How can I convert this subquery to join query or something more simple like with?
SELECT *
FROM ViewBuy99
WHERE Id NOT IN (
SELECT Id
FROM Buy99
)
INSERT INTO Buy99
SELECT *
FROM ViewBuy99
WHERE Id NOT IN (
SELECT Id
FROM Buy99
)
You can express this using JOIN as:
insert into Buy99
select vb.*
from ViewBuy99 vb left join
Buy99 b
on b.id = vb.id
where b.id is null;
However, I would recommend NOT EXISTS:
insert into Buy99
select vb.*
from ViewBuy99 vb
where not exists (select 1
from Buy99 b
where b.id = vb.id
);
Related
I have two table in my same DB
create table a(gr_code nvarchar, code int)
insert into a values('1',100),('0',200),('1',200),('0',100)
create table b(gr_code nvarchar, code int)
insert into b values('1',100),('0',200)
find the code in table A which does not have in table B for particular gr_code
expected result:
gr_code code
1 200
0 100
It's quite simple using the clause exists
select *
from a
where not exists (select *
from b
where b.gr_code = a.gr_code and
b.code = a.code)
This returns the result on your sample.
Use LEFT JOIN
select a.*
from a
left join b on a.gr_code = b.gr_code and a.code = b.code
where b.gr_code is null
You can use LEFT JOIN like this:
SELECT a.*
FROM a
LEFT JOIN b on a.gr_code = b.gr_code
WHERE b.gr_code IS NULL
You can use EXCEPT like so:
select *
from a
except
select *
from b
Please explain to me the use of the comma after 'FROM TABLE_ABC A'. how does it work in the execution of the sql query.
CREATE TABLE ABCD AS
( SELECT A.*
FROM TABLE_ABC A,
(SELECT COL_1,COL_2 FROM
(SELECT B.*,C.* FROM
TABLE_XYZ B, TABLE_MNO C
WHERE B.COL_X=C.COL_Y
)D
)A.COL_C=D.COL_D
)
WITH DATA PRIMARY INDEX(SASAJS)
It is similar to join
select * from #tempA ta join #tempB tb
on ta.ID = tb.ID
same as
select * from #tempA ta, #tempB tb
where ta.ID = tb.ID
Using JOINS makes the code easier to read
You're using a select to create a 2nd table that is also created from another subselect. See it like this and you'll understand it better:
CREATE TABLE ABCD AS(
SELECT
A.*
FROM
TABLE_ABC A,
(
SELECT
COL_1,
COL_2
FROM
(
SELECT
B.*,
C.*
FROM
TABLE_XYZ B,
TABLE_MNO C
WHERE
B.COL_X = C.COL_Y
) D
)
WHERE
A.COL_C = D.COL_D
) WITH DATA PRIMARY INDEX(SASAJS)
but your original code is lacking a WHERE CLAUSE before A.COL_C = D.COL_D. I included it.
I'm assuming that B.* or C.* has a column named COL_D AND A also has it. It would also be better if the D as after the ) before the last WHERE
I've got a table with > 1'000'000 entries; this table is referenced from about 130 other tables. My problem is that a lot of those 1-mio-entries is old and unused.
What's the fastet way to find the entries not referenced by any of the other tables? I don't like to do a
select * from (
select * from table-a TA
minus
select * from table-a TA where TA.id in (
select "ID" from (
(select distinct FK-ID "ID" from table-b)
union all
(select distinct FK-ID "ID" from table-c)
...
Is there an easier, more general way?
Thank you all!
You could do this:
select * from table_a a
where not exists (select * from table_b where fk_id = a.id)
and not exists (select * from table_c where fk_id = a.id)
and not exists (select * from table_d where fk_id = a.id)
...
try :
select a.*
from table_a a
left join table_b b on a.id=b.fk_id
left join table_c c on a.id=c.fk_id
left join table_d d on a.id=d.fk_id
left join table_e e on a.id=e.fk_id
......
where b.fk_id is null
and c.fk_id is null
and d.fk_id is null
and e.fk_id is null
.....
you might also try:
select a.*
from table_a a
left join
(select b.fk_id from table_b b union
select c.fk_id from table_c c union
...) table_union on a.id=table_union.fk_id
where table_union.fk_id is null
This is more SQL oriented and it will not take forever like the above solution.
