Temporary table in FROM clause instead of WITH clause - sql

I have this query (which runs perfect):
WITH TEMPTABLE AS(
SELECT count(CONTRACT_ID) AS no_contract, T.BRANCH_ID as branch
FROM CONTRACT, "EMPLOYMENT" T, TABLE(T."EMPLOYEE") TT
WHERE CONTRACT.EMPLOYEE_ID = TT.EMPLOYEE_ID
AND CONTRACT.CONTRACT_VT_START BETWEEN '01/01/2018' AND '30/06/2018'
GROUP BY T.BRANCH_ID
)
SELECT branch
FROM TEMPTABLE
WHERE no_contract IN (SELECT MAX(no_contract)
FROM TEMPTABLE);
And I was wondering if it can be done with another way instead of WITH clause. Something like this:
SELECT count_per_branch.BRANCH
FROM (SELECT count(CONTRACT_ID) AS no_contract, BRANCH_ID AS BRANCH
FROM CONTRACT, "EMPLOYMENT" T, TABLE(T."EMPLOYEE") TT
WHERE CONTRACT.EMPLOYEE_ID = TT.EMPLOYEE_ID
AND CONTRACT.CONTRACT_VT_START BETWEEN '01/01/2018' AND '30/06/2018'
GROUP BY T.BRANCH_ID) count_per_branch
WHERE count_per_branch.no_contract =
(SELECT max(count_per_branch.no_contract)
FROM count_per_branch);
Which gives an ORA-00942: "table or view does not exist"
Error at Line: 9

You can use a subquery in the FROM clause:
FROM (SELECT count(CONTRACT_ID) ... )
And you can give it an alias:
FROM (SELECT count(CONTRACT_ID) ... ) count_per_branch
And you can use that alias to qualify column references:
WHERE count_per_branch.no_contract =
But you cannot use that alias as a row source in another subquery, which is what you are trying to do here:
(SELECT max(count_per_branch.no_contract)
FROM count_per_branch)
To "reuse" a subquery in this manner, you have to use the Common Table Expression syntax -- i.e., the WITH clause.

Related

Pervasive SQL order by with if

In Pervasive SQL 11 I could use a IF statement in the ORDER BY:
SELECT *
FROM (
SELECT
D1001 as 'part_number',
'' as 'required_date',
'' as 'confirmed_date'
FROM PULAGER
WHERE
D1001 LIKE '1121%'
UNION
SELECT
D5410 as 'part_number',
D5511 as 'required_date',
D5513 as 'confirmed_date'
FROM PUIKOKRO
WHERE
D5410 LIKE '1121%'
) as t1
ORDER BY part_number, IF (confirmed_date = '', required_date, confirmed_date)
But after an upgrade version 15.10.031, I get the error "Reference to column name not allowed in ORDER BY with UNION". No error if I remove the IF statement. Any suggestions?
First order by part_number and then order by required_date or confirmed_date depending on the state of confirmed_date.
I solved it by moving the IF statement to the SELECT to create a new column 'sort_date' and wrapping it all with another SELECT. Doesn't feel like the most beautiful solution, but it works.
SELECT * FROM (
SELECT t1.*, IF (confirmed_date = '', required_date, confirmed_date) as 'sort_date' FROM t1
) ORDER BY part_number, sort_date

Oracle SQL use subquery value in another subquery

Before I go any further please mind that I am not well experienced with SQL.
I have one query that is getting a single value (netto value) such as:
WITH cte_value_net AS (
SELECT
nvl(min(value_net),0) as value_net
FROM (
SELECT
i.serial as serial,
nvl(lag(i.value_net) OVER (PARTITION BY i.serial ORDER BY i.month), i.value_net) as value_net
FROM
inventory i
WHERE
i.ctypde IN (
SELECT
ctypde
FROM
appar ap
WHERE
ap.serial = in_serial -- this is the variable I want to set
)
AND
i.month IN (to_char(add_months(sysdate, -1), 'YYYYMM'), to_char(add_months(sysdate, -2), 'YYYYMM'))
AND
i.serial = in_serial -- this is the variable I want to set
) vn
GROUP BY vn.serial
)
In here I have to feed in the variable in_serial that I thought I could get from another subquery such as:
SELECT
(SELECT * FROM cte_value_net) AS value_net
FROM (
SELECT
lap.serial AS in_serial
FROM
applap lap
)
but I can not wrap my head around it why this in_serial is not visible to my custom CTE. Could someone explain me how can I propagate the value from subquery like this?
The error I am obviously getting is:
SQL Error [904] [42000]: ORA-00904: "IN_SERIAL"
Unfortunately I do not have any sample data. What I want to achieve is that I could feed in the returned in_serial from main subquery to my CTE.
Before I can get value_net I need my main query to return the in_serial, otherwise I do not have access to that value.
The trick I use is to produce an extra CTE that I usually call params that includes a single row with all computed parameters. Then, it's a matter of performing a CROSS JOIN with this CTE in any other CTE, subquery or main query, as needed.
For example:
with
params as ( -- 1. Create a CTE that returns a single row
select serial as in_serial from applap
),
cte_value_net AS (
select ...
from inventory i
cross join params -- 2. cross join against the CTE anywhere you need it
where ...
and i.serial = params.in_serial -- 3. Use the parameter
)
select ...
First, your second query is not syntactically correct, as there's a ',' before the FROM. You can write your query like this:
WITH cte_value_net AS (
SELECT
serial, nvl(min(value_net),0) as value_net
FROM (
SELECT
i.serial as serial,
nvl(lag(i.value_net) OVER (PARTITION BY i.serial ORDER BY i.month), i.value_net) as value_net
FROM
inventory i
WHERE
i.ctypde IN (
SELECT
ctypde
FROM
appar ap
WHERE
ap.serial = i.serial
)
AND
i.month IN (to_char(add_months(sysdate, -1), 'YYYYMM'), to_char(add_months(sysdate, -2), 'YYYYMM'))
) vn
GROUP BY vn.serial
)
select ...
from cte_value_net s join applap lap on (lap.serial=s.serial)
(adjust query to your schema ....)

