This is probably a really easy question, it's just very hard to google a word like "All".
SELECT a.Id, Max(b.Number)
FROM Table1 a
JOIN Table2 b
ON a.FK = b.Id
GROUP BY a.Id
But I want to add a where clause that specifies that all b.Id's linked to an a.FK must have values. So basically I don't want to select the a.Id grouping of b.Id's where any of those b.Id's are null. Hope I made that clear, let me know if I need to elaborate. Thanks.
Edit - For some clarification (Changed the query above as well):
Table1
Id, FK
1 1
1 2
2 3
3 4
3 5
3 6
Table 2
Id Number
1 1
2 NULL
3 10
4 20
5 30
6 40
I would want my query to show:
a.Id Max Number
2 10
3 40
(Notice that a.Id = 1 doesn't show up because one of the b.Number fields is null)
select t1.Id, max(Number) as [Max Number]
from Table1 t1
left join Table2 t2 ON t1.FK=t2.Id and t2.Number is not null
group by t1.Id
having count(distinct t1.FK) = count(distinct t2.Id)
Okay, you are asking a totally different question from the one I thought you were. I'm replacing my answer.
The way I would handle this is to join a to b twice -- once to get all matching rows in b, and a second join to search for rows in b where Number is null. If no such row exists, then we know they're all non-null.
SELECT a.Id, Max(b1.Number)
FROM Table1 a
JOIN Table2 b1 ON a.FK = b1.Id
LEFT OUTER JOIN Table2 b2 ON a.FK = b2.Id AND b2.Number IS NULL
WHERE b2.Id IS NULL
GROUP BY a.Id
b2.Id will be null only if no row is found where b2.Number is null.
SELECT a.Id, Max(b.Id)
FROM Table1 a
JOIN Table2 b
ON a.FK = b.Id
WHERE b.Id is NOT NULL
GROUP BY a.Id
Related
In SQL I am trying to combine create a column id_main2 (after a right join) that is equal the value of column id_main (coming from a) if not NULL and the value of id (coming from b) if id_main is NULL.
Below is the join code followed by the desired output. How can I create this id_main2 column?
SELECT * FROM a
RIGHT JOIN b on a.id = b.id;
id_main id boy id girl id_main2
10 1 Alex 1 Alice 10
11 2 Bruce 2 Brunet 11
NULL NULL NULL 5 Emma 5
NULL NULL NULL 6 Fabia 6
I think you just want coalesce():
select a.*, b.*,
coalesce(a.id_main, b.id)
from b left join
a
on a.id = b.id;
I strongly prefer left join to right join, so I rearranged the tables in the from clause.
You can either use coalesce()
select
coalesce(a.id_main, b.id) as id_main2
from a
right join b on a.id = b.id;
or case when
select
case when a.id is not null then a.id
else b.id end as id_main2
from a
right join b on a.id = b.id;
I'm struggling getting this query to produce the results I want.
I have:
table1, columns=empid, alt_id
table2, columns=empid, alt_id
I want to get the empid, and alt_id from table 1 where the alt_id does not match the alt_id in table2. They will both have alt_id numbers I just want to get the ones that do not match.
Any ideas?
SELECT * FROM table1
INNER JOIN table2 ON table2.empid = table1.empid AND table2.alt_id <> table1.alt_id
What does that really mean though? Normally when this is asked, it is of the form "I want all rows from A that have no row matching in B and all in B that have no match in A"
Which looks like this:
SELECT * FROM
A
FULL OUTER JOIN
B
ON
a.id = b.id
You'll see a null for any row data where there isn't a matching row on the other side:
A.id
1
2
B.id
1
3
Result of full outer join:
A.id B.id
1 1
2 null
null 3
You, however have asked for A-B join where the IDs aren't equal, which would be the more useless query of:
SELECT * FROM
A
INNER JOIN
B
ON
a.id != b.id
And it would look like:
A.id B.id
1 3
2 1
2 3
You seem to want not exists:
select t1.*
from table1 t1
where not exists (select 1 from table2 t2 where t2.alt_id = t1.alt_id);
It is unclear whether or not you also want to join on empid, so you might really want:
select t1.*
from table1 t1
where not exists (select 1 from table2 t2 where t2.alt_id = t1.alt_id and t2.empid = t1.empid);
A left join will find all records in Table A that do not match those in Table B. Then use a Where filter to find the Nulls from Table B. That will give you all those in Table A that do not have a matching ID in Table B.
