I am trying to join two tables to the following query:
SELECT "NUMBER",
"U_ANALYZED_DATE",
"DV_SALES_ACCOUNT",
"U_USD_TOTAL_POTENTIAL_NNACV"
FROM
(select *, row_number() over ( partition by "DV_SALES_ACCOUNT" order by "U_ANALYZED_DATE" desc ) rownum
from "SURF_RT"."SALES_REQUEST")
WHERE rownum = 1
AND "DV_SALES_CATEGORY" = 'Compliance'
AND "DV_STATE" NOT IN ('Closed Canceled')
AND (YEAR("U_ANALYZED_DATE") = '2019' AND MONTH("U_ANALYZED_DATE") IN ('10','11','12')
OR YEAR("U_ANALYZED_DATE") = '2020' AND MONTH("U_ANALYZED_DATE") IN ('1','2','3'))
AND "U_USD_TOTAL_POTENTIAL_NNACV" > 0
ORDER BY "U_ANALYZED_DATE" desc
The tables should be joined as follows:
JOIN "SURF_RT"."SALES_ACCOUNT" on "SURF_RT"."SALES_ACCOUNT"."NAME" = "SURF_RT"."SALES_REQUEST"."DV_SALES_ACCOUNT"
JOIN "SURF_RT"."SALES_CONTRACT" on "SURF_RT"."SALES_CONTRACT"."DV_ACCOUNT" = "SURF_RT"."SALES_REQUEST"."DV_SALES_ACCOUNT"
I am getting an error no matter what I try and it has to be because of the partition. Does anyone know the solution here?
I suspect that you just need to alias the derived table so you can then refer to join it. In many databases this is mandatory anyway, but apparently not in Hana (otherwise your original query would not run).
But to join on a derived table (the resultset that is generated by the subquery), alias do help:
SELECT
...
FROM
(
select
*,
row_number() over ( partition by "DV_SALES_ACCOUNT" order by "U_ANALYZED_DATE" desc ) rownum
from "SURF_RT"."SALES_REQUEST"
) sr -- table alias
JOIN "SURF_RT"."SALES_ACCOUNT"
ON "SURF_RT"."SALES_ACCOUNT"."NAME" = "SURF_RT"."SALES_REQUEST"."DV_SALES_ACCOUNT"
JOIN "SURF_RT"."SALES_CONTRACT"
ON "SURF_RT"."SALES_CONTRACT"."DV_ACCOUNT" = sr."DV_SALES_ACCOUNT" --reference to the derived table
WHERE
...
Side notes:
you should use table aliases for other tables involved in the query too, in order to make the code more readable
you should also prefix each column in the query with the identifier of the table it belongs to, so the query is unambiguous (and easier to maintain)
The problem with this query is not "that the where rownum = 1 needs to be at the end" but that the OP got confused by the bracketing of SQL expression.
More specifically, trying to reference the sub-query data by specifying join conditions against the base table that is used in the sub-query:
JOIN "SURF_RT"."SALES_ACCOUNT"
on "SURF_RT"."SALES_ACCOUNT"."NAME" = "SURF_RT"."SALES_REQUEST"."DV_SALES_ACCOUNT"
JOIN "SURF_RT"."SALES_CONTRACT"
on "SURF_RT"."SALES_CONTRACT"."DV_ACCOUNT" = "SURF_RT"."SALES_REQUEST"."DV_SALES_ACCOUNT"
Since the sub-query (derived table) is used in the query and should be used for the join, it needs to be referred in the join condition, instead.
So, yes, it needs a table alias here and the join conditions need to refer to it.
SELECT
...