Apache Phoenix SQL Join Limitation when using sub-queries

I have this query in Apache Phoenix SQL:
select WO.* from (
select "nr_id", "txt_commrcial_label"
from "e_application" APP
where "txt_commrcial_label" in ('a','b')
and "nr_id" not in (select "nr_ap_id"
from "e_workorder"
where "nr_id" in ('888'))
and "epochtimestampchanged" = (select max("epochtimestampchanged")
from "e_application"
where "nr_id" = APP."nr_id") ) as APP2,
--
(select Y.ID as WO_ID, Y."nr_id" as WO_nr_id, Y."nr_ap_id" as WO_nr_ap_id
from ( select "nr_id", max("epochtimestampchanged") as max_epochtimestampchanged
from "e_workorder"
where CAST(TO_NUMBER("epochtimestampchanged") AS TIMESTAMP) < TO_TIMESTAMP('2020-10-21 19:22:20.0')
group by "nr_id" ) as X, "e_workorder" as Y
where Y."nr_id" = X."nr_id"
and Y."epochtimestampchanged" < X.max_epochtimestampchanged ) as WO
--
where APP2."nr_id" = WO.WO_nr_ap_id;
I get java language illegal ... blurb for this not overly complex statement. But I cannot see the reason here or in the manuals.
The individual queries work (imagine the ( and , are not there), but no joy when these 2 sub-queries merged to a JOIN.
Do I need to persist the results to tables and then JOIN? Or is there way around this? I have the impression this is too complex in terms of sub-queries.
For others to note, this is a big and a different SQL Approach is needed as per below which is a work-around with note from Cloudera:
The best workaround is to explicitly define a join in the APP2 query.
See the APP_MAX_TIMESTAMP table joined with the APP table, defining
basically the same condition as in the original query (but using a
table join instead of an inner select):
The query that should work and should do the same as the original
query:
select
WO.*
from
(
select
"nr_id",
"txt_commrcial_label"
from
"e_application" APP
LEFT JOIN (
select
max("epochtimestampchanged") as max_app_timestamp,
"nr_id" as max_app_timestamp_nr_id
from
"e_application"
group by "nr_id"
) APP_MAX_TIMESTAMP
ON APP_MAX_TIMESTAMP.max_app_timestamp_nr_id = APP."nr_id"
where
"txt_commrcial_label" in
( list
)
and "nr_id" not in
(
select
"nr_ap_id"
from
"e_workorder"
where
"nr_id" in
(
'888'
)
)
and "epochtimestampchanged" = max_app_timestamp
)
as APP2,
(
select
Y.ID as WO_ID,
Y."nr_id" as WO_nr_id,
Y."nr_ap_id" as WO_nr_ap_id
from
(
select
"nr_id",
max("epochtimestampchanged") as max_epochtimestampchanged
from
"e_workorder"
where
CAST(TO_NUMBER("epochtimestampchanged") AS TIMESTAMP) < TO_TIMESTAMP('2022-10-10 19:22:20.0')
group by
"nr_id"
)
as X,
"e_workorder" as Y
where
Y."nr_id" = X."nr_id"
and Y."epochtimestampchanged" < X.max_epochtimestampchanged
)
as WO
where
APP2."nr_id" = WO.WO_nr_ap_id;