Not sure about efficiency but:
select * from table_a
where id not in (
select id from table_b
union
select id from table_c )
If your concern is allowing the database to continue normal operations while you do the house keeping you could split it into multiple stages:
insert into tblIds
select id from table_a
union
select id from table_b
as may times as you need and then:
delete * from table_a where id not in ( select id from tableIds )
Of course sometimes doing a lot of processing takes a lot of time.
I like #Patrick's answer above, but I would like to add to that.
Rather than building the 130-step query by hand, you could build these INSERT statements by scanning sysObjects, finding key relations and generating your INSERT statements.
That would not only save you time, but should also help you to know for sure whether you've covered all the tables - maybe there are 131, or only 129.
I'm inclined to Marcelo Cantos' answer (and have upvoted it), but here is an alternative in an attempt to circumvent the problem of not having indexes on the foreign keys...
WITH
ids_a AS
(
SELECT id FROM myTable
)
,
ids_b AS
(
SELECT id FROM ids_a WHERE NOT EXISTS (SELECT * FROM table_a WHERE fk_id = ids_a.id)
)
,
ids_c AS
(
SELECT id FROM ids_b WHERE NOT EXISTS (SELECT * FROM table_b WHERE fk_id = ids_b.id)
)
,
...
,
ids_z AS
(
SELECT id FROM ids_y WHERE NOT EXISTS (SELECT * FROM table_y WHERE fk_id = ids_y.id)
)
SELECT * FROM ids_z
All I'm trying to do is to suggest an order to Oracle to minimise its efforts. Unfortunately Oracle will compile this to comething very similar to Marcelo Cantos' answer and it may not performa any differently.
I have a table containing a unique ID field. Another field (REF) contains a reference to another dataset's ID field.
Now I have to select all datasets where REF points to a dataset that doesn't exist.
SELECT * FROM table WHERE ("no dataset with ID=REF exists")
How can I do this?
3 ways
SELECT * FROM YourTable y WHERE NOT EXISTS
(SELECT * FROM OtherTable o WHERE y.Ref = o.Ref)
SELECT * FROM YourTable WHERE Ref NOT IN
(SELECT Ref FROM OtherTable WHERE Ref IS NOT NULL)
SELECT y.* FROM YourTable y
LEFT OUTER JOIN OtherTable o ON y.Ref = o.Ref
WHERE o.Ref IS NULL
See also Five ways to return all rows from one table which are not in another table
Try this:
SELECT * FROM TABLE WHERE NOT EXISTS
(SELECT * FROM OtherTable WHERE TABLE.Ref = OtherTable.ID)
I think this should work
SELECT * FROM table WHERE id NOT IN (SELECT ref_id FROM ref_table)
or with JOIN
SELECT table.*
FROM table LEFT JOIN ref_table ON table.id = ref_table.ref_id
WHERE ref_table.ref_id IS NULL
SELECT
table1.*
FROM
table1
LEFT JOIN table2 ON table1.id = table2.ref
WHERE
table2.ref IS NULL
You can do a subquery like:
select * from table where somefield not in (select otherfield from sometable where ID=REF)
SELECT *
FROM table
WHERE ((SELECT COUNT(*) FROM table2 WHERE table2.id = table.ref) = 0)
Something like that :
SELECT * FROM table WHERE ID NOT IN(SELECT REF FROM Table2 )
Yes you can use
select * from x where not exist ( select * from y )
SELECT *
INTO Temp3
from
( SELECT B.Name
FROM [Temp2] as B
WHERE B.Name
Not IN (
SELECT E.WorkerName
FROM WorkerDetail as E ) )
Why does this produce an error?
If you want to use a derived table you need to alias it:
SELECT T1.*
INTO Temp3
from
( SELECT B.Name
FROM [Temp2] as B
WHERE B.Name
Not IN (
SELECT E.WorkerName
FROM WorkerDetail as E ) ) AS T1
I'm not sure if you actually need to use a derived table, however.
This should also work:
SELECT B.Name
INTO Temp3
FROM [Temp2] as B
WHERE B.Name
Not IN (
SELECT E.WorkerName
FROM WorkerDetail as E )
Maybe Temp3 already exists?
In MSSQL SELECT..INTO used to populate new table with data.
If this table exist, you can use INSERT INTO .. SELECT FROM statement.