FROM
(select *
, row_number() over
(partition by "DV_SALES_ACCOUNT"
order by "U_ANALYZED_DATE" desc) rownum
from
"SURF_RT"."SALES_REQUEST") sr
INNER JOIN "SURF_RT"."SALES_ACCOUNT" sa
on sa."NAME" = sr."DV_SALES_ACCOUNT"
INNER JOIN "SURF_RT"."SALES_CONTRACT" sc
on sc."DV_ACCOUNT" = sr."DV_SALES_ACCOUNT"
WHERE
sr.rownum = 1
AND "DV_SALES_CATEGORY" = 'Compliance'
AND "DV_STATE" NOT IN ('Closed Canceled')
AND (YEAR("U_ANALYZED_DATE") = '2019'
AND MONTH("U_ANALYZED_DATE") IN ('10','11','12')
OR YEAR("U_ANALYZED_DATE") = '2020'
AND MONTH("U_ANALYZED_DATE") IN ('1','2','3'))
AND "U_USD_TOTAL_POTENTIAL_NNACV" > 0
ORDER BY
"U_ANALYZED_DATE" desc;
With just this little bit of standard SQL syntax and formatting of code the query got a lot easier to understand.
Now it's even obvious that the IN conditions for MONTH and YEAR should in fact be integers, not strings as these functions return integers.
SELECT
...
FROM
(SELECT *
, row_number() over
(partition by "DV_SALES_ACCOUNT"
order by "U_ANALYZED_DATE" desc) rownum
FROM
"SURF_RT"."SALES_REQUEST") sr
INNER JOIN "SURF_RT"."SALES_ACCOUNT" sa
on sa."NAME" = sr."DV_SALES_ACCOUNT"
INNER JOIN "SURF_RT"."SALES_CONTRACT" sc
on sc."DV_ACCOUNT" = sr."DV_SALES_ACCOUNT"
WHERE
sr.rownum = 1
AND "DV_SALES_CATEGORY" = 'Compliance'
AND "DV_STATE" NOT IN ('Closed Canceled')
AND ( YEAR("U_ANALYZED_DATE") = 2019
AND MONTH("U_ANALYZED_DATE") IN (10, 11, 12)
OR YEAR("U_ANALYZED_DATE") = '2020'
AND MONTH("U_ANALYZED_DATE") IN (1 , 2 , 3 )
)
AND "U_USD_TOTAL_POTENTIAL_NNACV" > 0
ORDER BY
"U_ANALYZED_DATE" DESC
Related
I need to join to the same table repeatedly but this looks ugly. Any suggestions appreciated. Below is simplified SQL, I have 8 tables in the subquery and it produces many duplicate records of the same date, so I need to find only the newest record for each client. (I don't think DB and/or version should matter, but I am using DB2 11.1 LUW)
select c.client_num, a.eff_date, t.trx_date
from client c
join address a on(a.id = c.addr_id)
join transaction t on(t.addr_id = a.id)
{many other joins}
where {many conditions};
select SQ.*
from [ABOVE_SUBQUERY] SQ
join
(select client_num, max(eff_date) AS newest_date from [ABOVE_SUBQUERY] group by client_num) AA
ON(SQ.client_num = AA.client_num and SQ.eff_date = AA.newest_date)
join
(select client_num, max(trx_date) AS newest_date from [ABOVE_SUBQUERY] group by client_num) TT
ON(SQ.client_num = TT.client_num and SQ.trx_date = TT.newest_date)
I need to fine only the newest record for each client.
Can't you just use row_number()?
select t.*
from (select t.*,
row_number() over (partition by client_num order by eff_date desc, eff_time desc) as seqnum
from <whatever> t
) t
where seqnum = 1;
So I've done some looking around and wasn't unable to find quite what I was looking for. I have two tables.
1.) Table where general user information is stored
2.) Where a status is generated and stored.
The problem is, is that there are multiple rows for the same users and querying these results in multiple returns. I can't just merge them because they aren't all the same status. I need just the newest status from that table.
