Forgive me, I don't know how to ask this question and google for an answer. May have already been answered elsewhere on Stack, let me know if it is.
I want to use postgresql to join one table, Table A, with Table B such that the values in one set of columns in Table A are joined and multiplied (one-to-many join) by the corresponding values in a set of columns in Table B, based on whether the values in the set of columns in Table B are within the range of the values in the set of columns in Table A.
Basically:
Where Start_A >= Start_B AND End_A <= End_B
Like so:
i think this can help you. But in your quest and result where you question "Basically: Where Start_A >= Start_B AND End_A <= End_B", I think this your mistake because in result i saw Start_A <= Start_B AND End_A >= End_B. And id write the query for you:
SELECT *
FROM a LEFT JOIN b ON startA <= startB
WHERE endA >= endB
Related
Goal: Create a query to pull the closest cycle count event (Table C) for a product ID based on the inventory adjustments results sourced from another table (Table A).
All records from Table A will be used, but is not guaranteed to have a match in Table C.
The ID column will be present in both tables, but is not unique in either, so that pair of IDs and Timestamps together are needed for each table.
Current simplified SQL
SELECT
A.WHENOCCURRED,
A.LPID,
A.ITEM,
A.ADJQTY,
C.WHENOCCURRED,
C.LPID,
C.LOCATION,
C.ITEM,
C.QUANTITY,
C.ENTQUANTITY
FROM
A
LEFT JOIN
C
ON A.LPID = C.LPID
WHERE
A.facility = 'FACID'
AND A.WHENOCCURRED > '23-DEC-22'
AND A.ADJREASONABBREV = 'CYCLE COUNTS'
ORDER BY A.WHENOCCURRED DESC
;
This is currently pulling the first hit on C.WHENOCCURRED on the LPID matches. Want to see if there is a simpler JOIN solution before going in a direction that creates 2 temp tables based on WHENOCCURRED.
I have a functioning INDEX(MATCH(MIN()) solution in Excel but that requires exporting a couple system reports first and is extremely slow with X,XXX row tables.
If you are using Oracle 12 or later, you can use a LATERAL join and FETCH FIRST ROW ONLY:
SELECT A.WHENOCCURRED,
A.LPID,
A.ITEM,
A.ADJQTY,
C.WHENOCCURRED,
C.LPID,
C.LOCATION,
C.ITEM,
C.QUANTITY,
C.ENTQUANTITY
FROM A
LEFT OUTER JOIN LATERAL (
SELECT *
FROM C
WHERE A.LPID = C.LPID
AND A.whenoccurred <= c.whenoccurred
ORDER BY c.whenoccurred
FETCH FIRST ROW ONLY
) C
ON (1 = 1) -- The join condition is inside the lateral join
WHERE A.facility = 'FACID'
AND A.WHENOCCURRED > DATE '2022-12-23'
AND A.ADJREASONABBREV = 'CYCLE COUNTS'
ORDER BY A.WHENOCCURRED DESC;
I'm trying to get the highlighted result only as it's the latest date. First time I've asked a question here so I apologize in advance if this isn't clear. Thanks
By using the following query
SELECT
MAX(A.Insp_Date) AS Last_Insp_Date
,A.Doc_ID
,A.Service_Call_ID
,A.Customer_ID
,A.Address_Code
,A.State
,A.Branch
,B.HydLoc
,B.FlwOutSz
,B.StaticPSI
,B.ResidualPSI
,B.PititPSI
,B.FlwGPM
FROM [dbo].[fofHydrntInspHdr] AS A
LEFT OUTER JOIN [dbo].[fofHYD2800FlwTstRT] AS B
ON A.Doc_ID = B.Doc_ID
WHERE A.Doc_ID > 0
AND A.Address_Code = 'GEN0021'
GROUP BY
A.Doc_ID
,A.Service_Call_ID
,A.Customer_ID
,A.Address_Code
,A.State
,A.Branch
,B.HydLoc
,B.FlwOutSz
,B.StaticPSI
,B.ResidualPSI
,B.PititPSI
,B.FlwGPM
I've also tried using max doc_id and it still doesn't work. Appreciate any help.