With clause subquery availablility for the entire SQL statement in Oracle

I am trying to write a SQL statement which reuses the subquery of the With clause multiple times in Oracle.
With mySubQ as (
...
)
Select Something
From SomeTable,
(
Select *
From mySubQ
where mySubQ.Something >= 0
) newSubQ
where mySubQ.Something = SomeTable.Something
This gives me error - ORA-32034 unsupported use of WITH clause
What am I missing?
You need to join with mySubQ, not just define it.
WITH mySubQ AS (...)
SELECT Something
FROM SomeTable
JOIN mySubQ ON mySubQ.Something = SomeTable.Something
WHERE mySubQ.Something >= 0
If you put the query of mySubQ in a subquery, you can't reference mySubQ in the WHERE clause of the main query. Each level of query can only access tables in its own FROM and JOIN clauses, not those of subqueries.
Here is the error: where mySubQ.Something = SomeTable.Something.
The bottom query selects from SomeTable and from the subquery with alias newSubQ,
so mySubQ.Something is not known in this context.
If something is a real column name, not only a "placeholder in the pseudocode", then there is also another error here: Select Something - the column is ambiguous, because both sometable and the subquery have this column.
Try this query:
With mySubQ as (
SELECT * FROM sometable
)
Select newSubQ.Something
From SomeTable,
(
Select *
From mySubQ
where mySubQ.Something >= 0
) newSubQ
where newSubQ.Something = SomeTable.Something
;
Demo --> http://www.sqlfiddle.com/#!4/88855/12
This demo contains also another example of using WITH clause:
WITH mySubQ AS (
SELECT *
FROM sometable
),
mySubQ_1 AS (
SELECT *
FROM mySubQ
WHERE somethingelse = 1
),
mySubQ_2 AS (
SELECT *
FROM mySubQ
WHERE something between 2 AND 5
)
SELECT *
FROM sometable s, mySubQ_1 m1,
(
SELECT * FROM mySubQ_2
WHERE something < 10
) m2
WHERE s.something = m1.something
AND m1.somethingelse = m2.somethingelse

Reuse subquery result in WHERE-Clause for INSERT

i am using Microsoft SQL Server 2008
i would like to save the result of a subquery to reuse it in a following subquery.
Is this possible?
What is best practice to do this? (I am very new to SQL)
My query looks like:
INSERT INTO [dbo].[TestTable]
(
[a]
,[b]
)
SELECT
(
SELECT TOP 1 MAT_WS_ID
FROM #TempTableX AS X_ALIAS
WHERE OUTERBASETABLE.LT_ALL_MATERIAL = X_ALIAS.MAT_RM_NAME
)
,(
SELECT TOP 1 MAT_WS_NAME
FROM #TempTableY AS Y_ALIAS
WHERE Y_ALIAS.MAT_WS_ID = MAT_WS_ID
--(
--SELECT TOP 1 MAT_WS_ID
--FROM #TempTableX AS X_ALIAS
--WHERE OUTERBASETABLE.LT_ALL_MATERIAL = X_ALIAS.MAT_RM_NAME
--)
)
FROM [dbo].[LASERTECHNO] AS OUTERBASETABLE
My question is:
Is this correct what i did.
I replaced the second SELECT Statement in the WHERE-Clause for [b] (which is commented out and exactly the same as for [a]), with the result of the first SELECT Statement of [a] (=MAT_WS_ID).
It seems to give the right results.
But i dont understand why!
I mean MAT_WS_ID is part of both temporary tables X_ALIAS and Y_ALIAS.
So in the SELECT statement for [b], in the scope of the [b]-select-query, MAT_WS_ID could only be known from the Y_ALIAS table. (Or am i wrong, i am more a C++, maybe the scope things in SQL and C++ are totally different)
I just wannt to know what is the best way in SQL Server to reuse an scalar select result.
Or should i just dont care and copy the select for every column and the sql server optimizes it by its own?
One approach would be outer apply:
SELECT mat.MAT_WS_ID
, (
SELECT TOP 1 MAT_WS_NAME
FROM #TempTableY AS Y_ALIAS
WHERE Y_ALIAS.MAT_WS_ID = mat.MAT_WS_ID
)
FROM [dbo].[LASERTECHNO] AS OUTERBASETABLE
OUTER APPLY
(
SELECT TOP 1 MAT_WS_ID
FROM #TempTableX AS X_ALIAS
WHERE OUTERBASETABLE.LT_ALL_MATERIAL = X_ALIAS.MAT_RM_NAME
) as mat
You could rank rows in #TempTableX and #TempTableY partitioning them by MAT_RM_NAME in the former and by MAT_WS_ID in the latter, then use normal joins with filtering by rownum = 1 in both tables (rownum being the column containing the ranking numbers in each of the two tables):
WITH x_ranked AS (
SELECT
*,
rownum = ROW_NUMBER() OVER (PARTITION BY MAT_RM_NAME ORDER BY (SELECT 1))
FROM #TempTableX
),
y_ranked AS (
SELECT
*,
rownum = ROW_NUMBER() OVER (PARTITION BY MAT_WS_ID ORDER BY (SELECT 1))
FROM #TempTableY
)
INSERT INTO dbo.TestTable (a, b)
SELECT
x.MAT_WS_ID,
y.MAT_WS_NAME
FROM dbo.LASERTECHNO t
LEFT JOIN x_ranked x ON t.LT_ALL_MATERIAL = x.MAT_RM_NAME AND x.rownum = 1
LEFT JOIN y_ranked y ON x.MAT_WS_ID = y.MAT_WS_ID AND y.rownum = 1
;
The ORDER BY (SELECT 1) bit is a trick to specify an indeterminate ordering, which, accordingly, would result in indeterminate rownum = 1 rows picked by the query. That is to more or less duplicate your TOP 1 without an explicit order, but I would recommend you to specify a more sensible ORDER BY clause to make the results more predictable.