Example of the table:
SELECT DISTINCT
TOP(50) cam.UserID AS PatientID,
mppi.DisplayName AS Surgeon,
ISNULL(sci.IOPStatus, 'N/A') AS Status,
tkstat.TrackerStatusID AS Stat_2
FROM
Main AS cam
INNER JOIN
Providers AS rap
ON cam.VisitID = rap.VisitID
INNER JOIN
ProviderInfo AS mppi
ON rap.UnvUserID = mppi.UnvUserID
LEFT OUTER JOIN
Inop AS sci
ON cam.CwsID = sci.CwsID
LEFT OUTER JOIN
TrackerStatus AS tkstat
ON cam.CwsID = tkstat.CwsID
WHERE
(
cam.Location_ID IN
(
'SURG'
)
)
AND
(
rap.IsAttending = 'Y'
)
AND
(
cam.DateTime BETWEEN CONCAT(CAST(GETDATE() AS DATE), ' 00:00:00') AND CONCAT(CAST(GETDATE() AS DATE), ' 23:59:59')
)
AND
(
cam.Status_StatusID != 'Cancelled'
)
ORDER BY
cam.UserID ASC
So I need to grab only the newest Stat_2 from each ID so they aren't returning multiple rows. Each Stat_2 also has an update time meaning I can sort by the time/date that column is : StatusDateTime
One way to handle this is to create a calculated row_number for the table where you need the newest record.
Easiest way to do that is to change your TKSTAT join to a derived table with the row_number calculation and then add a constraint to your join where the RN =1
SELECT DISTINCT TOP (50)
cam.UserID AS PatientID, mppi.DisplayName AS Surgeon, ISNULL(sci.IOPStatus, 'N/A') AS Status, tkstat.TrackerStatusID AS Stat_2
FROM Main AS cam
INNER JOIN Providers AS rap ON cam.VisitID = rap.VisitID
INNER JOIN ProviderInfo AS mppi ON rap.UnvUserID = mppi.UnvUserID
LEFT OUTER JOIN Inop AS sci ON cam.CwsID = sci.CwsID
LEFT OUTER JOIN (SELECT tk.CwsID, tk.TrackerStatusId, ROW_NUMBER() OVER (PARTITION BY tk.cwsId ORDER BY tk.CreationDate DESC) AS rn FROM TrackerStatus tk)AS tkstat ON cam.CwsID = tkstat.CwsID
AND tkstat.rn = 1
WHERE (cam.Location_ID IN ( 'SURG' )) AND (rap.IsAttending = 'Y')
AND (cam.DateTime BETWEEN CONCAT(CAST(GETDATE() AS DATE), ' 00:00:00') AND CONCAT(CAST(GETDATE() AS DATE), ' 23:59:59'))
AND (cam.Status_StatusID != 'Cancelled')
ORDER BY cam.UserID ASC;
Note you need a way to derive what the "newest" status is; I assume there is a created_date or something; you'll need to enter the correct colum name
ROW_NUMBER() OVER (PARTITION BY tk.cwsId ORDER BY tk.CreationDate DESC) AS rn
SQL Server doesn't offer a FIRST function, but you can reproduce the functionality with ROW_NUMBER() like this:
With Qry1 (
Select <other columns>,
ROW_NUMBER() OVER(
PARTITION BY <group by columns>
ORDER BY <time stamp column*> DESC
) As Seq
From <the rest of your select statement>
)
Select *
From Qry1
Where Seq = 1
* for the "newest" record.
