I inserted all the rows of a view to a delta table, but after running a query for a particular value I get below results.
Can someone explain to me how this is possible?
A is View and B is Delta(databricks) table.
1.
Select count(*) from A
result: 102.321
2.
Select * from A where id = '11'
id
date
unit
11
2022-09-02
4
3.
Insert Into B Select * From A
OR
CREATE OR REPLACE TABLE B AS ( SELECT * FROM A)
Select count(*) from B '
result: 101.372
5.
Select * from B where id = '11'
id
date
unit
11
2022-09-02
2
Need help in optimizing SQL query, I have figured a way to solve the problem by using UNIONALL, but my worry is that performance will be impacted as the record set is huge in production env.
I have a table of records in below format, I need help in retrieving the non-null entries if available otherwise pick the null entries.
In the below case; Query should exclude RowIds 1,7 and retrieve everything else, i.e because there are non-null entries for that combination.
RowID
UniqueID
TrackId
1
325
NULL
2
325
8zUAC
3
325
99XER
4
427
NULL
5
632
2kYCV
6
533
NULL
7
774
NULL
8
774
94UAC
--UNIONALL Command
SELECT A.* FROM
( SELECT * FROM [MY_PKG].[TEMP] WHERE TRACKID is not null) A
WHERE A.UNIQUEID in
( SELECT UNIQUEID FROM [MY_PKG].[TEMP] WHERE TRACKID is null
)
UNION ALL
SELECT B.* FROM
( SELECT * FROM [MY_PKG].[TEMP] WHERE TRACKID is null) B
WHERE B.UNIQUEID not in
( SELECT UNIQUEID FROM [MY_PKG].[TEMP] WHERE TRACKID is not null
)
Temp Table Creation Scrip
CREATE TABLE MY_PKG.TEMP
( UNIQUEID varchar(3),
TRACKID varchar(5)
);
INSERT INTO MY_PKG.TEMP
( UNIQUEID, TRACKID)
VALUES
('325',null),
('325','8zUAC'),
('325','99XER'),
('427',null),
('632','2kYCV'),
('533','2kYCV'),
('774',null),
('774','94UAC')
You can use the NOT EXISTS operator with a correlated subquery:
SELECT * FROM TEMP T
WHERE TRACKID IS NOT NULL
OR (TRACKID IS NULL
AND NOT EXISTS(
SELECT 1 FROM TEMP D
WHERE D.UNIQUEID = T.UNIQUEID AND
D.TRACKID IS NOT NULL)
)
See demo
I have a query that vertically expands data by using Union condition. Below are the 2 sample tables:
create table #temp1(_row_ord int,CID int,_data varchar(10))
insert #temp1
values
(1,1001,'text1'),
(2,1001,'text2'),
(4,1002,'text1'),
(5,1002,'text2')
create table #temp2(_row_ord int,CID int,_data varchar(10))
insert #temp2
values
(1,1001,'sample1'),
(2,1001,'sample2'),
(4,1002,'sample1'),
(5,1002,'sample2')
--My query
select * from #temp1
union
select * from #temp2 where CID in (select CID from #temp1)
order by _row_ord,CID
drop table #temp1,#temp2
So my current output is:
I want to group the details of every client together for which I am unable to use 'where' clause across Union condition.
My desired output:
Any help?! Order by is also not helping me.
I can imagine you want all of the rows for a CID sorted by _row_ord from the first table before the ones from the second table. And the CID should be the outermost sort criteria.
If that's right, you can select literals from your tables. Let the literal for the first table be less than that of the second table. Then first sort by CID, then that literal and finally by _row_ord.
SELECT cid,
_data
FROM (SELECT 1 s,
_row_ord,
cid,
_data
FROM #temp1
UNION ALL
SELECT 2 s,
_row_ord,
cid,
_data
FROM #temp2) x
ORDER BY cid,
s,
_row_ord;
db<>fiddle
If I correctly understand your need, you need the output to be sorted the way that #temp1 rows appear before #temp2 rows for each cid value.
What you could do is generate additional column ordnum assigning values for each table, just for sorting purposes, and then get rid of it in the outer select statement.
select cid, _data
from (
select 1 as ordnum, *
from #temp1
union all
select 2 as ordnum, *
from #temp2 t2
where exists (
select 1
from #temp1 t1
where t1.cid = t2.cid
)
) q
order by cid, ordnum
I have also rewritten your where condition for an equivalent which should work faster using exists operator.
Live DEMO - click me!
