What I wanted was to use CROSS APPLY, but I guess that doesn't exist in mysql. The alternative I've read is LATERAL. Well, I'm using mariadb 10.3 and I guess that doesn't exist either. The ticket table contains an id that's referenced by the ticket_id column in the note table. A ticket can have many notes, I'm trying to list all tickets with their most recent note date (post_date). How could I write the query below for mariadb?
SELECT t.*, n.post_date
FROM ticket t,
LATERAL (
SELECT note.post_date FROM note WHERE t.id = note.ticket_id ORDER BY note.post_date DESC LIMIT 1
) n;
Example table structure:
Ticket
id
subject
1
stuff
2
more
note
id
post_date
ticket_id
1
1
2
1
3
2
4
1
5
2
I did find an open jira ticket from people asking for mariadb to support lateral.
From what I read, LATERAL will not be supported in MariaDB until version 11. But we can just as easily use ROW_NUMBER here, which is supported:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY ticket_id ORDER BY post_date DESC) rn
FROM note
)
SELECT t.*, n.post_date
FROM ticket t
INNER JOIN cte n
ON n.ticket_id = t.id
WHERE n.rn = 1;
If you wanted a close translation of your current lateral join, then use:
SELECT t.*,
(SELECT n.post_date
FROM note n
WHERE t.id = note.ticket_id
ORDER BY n.post_date DESC
LIMIT 1)
FROM ticket t;
Related
I have a SQL query in teradata that returns a results set of ~160m rows in (I guess) a reasonable time: dependent on how good a day the server is having it runs between 10-60 minutes.
I recently got access to space to save it as a table, however using my initial query and the "insert into " command I get error 2646-no more spool.
query structure is
insert into <test_DB.tablename>
with smaller_dataset as
(
select
*
from
(
select
items
,case items
from
<Database.table>
QUALIFY ROW_NUMBER() OVER (PARTITION BY A,B ORDER BY C desc , LAST_UPDATE_DTM DESC) = 1
where 1=1
and other things
) T --irrelevant alias for subquery
QUALIFY ROW_NUMBER() OVER (PARTITION BY A, B ORDER BY C desc) = 1)
, employee_table as
(
select
items
,max(J1.field1) J1_field1
,max(J2.field1) J2_field1
,max(J3.field1) J3_field1
,max(J4.field1) J4_field1
from smaller_dataset S
self joins J1,J2,J3,J4
group by
non-aggregate items
)
select
items
case items
from employee_table
;
How can I break up the return into smaller chunks to prevent this error?
I have a table like this
CREATE TABLE "modules" ( `ID` INTEGER PRIMARY KEY AUTOINCREMENT, `name` TEXT, `version` TEXT, `deployID` INTEGER )
I want to be able to get all the rows from this database where the version is different between different deploy ID's. So, say I have a deploy ID 2 and a deployID 3 - my table might have 2000 odd modules for each of these deploys. I want to only get the rows where the name is the same but the version is different. Is this possible? I thought this query would do it but it seems to be returning me everything - twice!
SELECT a.* FROM modules a
INNER JOIN modules b
ON a.name == b.name
WHERE a.version != b.version
AND a.deployID = 3
AND b.deployID = 2
If you only care about deployids 2 and 3:
select m.*
from modules m
where
m.deployid in (2, 3)
and
exists (
select 1 from modules
where
name = m.name
and
deployID <> m.deployID
and
version <> m.version
)
If you don't need this condition:
deployID <> m.deployID
you can remove it.
I would probably use an exists query here:
SELECT m1.*
FROM modules m1
WHERE EXISTS (SELECT 1 FROM modules m2
WHERE m1.name = m2.name AND
m1.deployID <> m2.deployID AND m1.version <> m2.version);
Or maybe you want a more specific version:
SELECT m1.*
FROM modules m1
WHERE EXISTS (SELECT 1 FROM modules m2
WHERE m1.name = m2.name AND
LEAST(m1.deployID, m2.deployID) = 2 AND
GREATEST(m1.deployID, m2.deployID) = 3);
I have a oracle query
select id from (
select ID, ROW_NUMBER() over (partition by LATEST_RECEIPT order by ID) rownumber
from Table
where LATEST_RECEIPT in
(
select LATEST_RECEIPT from Table
group by LATEST_RECEIPT
having COUNT(1) > 1
)
) t
where rownumber <> 1;
The data type of LATEST_RECEIPT was earlier varchar2(4000) and this query worked fine. Since the length of the column needs to be extended i modified it to CLOB, after which this fails. Could anyone help me fix this issue or provide a work around?
You can change your inner query to look for other rows with the same last_receipt value but a different ID (assuming ID is unique); if another row exists then that is equivalent to your count returning greater than one. But you can't simply test two CLOB values for equality, you need to use dbms_lob.compare:
select ID
from your_table t1
where exists (
select null from your_table t2
where dbms_lob.compare(t2.LATEST_RECEIPT, t1.LATEST_RECEIPT) = 0
and t2.ID != t1.ID
-- or if ID isn't unique: and t2.ROWID != t1.ROWID
);
Applying the row number filter is tricker, as you also can't use a CLOB in the analytic partition by clause. As André Schild suggested, you can use a hash; here passing the integer value 3, which is the equivalent of dbms_crypto.hash_sh1 (though in theory that could change in a future release!):
select id from (
select ID, ROW_NUMBER() over (partition by dbms_crypto.hash(LATEST_RECEIPT, 3)
order by ID) rownumber
from your_table t1
where exists (
select null from your_table t2
where dbms_lob.compare(t2.LATEST_RECEIPT, t1.LATEST_RECEIPT) = 0
and t2.ID != t1.ID
-- or if ID isn't unique: and t2.ROWID != t1.ROWID
)
)
where rownumber > 1;
It is of course possible to get a hash collision, and if that happened - you had two latest_receipt values which both appeared more than once and both hashed to the same value - then you could get too many rows back. That seems pretty unlikely, but it's something to consider.