I have Oracle SQL like these :
SELECT
z."date", z.id_outlet as idOutlet, z.name as outletName, z.matClass, z.targetBulanan, z.targetBulanan/totalVisit as targetAwal,
z.actual,rownumber = tartot + rownumber as targetTotal
FROM (SELECT
b.visit_date as "date", a.id_outlet, max(o.name) as name, max(a.target_sales) as targetBulanan, a.id_material_class as matClass,
max(x.totalVisit) as totalVisit, NVL(SUM(d.billing_value),0) as actual
FROM (
select * from target_bulanan
where deleted = 0 and enabled = 1 and id_salesman = :id_salesman AND id_material_class like :id_material_class AND id_outlet like :id_outlet AND month = TO_NUMBER(TO_CHAR(current_date,'mm')) and year = to_number(TO_CHAR(current_date,'YYYY'))
) a
INNER JOIN outlet o ON o.id_outlet = a.id_outlet
LEFT JOIN visit_plan b ON b.deleted = 0 and a.id_salesman = b.id_salesman AND a.month = TO_NUMBER(TO_CHAR(b.visit_date,'mm')) AND a.year = to_number(TO_CHAR(b.visit_date,'yyyy')) AND a.id_outlet = b.id_outlet
LEFT JOIN so_header c ON SUBSTR(c.id_to,'0',1) = 'TO' AND a.id_salesman = c.id_salesman AND a.id_outlet = c.id_outlet
LEFT JOIN assign_billing d ON c.no_so_sap = d.no_so_sap AND d.billing_date = b.visit_date AND a.id_material_class = (SELECT id_material_class FROM material WHERE id = d.id_material)
LEFt JOIN (SELECT id_salesman, to_char(visit_date,'mm') as month, to_char(visit_date,'yyyy') as year, id_outlet, COUNT(*) as totalVisit FROM visit_plan
WHERE deleted = 0
group by id_salesman, id_outlet,to_char(visit_date,'mm'), to_char(visit_date,'yyyy')) x on
x.id_salesman = a.id_salesman AND x.month = a.month AND x.year = a.year AND x.id_outlet = a.id_outlet
GROUP BY b.visit_date, a.id_outlet, a.id_material_class) z
CROSS JOIN (SELECT 0 as rownumber FROM DUAL ) r
CROSS JOIN (SELECT 0 as tartot FROM DUAL ) t
CROSS JOIN (SELECT '' as mat FROM DUAL ) m
CROSS JOIN (SELECT '' as outlet FROM DUAL ) o
ORDER by outletName, z.matClass, z."date"
I want value of rownumber is formula in my select query but the result is error with this message
ORA-00923: FROM keyword not found where expected
00923. 00000 - "FROM keyword not found where expected"
Anyone can help me ? thanks
Just for enumeration -
replace the line
rownumber = rownumber + 1 AS row_number
with this
rownum AS row_number
rownum is an Oracle inbuilt function that enumerates each record of the result set and with auto increments
As mentioned by Gordon Linoff in his answer, there are further problems in your query.
At the first look (without executing it), I could list the problematic lines -
AND month = TO_NUMBER(TO_CHAR(current_date,'mm'))
AND year = to_number(TO_CHAR(current_date,'YYYY'))
Instead of current_date use sysdate
LEFT JOIN so_header c ON SUBSTR(c.id_to,'0',1) = 'TO'
I guess, you meant to do this -
LEFT JOIN so_header c ON SUBSTR(c.id_to,0,2) = 'TO'
i.e. substring from index 0 upto 2 characters
Plus, no need of those cross joins
THIS ADDRESSES THE ORIGINAL QUESTION.
You may have multiple problems in your query. After all, the best way to debug and to write queries is to start simple and gradually add complexity.
But, you do have an obvious error. In your outermost select:
SELECT z."date", z.id_outlet as idOutlet, z.name as outletName,
z.matClass, z.targetBulanan, z.targetBulanan/totalVisit as targetAwal,
z.actual,
rownumber = rownumber + 1 as row_number
The = is not Oracle syntax -- it looks like a SQL Server extension for naming a column or a MySQL use of variables.
I suspect that you want to enumerate the rows. If so, one syntax is row_number():
SELECT z."date", z.id_outlet as idOutlet, z.name as outletName,
z.matClass, z.targetBulanan, z.targetBulanan/totalVisit as targetAwal,
z.actual,
row_number() over (order by outletName, z.matClass, z."date") as row_number
In Oracle, you could also do:
rownum as row_number
I had this query, which gives me the desired results on postgres
SELECT
t.*,
ROW_NUMBER() OVER (PARTITION BY t."Internal_reference", t."Movement_date" ORDER BY t."Movement_date") AS "cnt"
FROM (SELECT
"Internal_reference",
MAX("Movement_date") AS maxtime
FROM dw."LO-D4_Movements"
GROUP BY "Internal_reference") r
INNER JOIN dw."LO-D4_Movements" t
ON t."Movement_date" = r.maxtime
AND t."Internal_reference" = r."Internal_reference"
Issue is I have to translate the query above on Access where the analytical function does not exist ...