Another option that shouldn't require two scans of your table is to filter for the latest using a window function:
with r as
(
SELECT
A.Insp_Date AS Last_Insp_Date
,A.Doc_ID
,A.Service_Call_ID
,A.Customer_ID
,A.Address_Code
,A.State
,A.Branch
,B.HydLoc
,B.FlwOutSz
,B.StaticPSI
,B.ResidualPSI
,B.PititPSI
,B.FlwGPM
,DENSE_RANK() OVER (ORDER BY A.Insp_Date DESC) AS r
FROM [dbo].[fofHydrntInspHdr] AS A
LEFT OUTER JOIN [dbo].[fofHYD2800FlwTstRT] AS B
ON A.Doc_ID = B.Doc_ID
WHERE A.Doc_ID > 0
AND A.Address_Code = 'GEN0021'
)
SELECT
Insp_Date AS Last_Insp_Date
,Doc_ID
,Service_Call_ID
,Customer_ID
,Address_Code
,State
,Branch
,HydLoc
,FlwOutSz
,StaticPSI
,ResidualPSI
,PititPSI
,FlwGPM
FROM r
WHERE r = 1;
As an aside, I would advise against aliasing your tables with A, B, C etc as they don't relate to the table and make understanding the query later on more awkward. In this case, aliases like h and ft would convey that one table is the Headers and the other the Flow Tests, whilst also reducing character count.
It also looks like you have some bad duplication going on in your results there, which suggests that either your query is not joining and filtering appropriately or your data is messy.
I have two columns in the same table that I want to join in Postgresql but for some reason I’m getting this error. Don’t know how to figure it out. Please help.
[42P01] ERROR: relation "a" does not exist
Position: 10
X table contains two pools(ABC,XYZ), ids, numbers and description. If an ID exists in one pool but not in the other, it should update description column to “ADD”. Pools need to be joined on number.
UPDATE A
SET A.Description = 'ADD'
FROM X AS A
LEFT JOIN X AS B ON B.number = A.number
AND B.id = 'ABC'
WHERE A.id = 'XYZ'
AND B.number IS NULL
AND A.Description IS NULL;
With standard SQL you can't do a join as part of an update, but what you can do is include a subquery to select the id's to update. The subquery can contain a join. I'm not entirely clear on what you're actually trying to accomplish, but you could do something like this:
UPDATE x SET description='ADD' WHERE number IN (
SELECT a.number FROM x AS a
LEFT OUTER JOIN x AS b ON a.number=b.number AND a.id='XYZ' AND b.id='ABC'
WHERE b.number IS NULL
);
This will join the table x with itself and will select (and update) any numbers's that don't have a matching number in the 'ABC' and 'XYZ' zone.
PostgreSQL does have a UPDATE FROM syntax that does let you update with complex subqueries. It's more flexible but it's non-standard. You can find an example of this type of query here.
Selecting the rows from a table by (partial) key with the maximum value in a particular column is a common task in SQL. This question has some excellent answers that cover a variety of approaches to it. Unfortunately I'm struggling to replicate this in my ABAP program.
None of the commonly used approaches seem to be supported:
Joining on a subquery is not supported in syntax: SELECT * FROM X as x INNER JOIN ( SELECT ... ) AS y
Using IN for a composite key is not supported in syntax as far as I know: SELECT * FROM X WHERE (key1, key2) IN ( SELECT key1 key2 FROM ... )
Left join to itself with smaller-than comparison is not supported, outer joins only support EQ comparisons: SELECT * FROM X AS x LEFT JOIN X as xmax ON x-key1 = xmax-key1 AND x-key2 < xmax-key2 WHERE xmax-key IS INITIAL
After trying each of these solutions in turn only to discover that ABAP doesn't seem to support them and being unable to find any equivalents I'm starting to think that I'll have no choice but to dump the data of the subquery to an itab.
What is the best practice for this common programming requirement in ABAP development?
First of all, specific requirement, would give you a better answer. As it happens I bumped into this question when working on a program, that uses 3 distinct methods of pseudo-grouping, (while looking for alternatives) and ALL 3 can be used to answer your question, depending on what exactly you need to do. I'm sure there are more ways to do it.
