I have a properly working query
select A.*, B.*
from A left join B on A.id = B.id and B.country = 'USA'
Now with left join I can put only 1 condition ( A.id = B.id). So I have to put B.country = 'USA' part somewhere else. Is there any workaround? I can use subqueries.
Update: I have to work with a framework (DBIx::Class) where I have defined single condition ( Id matching) in Schema and it is not straightforward to alter that.
You could break B into a subquery and filter there instead of at the join
SELECT A.*, B.*
FROM A
LEFT JOIN (
SELECT *
FROM B
WHERE COUNTRY = 'USA'
) B
ON A.ID = B.ID
Related
Given two tables, is there a name for the result of subtracting inner join from full outer join, both on the same condition? Is it a type of "join"? Thanks.
It is not a type of join in SQL. You can write it as:
select . . .
from a full join
b
on a.id = b.id
where a.id is null or b.id is null;
If you are looking for ids that are in only one table, it can be more efficient to do:
select a.id
from a
where not exists (select 1 from b where b.id = a.id)
union all
select b.id
from b
where not exists (select 1 from a where a.id = b.id);
How can I get the red section of the following Venn diagram in SQL
Thanks for your help!
I would think first of except:
select c.*
from c
except
select a.*
from a
except
select b.*
from b;
My next thought would be not exists:
select c.*
from t
where not exists (select 1 from a where a.id = c.id) and
not exists (select 1 from b where b.id = c.id);
Using Joins you can get any portion of Ven diagram, Somethink like below for your scenario.
select c.*
from TableC c
left join TableA a on a.id = c.id
left join TableB b on b.id = c.id
Where a.id is null and b.id is null -- Records which does not match in both tables
Well there is gonna be a bit of handwaving considering you are not giving actual table structures, but something like this:
Select c.name
From c
Where not exists (select 1 from b where b.id = c.id)
And not exists (select 1 from a where a.id = c.id);
You can use NOT IN (assuming id is the common attribute):
SELECT c.id FROM c
WHERE c.id NOT IN (SELECT a.id FROM a)
AND c.id NOT IN (SELECT b.id FROM b);
I've got two queries that return single result.
They look something like this
// query 1
SELECT A.id FROM tableA A
INNER JOIN tableB B
ON B.id = A.id
WHERE b.status = 'ACTIVE'
// query 2
SELECT C.id FROM tableC C
WHERE c.status = 'ACTIVE'
How to combine them and make return the pair of values instead of one value from different queries? I mean to get something like [A.id, C.id]
Currently I have to use two queries in the applications and I want to combine them into one.
I think like this will do
SELECT (SELECT A.id FROM tableA A
INNER JOIN tableB B
ON B.id = A.id
WHERE b.status = 'ACTIVE'
) as 'query1',
(
SELECT C.id FROM tableC C
WHERE c.status = 'ACTIVE'
) as 'query2'
As your question is not clear, so i assume that you either needids from mentioned queries in one row or in different rows, you can use union all/union (provided that datatypes are compatible or implicitly convertible and duplicates or allowed or not) as below.
Combining Result in different rows.
SELECT A.id
FROM tableA A
INNER JOIN tableB B
ON B.id = A.id
WHERE b.status = 'ACTIVE'
union all
SELECT C.id
FROM tableC C
WHERE c.status = 'ACTIVE'
Combining Result in Single Row.
select max(id1), max(id2)
from(
SELECT A.id as id1, NULL as id2
FROM tableA A
INNER JOIN tableB B
ON B.id = A.id
WHERE b.status = 'ACTIVE'
union all
SELECT NULL, C.id
FROM tableC C
WHERE c.status = 'ACTIVE'
) t;
SAMPLE DEMO
You can run following query which work fine for me:
select t1.id as aid ,t2.id as cid
from (
SELECT A.id
FROM tableA A
INNER JOIN tableB B ON B.id = A.id
WHERE b.status = 'ACTIVE'
) t1
full outer join (
SELECT C.id
FROM tableC C
WHERE c.status = 'ACTIVE'
) t2 on t1.id=t2.id
You can join your second query with your first query as follows, so that you will get two (A.id, C.id) values in one query...