I used this answer to build the query below
SELECT
t."Internal_reference",
t.from_code,
t.to_code,
t."Movement_date",
t.shipment_number,
t."PO_number",
t."Quantity",
t."Movement_value",
t."Site",
t."Import_date",
COUNT(*) AS "cnt"
FROM (
SELECT "Internal_reference",
MAX("Movement_date") AS maxtime
FROM dw."LO-D4_Movements"
GROUP BY "Internal_reference") r
LEFT OUTER JOIN dw."LO-D4_Movements" t
ON t."Movement_date" = r.maxtime AND t."Internal_reference" = r."Internal_reference"
GROUP BY
t.from_code,
t.to_code,
t."Movement_date",
t.shipment_number,
t."PO_number",
t."Quantity",
t."Movement_value",
t."Site",
t."Import_date",
t."Internal_reference"
ORDER BY t.from_code
Issue is I only have 1 in the cnt column.
I tried to tweak it by removing the internal_reference (see below)
SELECT
t.from_code,
t.to_code,
t."Movement_date",
t.shipment_number,
t."PO_number",
t."Quantity",
t."Movement_value",
t."Site",
t."Import_date",
COUNT(*) AS "cnt"
FROM (
SELECT "Internal_reference",
MAX("Movement_date") AS maxtime
FROM dw."LO-D4_Movements"
GROUP BY "Internal_reference") r
LEFT OUTER JOIN dw."LO-D4_Movements" t
ON t."Movement_date" = r.maxtime AND t."Internal_reference" = r."Internal_reference"
GROUP BY
t.from_code,
t.to_code,
t."Movement_date",
t.shipment_number,
t."PO_number",
t."Quantity",
t."Movement_value",
t."Site",
t."Import_date"
ORDER BY t.from_code
However, the results are even worse. The cnt is growing but it gives me the wrong cnt
Any help are more than welcome as I'm slow losing my sanity.
Thanks
Edit: Please find the sqlfiddle
I think Gordon-Linoff's code is close to what you want, but there are some typos I couldn't correct without a rewrite, so here's my attempt
SELECT
t1.Internal_reference,
t1.Movement_date,
t1.PO_Number as Combination_Of_Columns_Which_Make_This_Unique,
t1.Other_columns,
Count(1) AS Cnt
FROM
([LO-D4_Movements] AS t1
INNER JOIN [LO-D4_Movements] AS t2 ON
t1.Internal_reference = t2.Internal_reference AND
t1.Movement_date = t2.Movement_date)
INNER JOIN (
SELECT
t3.Internal_reference,
MAX(t3.Movement_date) AS Maxtime
FROM
[LO-D4_Movements] AS t3
GROUP BY
t3.Internal_reference
) AS r ON
t1.Internal_reference = r.Internal_reference AND
t1.Movement_date = r.Maxtime
WHERE
t1.PO_Number>=t2.PO_Number
GROUP BY
t1.Internal_reference,
t1.Movement_date,t1.PO_Number,
t1.Other_columns
ORDER BY
t1.Internal_reference,
t1.Movement_date,
Count(1);
In addition to within the max(movement_date) subquery, the main table is brought in twice. One version is the one for showing in your results, the other is for counting records to generate the sequence numbers.
Gordon said you need a unique id column for each row. And that's true if by "column" you mean to include derived columns also. Also it only needs to be unique within any combination of "internal_reference" and "Movement_date".
I've assumed, perhaps wrongly, that PO_Number will suffice. If not, concatenate with that (and some delimeters) other fields which will make it unique. The where clause will need updating to compare t1 and t2 for the "Combination of Columns which make this unique".
If, there is no appropriate combination available, I'm not sure it can be done without VBA and/or temp tables as The-Gambill suggested.