So rather than ordering you can only look for rows which have the same lastest_receipt and a lower ID:
select ID
from your_table t1
where exists (
select null from your_table t2
where dbms_lob.compare(t2.LATEST_RECEIPT, t1.LATEST_RECEIPT) = 0
and t2.ID < t1.ID
);
Again that assumes ID is unique. If it isn't then you could still use rowid instead, but you would have less control over which rows were found - the lowest rowid isn't necessarily the lowest ID. Presumably you're using this to dine rows to delete. If you actually don't mind which row you keep and which you delete then you could still do:
and t2.ROWID < t1.ROWID
But since you are currently ordering that probably isn't acceptable, and hashing might be preferable, despite the small risk.
Example:
It does not work.
UPDATE column_name SET rownum FROM table_name
This work!
UPDATE table_name SET column_name = rownum;
This works but the update is performed incorrectly
SELECT * FROM table_name ORDER BY column_name;
UPDATE table_name SET column_name = rownum;
I wish the following update behavior:
Note:'rownum ' It is not a physical column of the table
/*
pc_comentario = tableName
cod_comentario = columnName (Reference column for sorting)
dtc_andamento = columnDay (Reference column to update the "columnName" according to the order of this column)
*/
rownum | columnName | columnDay
1 1 day 1
2 5 day 5
3 7 day 2
After change with update
rownum | columnName (Update this column) | columnDay (sort by this column)
1 1 day 1
2 2 day 2
3 3 day 5
ALMOST DONE! this column 'cod_comentario_1 "which was materialized in RAM is correct. I need this column" cod_comentario_1 "that does not exist in the table is acknowledged in the consultations with java.
SELECT cod_comentario, dtc_andamento, cod_processo ,
ROW_NUMBER()
OVER (PARTITION BY cod_processo
ORDER BY dtc_andamento) cod_comentario_1
FROM pc_comentario
upadate do not work this way:
UPDATE (
SELECT cod_processo
ROW_NUMBER()
OVER (PARTITION BY cod_processo
ORDER BY dtc_andamento)cod_comentario_1
FROM pc_comentario
) SET cod_comentario_1)
order by Seq
I must enter the values of this consultation in a new column that I created
SELECT
ROW_NUMBER()
OVER (PARTITION BY cod_processo
ORDER BY dtc_andamento DESC)
FROM pc_comentario
Try:
UPDATE table_name
SET column_name = rownum
Shouldn't it be like below rather; I believe UPDATE statement has no FROM clause
UPDATE table_name SET column_name = rownum;
Again, it will work only if rownum is an existing column in your table. If you are trying to use Oracle rownum instead then consider using row_number() function rather
update table_name set column_name =
select rn from ( select column_name, row_number() over (order by column_name) rn
from table_name ) xx;
As you state yourself, rownum is a virtual column. It assigns a sequential value to each row of a particular result set. Which means that the row number of a row could be completely different in the result set of a different query.
If you really want to show the row number as part of the result set, specify it as you would any column:
select rownum as columnName, columnDay
from table
order by ...;
I have 3 Data Table Claim, Part and Labor.
In this Claim is parent table and Part and Labor is mapping tables of Claim and they have Part and Labor has the ClaimId as a Foreign Key.
Claim has data like:
Part has data Like
Labor table has data Like
Target Output would be:
Can anyone help me to achieve this in SQL server.
I have tried to solve with the Union/CTE but it did not gives the result as I want.
I got the same output (for your updated output screen) for this specific case. I don't know if any other data will work for you.
SELECT TMP.ClaimId
, CASE WHEN TMP.RowNum = 1 THEN TMP.Name ELSE NULL END AS ClaimName
, CASE WHEN TMP.RowNum = 1 THEN TMP.Note ELSE NULL END AS Note
, TMP.PartId
, TMP.PartNumber
, TMP.PartCost
, JOIN_L.LaborId
, JOIN_L.LaborCost
FROM (
SELECT C.ClaimId, C.Name, C.Note, P.PartId, P.PartNumber, P.PartCost
, ROW_NUMBER() OVER(PARTITION BY C.ClaimId ORDER BY P.PartId) AS RowNum
FROM Claim AS C
LEFT JOIN Part AS P ON C.ClaimId = P.ClaimId
)AS TMP
LEFT JOIN (
SELECT *
, ROW_NUMBER() OVER(PARTITION BY L.ClaimId ORDER BY L.ClaimId) AS RowNum
FROM Labor AS L
) AS JOIN_L ON (TMP.ClaimId = JOIN_L.ClaimId AND TMP.RowNum = JOIN_L.RowNum)
ORDER BY TMP.ClaimId
Not sure why you tried CTE here
Select C.ClaimId,C.name,C.Note,P.PartId,P.PartNumber,P.PartCost,L.LabourId,L.LabourCost
From Claim C
Left Outer Join Part P On P.ClaimId = C.ClaimId
Left Outer Join Labor L On L.ClaimId=C.ClaimId