Select A.*
from Table A
Left Join
Table B
on a.altid = b.altid
where b.altid is null;
select *
from [Login] L inner join Employee E
on l.EmployeeID = e.EmployeeID
where l.EmployeeID not in (select EmployeeID from Employee)
I have a table name "a"
Id name
1 abc
2 xyz
3 mmm
4 xxx
and Other table name is "b"
Id suId
3 2
3 1
My requirement is get detail from "a" table from "b" table where id=3. Any help?
SELECT a.Id, a.name, b.Id, b.suId FROM b JOIN a ON b.suId = a.Id WHERE b.Id = 3;
I wont recommend join for this kind of scenarios(you want all details from Table A whose ids are in Table B suId column, where Table B id should be 3., Its bad English but hope you got me and may be i got you too.)
SELECT a.name FROM a
WHERE
a.id IN(SELECT b.suId FROM b WHERE b.id = 3);
If you want to use join only then,
SELECT a.name FROM a,b
WHERE a.id = b.suId
AND
b.id = 3;
Simple answer:
SELECT a.Id,a.name FROM a,b
WHERE a.Id=b.suId AND b.Id=3
It will give you the result:
Id Name
1 abc
2 xyz
See result in SQL Fiddle
This should get the job done:
SELECT * FROM table_a a JOIN table_b b ON b.suId = a.Id WHERE b.Id = 3;
You can try this...You can try different JOIN clauses like INNER JOIN, LEFT OUTER JOIN or just simply JOIN etc. You will get different number of rows depending on field connections from 1 table to the other.
SELECT T1.*
FROM a T1
INNER JOIN b T2
ON T1.Id = T2.Id
WHERE T1.Id='3'
In where clause I have
Select B.ID,
B.TIME_1,
B.TIME_2,
a.event_type,
a.jew,
c.dist
from B, table1 a left outer join table3 c on a.jew = c.mew
Where B.ID = A.ID
AND a.event_type in ('APPLE','ORANGE','GRAPE')
My Problem is my querty doesn't show if for example some records of ID doesn't all 3 (apple,orange,grape). I would still like to pull all ID even if it doesn't have all 3 or none of Apple orange, Grape.
Example:
Lets say my database has total of 5 records
ID=1 has event type of Apple, Orange, Grape also has none but it has others also I don't care about it
ID=2 Apple
ID=3 Orange
ID=4 Apple,Orange Grape
ID=5 none of 3 but others I don't care about
So currently my query is just pulling where ID=1, I want to modify where it pulls all 5 condition.
You want any of the three event types or none. For this, use left outer joins but put all the conditions in the on clause:
SELECT B.ID, B.TIME_1, B.TIME_2, A.event_type, A.jew, C.dist
FROM B left outer join
table1 A
ON B.ID = A.ID and
A.event_type in ('APPLE','ORANGE','GRAPE') LEFT OUTER JOIN
table3 C
ON A.jew = C.mew
You need to do a left join also with your table1, and add a condition in case there is no match between B and table1:
SELECT B.ID,
B.TIME_1,
B.TIME_2,
A.event_type,
A.jew,
C.dist
FROM B
LEFT OUTER JOIN table1 A
ON B.ID = A.ID
LEFT OUTER JOIN table3 C
ON A.jew = C.mew
WHERE A.event_type IS NULL
OR A.event_type in ('APPLE','ORANGE','GRAPE')
Suppose we have a table A:
itemid mark
1 5
2 3
and table B:
itemid mark
1 3
3 5
I want to join A*B on A.itemid=B.itemid both right and left ways. i.e. result:
itemid A.mark B.mark
1 5 3
2 3 NULL
3 NULL 5
Is there a way to do it in one query in MySQL?
It's called a full outer join and it's not supported natively in MySQL, judging from its docs. You can work around this limitation using UNION as described in the comments to the page I linked to.
[edit] Since others posted snippets, here you go. You can see explanation on the linked page.
SELECT *
FROM A LEFT JOIN B ON A.id = B.id
UNION ALL
SELECT *
FROM A RIGHT JOIN B ON A.id = B.id
WHERE A.id IS NULL
Could do with some work but here is some sql
select distinct T.itemid, A.mark as "A.mark", B.mark as "B.mark"
from (select * from A union select * from B) T
left join A on T.itemid = A.itemid
left join B on T.itemid = B.itemid;
This relies on the left join, which returns all the rows in the original table (in this case this is the subselect table T). If there are no matches in the joined table, then it will set the column to NULL.
This works for me on SQL Server:
select isnull(a.id, b.id), a.mark, b.mark
from a
full outer join b on b.id = a.id