How do I LEFT JOIN tables A and B if they can only be connected through a table C?
So the table C includes a linking attribute that connects it with the table A and another attribute that connects it with the table B.
SELECT * FROM TABLE Base base
LEFT JOIN A a ON a.a = base.a
LEFT JOIN C c ON c.c = a.c
LEFT JOIN B b ON b.b = c.b
You could just use two left joins:
SELECT a.*, b.*
FROM a
LEFT JOIN c ON a.id = c.a_id
LEFT JOIN b ON b.id = c.b_id
Related
I want join 6 tables:
Table A join Table B
Table A join Table C
Table A Join Table D
Table D Join Table E
Table E Join Table F
But I can't run it:
SELECT
A.ID, A.Name, A.SName,
B.tel, B.status,
C.ComCode, C.Comdes,
D.Type,
E.Des, E.AreaDes,
F.AreaID
FROM
((((Table A
INNER JOIN
Table B ON A.ID = B.ID)
INNER JOIN
Table C ON A.Concode = C.Comcode)
INNER JOIN
Table D ON A.Type = D.Type)
INNER JOIN
Table E ON D.Des = E.Des)
INNER JOIN
Table F ON E.AreaID = F.AreaID
Get rid of your parentheses and table and it should be vailid SQL, so
SELECT ...
FROM a INNER JOIN b ON a.a = b.a
INNER JOIN c ON b.b = c.a
...
Try this :
SELECT
A.ID, A.Name, A.SName,
B.tel, B.status,
C.ComCode, C.Comdes,
D.Type,
E.Des, E.AreaDes,
F.AreaID
FROM Table A
INNER JOIN Table B ON A.ID = B.ID
INNER JOIN Table C ON A.Concode = C.Comcode
INNER JOIN Table D ON A.Type = D.Type
INNER JOIN Table E ON D.Des = E.Des
INNER JOIN Table F ON E.AreaID = F.AreaID
It will help if you tell us what you database server is e.g., SQL Server, Oracle, MySQL, etc. When you say, "...I can't run it..." are you getting an error? If so, can you share that.
I ditched your parenthesis...
SELECT
A.ID,
A.Name,
A.SName,
B.tel,
B.status,
C.ComCode,
C.Comdes,
D.Type,
E.Des,
E.AreaDes,
F.AreaID
FROM
TableA A INNER JOIN TableB B ON A.ID = B.ID
INNER JOIN TableC C ON A.Concode = C.Comcode
INNER JOIN TableD D ON A.Type = D.Type
INNER JOIN TableE E ON D.Des = E.Des
INNER JOIN TableF F ON E.AreaID = F.AreaID
For clarity, I adjusted your table names (so it was clear what was Table A vs. Table B).
I have two tables Say A and B. A is master table and B is child table, from which I need values as below.
select A.Id, A.Name, B.Path from A,B where A.Id=B.Id
Now, I want to add column of 3rd table which is child of table 'B', say C i.e. C.File.
The value of C.File will be null if C.SubId=B.SubId is false else will return value when condition becomes true.
This is the exact definition of a left join:
SELECT a.id, b.name, b.path, c.file
FROM a
JOIN b ON a.id = b.id
LEFT JOIN c ON b.subid = c.subid
You need to LEFT JOIN your third table from what I can gather.
SELECT A.Id, A.Name, B.Path, C.file
FROM tableA a
INNER JOIN tableB b ON a.id = b.id
LEFT JOIN tableC c ON b.subid = c.subid
Simply Join all the three tables using INNER JOIN
select A.Id, A.Name, B.Path ,C.File
FROM A
INNER JOIN B
ON A.Id=B.Id
INNER JOIN C
ON C.SubId=B.SubId
table A(a_id)
table B (b_id)
table c(c_id , b_id, a_id);
select a.*, b.* , c*
from c join b
i'm confused from here ???
Try this -
SELECT * FROM A
INNER JOIN C
ON A.a_id = C.a_id
INNER JOIN B
ON B.b_id = C.b_id;
SELECT a.*, b.*, c*
FROM c
LEFT JOIN b USING (b_id)
LEFT JOIN a USING (a_id);
Try this
SELECT A.* from tableA A
LEFT JOIN tableC C ON C.a_id = A.a_id
LEFT JOIN tableB B ON C.b_id = B.b_id
You could use INNER, LEFT, RIGHT, FULL... JOINS in following:
SELECT *
FROM A
LEFT JOIN B ON A.a_id = B.b_id
LEFT JOIN C ON B.b_id = C.c_id
I want something like the following.
SELECT fewCols, aColFromNewTbl 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 A.ID = C.ID
INNER JOIN A_NEW_TABLE AS NEWTBL ON NEWTBL.ID = B.ID;
Somehow I'm not able to achieve this functionality. Actually above query is suppose to join A with NEWTBL, but I'm joining it with B, which is already joined with A. For my results I want them to come exclusively from the join of NEWTBL and B. I don't know how I can get desired results?
Probably you need this:
SELECT fewCols, aColFromNewTbl
FROM TABLE_A AS A
LEFT OUTER JOIN TABLE_B AS B
INNER JOIN A_NEW_TABLE AS NEWTBL
ON NEWTBL.ID = B.ID
ON A.ID = B.ID
LEFT OUTER JOIN TABLE_C AS C
ON A.ID = C.ID;
I would like to do something like this but can't get it to work:
SELECT A.*,B.*,C.* FROM tableA A LEFT JOIN
B ON A.ID = B.ID
C ON A.ID = C.ID
I.e. I need to use a field from the first table for all joins as tableB and tableC don't
has any fields to link them together.
Can this be done?
you missed a join !
SELECT A.*,B.*,C.* FROM tableA A
LEFT JOIN
B ON A.ID = B.ID
left join
C ON A.ID = C.ID
Try this one -
SELECT *
FROM dbo.tableA A
LEFT JOIN dbo.B ON A.ID = B.ID
LEFT JOIN dbo.C ON A.ID = C.ID