SELECT A.ID,C.ID FROM
(SELECT A.ID FROM table_A A INNER JOIN
table_B B ON A.ID=B.ID WHERE B.STATUS='A')A
INNER JOIN table_c C
ON C.ID=A.ID WHERE C.STATUS='A';
Working on Oracle: I am attempting to do an inner self join, with a where clause, then take that result and do a left outer join on it:
(select * from table1 A
inner join
select * from table1 B
on A.id = B.id
where
A.id is not null and B.id is not null) C
left outer join
select * from table2 D
on C.id = D.id
Somehow I am syntactically challenged and can't make this work. Can't seem to find the right syntax anywhere.
Just the put the where clause at the end. The database will get it right:
select *
from table1 A
inner join table1 B on A.id = B.id
left join table2 D on D.id = A.id
where A.id is not null
In this case, we can take advantage of the logical transitive property for your id column joins and where clause.
Your second join needs to be joined to a query add a select * from at the beginning
select * from (select * from table1 A
inner join
select * from table1 B
on A.id = B.id
where
A.id is not null and B.id is not null) C
left outer join
select * from table2 D
on C.id = D.id
I have table A, B and C
I want to return all entries in table A that do not exist in table B and of that list do not exist in table C.
select * from table_A as a
where not exists (select 1 from table_B as b
where a.id = b.id)
this gives me the first result of entries in A that are not in B. But now I want only those entries of this result that are also not in C.
I tried flavours of:
select * from table_A as a
where not exists (select 1 from table_B as b
where a.id = b.id)
AND
where not exists (select 1 from table_C as c
where a.id = c.id)
But that isnt the correct logic. If there is a way to store the results from the first query and then select * from that result that are not existent in table C. But I'm not sure how to do that. I appreciate the help.
Try this:
select * from (
select a.*, b.id as b_id, c.id as c_id
from table_A as a
left outer join table_B as b on a.id = b.id
left outer join table_C as c on c.id = a.id
) T
where b_id is null
and c_id is null
Another implementation is this:
select a1.*
from table_A as a1
inner join (
select a.id from table_A
except
select b.id from table_B
except
select c.id from table_c
) as a2 on a1.id = a2.id
Note the restrictions on the form of the sub-query as described here. The second implementation, by most succinctly and clearly describing the desired operation to SQL Server, is likely to be the most efficient.
You have two WHERE clauses in (the external part of) your second query. That is not valid SQL. If you remove it, it should work as expected:
select * from table_A as a
where not exists (select 1 from table_B as b
where a.id = b.id)
AND
not exists (select 1 from table_C as c -- WHERE removed
where a.id = c.id) ;
Tested in SQL-Fiddle (thnx #Alexander)
how about using LEFT JOIN
SELECT a.*
FROM TableA a
LEFT JOIN TableB b
ON a.ID = b.ID
LEFT JOIN TableC c
ON a.ID = c.ID
WHERE b.ID IS NULL AND
c.ID IS NULL
SQLFiddle Demo
One more option with NOT EXISTS operator
SELECT *
FROM dbo.test71 a
WHERE NOT EXISTS(
SELECT 1
FROM (SELECT b.ID
FROM dbo.test72 b
UNION ALL
SELECT c.ID
FROM dbo.test73 c) x
WHERE a.ID = x.ID
)
Demo on SQLFiddle
Option from #ypercube.Thank for the present;)
SELECT *
FROM dbo.test71 a
WHERE NOT EXISTS(
SELECT 1
FROM dbo.test72 b
WHERE a.ID = b.ID
UNION ALL
SELECT 1
FROM dbo.test73 c
WHERE a.ID = c.ID
);
Demo on SQLFiddle
I do not like "not exists" but if for some reason it seems to be more logical to you; then you can use a alias for your first query. Subsequently, you can re apply another "not exists" clause. Something like:
SELECT * FROM
( select * from tableA as a
where not exists (select 1 from tableB as b
where a.id = b.id) )
AS A_NOT_IN_B
WHERE NOT EXISTS (
SELECT 1 FROM tableC as c
WHERE c.id = A_NOT_IN_B.id
)