This is a real pain in MS Access, as far as I know. One method is a correlated subquery, but you need a unique id column on each row:
SELECT t.*,
(SELECT COUNT(*)
FROM (SELECT "Internal_reference", MAX("Movement_date") AS maxtime
FROM dw."LO-D4_Movements"
GROUP BY "Internal_reference"
) as t2
WHERE t2."Internal_reference" AND t."Internal_reference" AND
t2."Movement_date" = t."Movement_date" AND
t2.?? <= t.??
) as cnt
FROM (SELECT "Internal_reference", MAX("Movement_date") AS maxtime
FROM dw."LO-D4_Movements"
GROUP BY "Internal_reference"
) r INNER JOIN
dw."LO-D4_Movements" t
ON t."Movement_date" = r.maxtime AND
t."Internal_reference" = r."Internal_reference";
The ?? is for the id or creation date or something to allow the counting of rows.
I have the following query:
SELECT sum((select count(*) as itemCount) * "SalesOrderItems"."price") as amount, 'rma' as
"creditType", "Clients"."company" as "client", "Clients".id as "ClientId", "Rmas".*
FROM "Rmas" JOIN "EsnsRmas" on("EsnsRmas"."RmaId" = "Rmas"."id")
JOIN "Esns" on ("Esns".id = "EsnsRmas"."EsnId")
JOIN "EsnsSalesOrderItems" on("EsnsSalesOrderItems"."EsnId" = "Esns"."id" )
JOIN "SalesOrderItems" on("SalesOrderItems"."id" = "EsnsSalesOrderItems"."SalesOrderItemId")
JOIN "Clients" on("Clients"."id" = "Rmas"."ClientId" )
WHERE "Rmas"."credited"=false AND "Rmas"."verifyStatus" IS NOT null
GROUP BY "Clients".id, "Rmas".id;
The problem is that the table "EsnsSalesOrderItems" can have the same EsnId in different entries. I want to restrict the query to only pull the last entry in "EsnsSalesOrderItems" that has the same "EsnId".
By "last" entry I mean the following:
The one that appears last in the table "EsnsSalesOrderItems". So for example if "EsnsSalesOrderItems" has two entries with "EsnId" = 6 and "createdAt" = '2012-06-19' and '2012-07-19' respectively it should only give me the entry from '2012-07-19'.
SELECT (count(*) * sum(s."price")) AS amount
, 'rma' AS "creditType"
, c."company" AS "client"
, c.id AS "ClientId"
, r.*
FROM "Rmas" r
JOIN "EsnsRmas" er ON er."RmaId" = r."id"
JOIN "Esns" e ON e.id = er."EsnId"
JOIN (
SELECT DISTINCT ON ("EsnId") *
FROM "EsnsSalesOrderItems"
ORDER BY "EsnId", "createdAt" DESC
) es ON es."EsnId" = e."id"
JOIN "SalesOrderItems" s ON s."id" = es."SalesOrderItemId"
JOIN "Clients" c ON c."id" = r."ClientId"
WHERE r."credited" = FALSE
AND r."verifyStatus" IS NOT NULL
GROUP BY c.id, r.id;
Your query in the question has an illegal aggregate over another aggregate:
sum((select count(*) as itemCount) * "SalesOrderItems"."price") as amount
Simplified and converted to legal syntax:
(count(*) * sum(s."price")) AS amount
But do you really want to multiply with the count per group?
I retrieve the the single row per group in "EsnsSalesOrderItems" with DISTINCT ON. Detailed explanation:
Select first row in each GROUP BY group?
I also added table aliases and formatting to make the query easier to parse for human eyes. If you could avoid camel case you could get rid of all the double quotes clouding the view.
Something like:
join (
select "EsnId",
row_number() over (partition by "EsnId" order by "createdAt" desc) as rn
from "EsnsSalesOrderItems"
) t ON t."EsnId" = "Esns"."id" and rn = 1
this will select the latest "EsnId" from "EsnsSalesOrderItems" based on the column creation_date. As you didn't post the structure of your tables, I had to "invent" a column name. You can use any column that allows you to define an order on the rows that suits you.