Output
cid _data
1001 text1
1001 text2
1001 sample1
1001 sample2
1002 text1
1002 text2
1002 sample1
1002 sample2
Use With. here is my first try with your sql
create table #temp1(_row_ord int,CID int,_data varchar(10))
insert #temp1
values
(1,1001,'text1'),
(2,1001,'text2'),
(4,1002,'text1'),
(5,1002,'text2')
create table #temp2(_row_ord int,CID int,_data varchar(10))
insert #temp2
values
(1,1001,'sample1'),
(2,1001,'sample2'),
(4,1002,'sample1'),
(5,1002,'sample2');
WITH result( _row_ord, CID,_data) AS
(
--My query
select * from #temp1
union
select * from #temp2 where CID in (select CID from #temp1)
)
select * from tmp order by CID ,_data
drop table #temp1,#temp2
result
_row_ord CID _data
1 1001 sample1
2 1001 sample2
1 1001 text1
2 1001 text2
4 1002 sample1
5 1002 sample2
4 1002 text1
5 1002 text2
Union is placed between two result set blocks and forms a single result set block. If you want a where clause on a particular block you can put it:
select a from a where a = 1
union
select z from z
select a from a
union
select z from z where z = 1
select a from a where a = 1
union
select z from z where z = 1
The first query in a union defines column names in the output. You can wrap an output in brackets, alias it and do a where on the whole lot:
select * from
(
select a as newname from a where a = 1
union
select z from z where z = 2
) o
where o.newname = 3
It is important to note that a.a and z.z will combine into a new column, o.newname. As a result, saying where o.newname will filter on all rows from both a and z (the rows from z are also stacked into the newname column). The outer query knows only about o.newname, it knows nothing of a or z
Side note, the query above produces nothing because we know that only rows where a.a is 1 and z.z is 2 are output by the union as o.newname. This o.newname is then filtered to only output rows that are 3, but no rows are 3
select * from
(
select a as newname from a
union
select z from z
) o
where o.newname = 3
This query will pick up any rows in a or z where a.a is 3 or z.z is 3, thanks to the filtering of the resulting union
I think this requirement is rarely encountered so I couldn't search for similar questions.
I have a table that needs to update the ID. For example ID 123 in table1 is actually supposed to be 456. I have a separate reference table built that stores the mapping (e.g. old 123 maps to new id 456).
I used the below query but apparently it returned error 38104, columns referenced in the ON clause cannot be updated.
MERGE INTO table1
USING ref_table ON (table1.ID = ref_table.ID_Old)
WHEN MATCHED THEN UPDATE SET table.ID = ref_table.ID_New;
Is there other way to achieve my purpose?
Thanks and much appreciated for your answer!
Use the ROWID pseudocolumn:
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE TABLE1( ID ) AS
SELECT 1 FROM DUAL UNION ALL
SELECT 2 FROM DUAL UNION ALL
SELECT 3 FROM DUAL;
CREATE TABLE REF_TABLE( ID_OLD, ID_NEW ) AS
SELECT 1, 4 FROM DUAL UNION ALL
SELECT 2, 5 FROM DUAL;
MERGE INTO TABLE1 dst
USING ( SELECT t.ROWID AS rid,
r.id_new
FROM TABLE1 t
INNER JOIN REF_TABLE r
ON ( t.id = r.id_old ) ) src
ON ( dst.ROWID = src.RID )
WHEN MATCHED THEN
UPDATE SET id = src.id_new;
Query 1:
SELECT * FROM table1
Results:
| ID |
|----|
| 4 |
| 5 |
| 3 |
You can't update a column used in the ON clause in a MERGE. But if you don't need to make other changes that MERGE allows like WHEN NOT MATCHED or deleting, etc. you can just use a UPDATE to achieve this.
You mentioned this is an ID that needs an update. Here's an example using a scalar subquery. As it is an ID, this presumes UNIQUE ID_OLD values in REF_TABLE. I wasn't sure if Every row needs an update or only a sub-set, so set the update here to only update rows that have a value in REF_TABLE.
CREATE TABLE TABLE1(
ID NUMBER
);
CREATE TABLE REF_TABLE(
ID_OLD NUMBER,
ID_NEW NUMBER
);
INSERT INTO TABLE1 VALUES (1);
INSERT INTO TABLE1 VALUES (2);
INSERT INTO TABLE1 VALUES (100);
INSERT INTO REF_TABLE VALUES (1,10);
INSERT INTO REF_TABLE VALUES (2,20);
Initial State:
SELECT * FROM TABLE1;
ID
1
2
100
Then make the UPDATE
UPDATE TABLE1
SET TABLE1.ID = (SELECT REF_TABLE.ID_NEW
FROM REF_TABLE
WHERE REF_TABLE.ID_OLD = ID)
WHERE TABLE1.ID IN (SELECT REF_TABLE.ID_OLD
FROM REF_TABLE);
2 rows updated.
And check the change:
SELECT * FROM TABLE1;
ID
10
20
100
I am writing a query in which where clause have IN clause and there are large number of values in this IN clause , I want to fetch the result such that if there is no value exist in table for value given in IN clause then a raw containing 0 or null should return for that value. for example..
select age,sex,date_joining from emp where name IN ('amit','john','paul','dilip')
Now assume for this query ,data for john and paul does not exist in database then result should be like below..
21 male 21-AUG-2011
null null null
null null null
25 male 9-aug-2010
we can also have 0 instead of null if null is not possible
Thanks...
select filter.name
, emp.age
, emp.sex
, emp.date_joining
from (
values ('amit'), ('john'), ('paul'), ('dilip')
) filter(name)
left join
emp
on emp.name = filter.name
Live example at SQL Fiddle.
For older values of SQL Server, replace the line with values by:
from (
select 'amit'
union all select 'john'
union all select 'paul'
union all select 'dilip'
) filter(name)
You can also use common table expression to get this result:
;With AllEmpDetails as
(
Select [Name] from emp
UNION Select 'amit'
UNION Select 'john'
UNION Select 'paul'
UNION Select 'dilip'
)Select AllEmpDetails.Name, e2.Age, e2.Sex, e2.date_joining
from AllEmpDetails
Left Join emp e2 on e2.[Name] = AllEmpDetails.Name
In my database, I have already added details for amit and dilip so i have used UNION since you can easily get the detail about the available employees. On the other hand you can use UNION ALL with Distinct.