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'
Related
I have two tables like this :
TableA
Id | ProjectId | JobId
TableB
Id | Title
I want to write a query returning TableB Ids that are not in TableA with ProjectId = 2.
I've written a query like
Select B.Id
From TableB B
Right Join TableA A On B.Id = A.JobId
Where B.JobId Is Null And A.ProjectId = 2
But it returns zero output.
Thanks
I would use EXISTS here:
SELECT b.Id
FROM TableB b
WHERE NOT EXISTS (SELECT 1 FROM TableA a WHERE a.JobId = b.Id AND a.ProjectId = 2);
Reading in English terms, the above says to select every Id in TableB such that we cannot find an equal Id in TableA whose ProjectId is also 2.
Query edited
I have two tables:
Table A:
id names
1 a
2 b
3 c
and Table B:
id names
1 x
2 y
I'd like to perform a left join of Table B on Table A that results in the following table:
id names
1 x
2 y
3 c
How can I do this in Microsoft SQL?
You could use COALESCE:
SELECT a.id, COALESCE(b.name, a.name) AS name
FROM tab1 a
LEFT JOIN tab2 b
ON a.id = b.id
I think you just want coalesce():
select a.id, coalesce(b.name, a.name) as name
from a left 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 next tables.
First one is A.
A have two columns: A_ID and A_VALUE.
Second table is B. B too have two columns: B_ID and B_VALUE
In additional I have table C. Table C have C_ID and bool columns C_BOOL
If C_BOOL value == true i need select value from A with given ID.
If C_BOOL value == false i need select value from B.
How I can write SELECT for this?
I use oracle db.
Thanks in advice.
SELECT CASE C.BOOL WHEN 1 THEN A.ID ELSE B.ID END
FROM A
JOIN B
ON B.ID = A.ID
JOIN C
ON C.ID = A.ID
Try this query:
SELECT C_ID,CASE WHEN C_BOOL = 1 THEN T3.A_VALUE ELSE T2.B_VALUE END
FROM TABLE_C T1 LEFT OUTER JOIN TABLE_B T2 ON T1.C_ID = T2.B_ID
LEFT OUTER JOIN TABLE_A T3 T2 ON T1.C_ID = T3.A_ID
select decode(C.BOOL,1,A.ID,B.ID) FROM C
JOIN A
ON A.ID=C.ID
JOIN B
ON B.ID=C.ID;
I consider T McKeown answer as valid this is just equivalent (but more compact) I suppose.
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