_name
FROM QUESTIONS t
JOIN example e1 ON e1.question_id = t.question_id
...which will return identical results if you use:
SELECT t.title,
e1.tag_name
FROM QUESTIONS t
JOIN (SELECT q.question_id,
t.tag_name
FROM QUESTIONS q
JOIN QUESTION_TAG_XREF qtf ON qtf.question_id = t.question_id
JOIN TAGS t ON t.tag_id = qtf.tag_id) e1 ON e1.question_id = t.question_id
The example you provided:
WITH fileUIDS(fileUID) AS (
VALUES(1)
UNION ALL
SELECT t.fileUID+1
FROM fileUIDS t
WHERE t.fileUID < 1000 )
INSERT INTO files
(fileUID, filename)
SELECT f.fileUID,
TRANSLATE ( CHAR(BIGINT(RAND() * 10000000000 )), 'abcdefgHij', '1234567890' )
FROM fileUIDS f;
...is a recursive one. It's starting at 1, generating 999 fileuids in total (it would be 1,000 if it had started at 0).
WITH x AS (...)
This will take the output of the ... and treat it as a table named x, temporarily.
WITH x AS (...)
SELECT * FROM x
This statement will essentially give you the exact same thing as the ... outputs but it will instead be referenced as the table x
The WITH word is used to create a Common Table Expression (CTE). In this case, it's creating an inline table that the "select fileUID, ..." part is pulling data from.
It is creating CTE (Common Table Expression). This is a basically a table that you don't have to create, drop, or declare in anyway. It will be automatically deleted after the batch has ran.
Check out https://web.archive.org/web/20210927200924/http://www.4guysfromrolla.com/webtech/071906-1.shtml for more info.