But remember the concept of the "last row" is only valid if you specifiy an order or the rows. A table as such is not ordered, nor is the result of a query unless you specify an order by
Necromancing because the answers are outdated.
Take advantage of the LATERAL keyword introduced in PG 9.3
left | right | inner JOIN LATERAL
I'll explain with an example:
Assuming you have a table "Contacts".
Now contacts have organisational units.
They can have one OU at a point in time, but N OUs at N points in time.
Now, if you have to query contacts and OU in a time period (not a reporting date, but a date range), you could N-fold increase the record count if you just did a left join.
So, to display the OU, you need to just join the first OU for each contact (where what shall be first is an arbitrary criterion - when taking the last value, for example, that is just another way of saying the first value when sorted by descending date order).
In SQL-server, you would use cross-apply (or rather OUTER APPLY since we need a left join), which will invoke a table-valued function on each row it has to join.
SELECT * FROM T_Contacts
--LEFT JOIN T_MAP_Contacts_Ref_OrganisationalUnit ON MAP_CTCOU_CT_UID = T_Contacts.CT_UID AND MAP_CTCOU_SoftDeleteStatus = 1
--WHERE T_MAP_Contacts_Ref_OrganisationalUnit.MAP_CTCOU_UID IS NULL -- 989
-- CROSS APPLY -- = INNER JOIN
OUTER APPLY -- = LEFT JOIN
(
SELECT TOP 1
--MAP_CTCOU_UID
MAP_CTCOU_CT_UID
,MAP_CTCOU_COU_UID
,MAP_CTCOU_DateFrom
,MAP_CTCOU_DateTo
FROM T_MAP_Contacts_Ref_OrganisationalUnit
WHERE MAP_CTCOU_SoftDeleteStatus = 1
AND MAP_CTCOU_CT_UID = T_Contacts.CT_UID
/*
AND
(
(#in_DateFrom <= T_MAP_Contacts_Ref_OrganisationalUnit.MAP_KTKOE_DateTo)
AND
(#in_DateTo >= T_MAP_Contacts_Ref_OrganisationalUnit.MAP_KTKOE_DateFrom)
)
*/
ORDER BY MAP_CTCOU_DateFrom
) AS FirstOE
In PostgreSQL, starting from version 9.3, you can do that, too - just use the LATERAL keyword to achieve the same:
SELECT * FROM T_Contacts
--LEFT JOIN T_MAP_Contacts_Ref_OrganisationalUnit ON MAP_CTCOU_CT_UID = T_Contacts.CT_UID AND MAP_CTCOU_SoftDeleteStatus = 1
--WHERE T_MAP_Contacts_Ref_OrganisationalUnit.MAP_CTCOU_UID IS NULL -- 989
LEFT JOIN LATERAL
(
SELECT
--MAP_CTCOU_UID
MAP_CTCOU_CT_UID
,MAP_CTCOU_COU_UID
,MAP_CTCOU_DateFrom
,MAP_CTCOU_DateTo
FROM T_MAP_Contacts_Ref_OrganisationalUnit
WHERE MAP_CTCOU_SoftDeleteStatus = 1
AND MAP_CTCOU_CT_UID = T_Contacts.CT_UID
/*
AND
(
(__in_DateFrom <= T_MAP_Contacts_Ref_OrganisationalUnit.MAP_KTKOE_DateTo)
AND
(__in_DateTo >= T_MAP_Contacts_Ref_OrganisationalUnit.MAP_KTKOE_DateFrom)
)
*/
ORDER BY MAP_CTCOU_DateFrom
LIMIT 1
) AS FirstOE
Try using a subquery in your ON clause. An abstract example:
SELECT
*
FROM table1
JOIN table2 ON table2.id = (
SELECT id FROM table2 WHERE table2.table1_id = table1.id LIMIT 1
)
WHERE
...