For instance, you can pull maximum values within a group by simply selecting max( your_field ) and grouping by some fields, if that's all you need.
select bname, nation, max( date_from ) from adrp group by bname, nation. "selects highest "from" date for each bname
If you need to use that max value as a filter condition within a query, you can do it by performing pseudo-grouping using sub-query and max within sub-query like this (notice how I move out the BNAME check into sub query, which means I don't have to check both fields using in (subquery) addition):
select ... from adrp as b_adrp "Pulls the latest person info for a user (some conditions are missing, but this is a part of an actual query)
where b_adrp~date_from in (
select max( date_from ) "Highest date_from where both dates are valid
from adrp where persnumber = b_adrp~persnumber and nation = b_adrp~nation and date_from <= #sy-datum )
The query above allows you to select selects all user info from base query and (where the first one only allows to take aggregated and grouped data).
Finally, If you need to check based on composite key and compare it to multiple agregate function results, the implementation will heavily depend on specifics of your requirement (and since your question has none, I'll provide a generic one). Easiest option is to use exists / not exists instead of in (subquery), in exact same way and form the subquery to check for existance of specific key or condition rather than pull a list ( you can nest subqueries if you have to ):
select * from bkpf where exists ( select 1 from bkpf as b where belnr = bkpf~belnr and gjahr = bkpf~gjahr group by belnr, gjahr having max( budat ) = bkpf~budat ) "Took an available example, that I had in testing program.
All 3 queries will get you max value of a column within a group and in fact, all 3 can use joins to achieve identical results.
please find my answers below your questions.
Joining on a subquery is not supported in syntax: SELECT * FROM X as x INNER JOIN ( SELECT ... ) AS y
Putting the subquery in your where condition should do the work SELECT * FROM X AS x INNER JOIN Y AS y ON x~a = y~b WHERE ( SELECT * FROM y WHERE ... )
Using IN for a composite key is not supported in syntax as far as I know: SELECT * FROM X WHERE (key1, key2) IN ( SELECT key1 key2 FROM ... )
You have to split your WHERE clause: SELECT * FROM X WHERE key1 IN ( SELECT key1 FROM y ) AND key2 IN ( SELECT key2 FROM y )
Left join to itself with smaller-than comparison is not supported, outer joins only support EQ comparisons.
Yes, thats right at the moment.
Left join to itself with smaller-than comparison is not supported, outer joins only support EQ comparisons:
SELECT * FROM X AS x LEFT JOIN X as xmax ON x-key1 = xmax-key1 AND x-key2 < xmax-key2 WHERE xmax-key IS INITIAL
This is not true. This SELECT is perfectly valid:
SELECT b1~budat
INTO TABLE lt_bkpf
FROM bkpf AS b1
LEFT JOIN bkpf AS b2
ON b2~belnr < b1~belnr
WHERE b1~bukrs <> ''.
And was valid at least since 7.40 SP08, since July 2013, so at the time you asked this question it was valid as well.
If I have a table MyTable with columns a,b and c, which are ints. Given that I want to update all 'a's based on the values of b and c.
Update MyTable set a = 2 where b = 1 and c = 1
It's far too late, and I cannot for the life of me see why this statement doesn't work, am I missing something silly?
Edit, woops, forgot the error.
"Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression."
Edit2: That was the exact query I was using (different column names). Turns out there was a trigger on the table which was broken. I feel a little silly now, but thanks for the help anyway :)
There's nothing wrong with the statement you posted. The error is elsewhere.
Could you have posted the wrong query? Or perhaps you over-simplified it? A subquery looks something like this:
UPDATE MyTable
SET a = 2
WHERE b = 1 AND c = (SELECT c FROM MyTable2 WHERE id = 5)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ <--- subquery
An invalid query that could give the error message you get could look like this:
UPDATE MyTable
SET a = 2
WHERE b = 1 AND c = (SELECT c, d FROM MyTable2 WHERE id = 5)
The second query is invalid because it returns two values but the = operator only allows comparison to a single value.
The solution is to ensure that all subqueries used in equality comparisons only return a single row consisting of a single column.