I have 2 Tables, that related with third by one-to-many relation.
For example I have Table A, Table B and Table C.
Table A and B related with table C as many-to-one. So in Table C I have 2 fields like tableAId and tableBId. As a result I need to find a list which includes all Elements from table C which related with table A and compare them to all elements from table C which related with table B.
I tried do it with except, minus statements, but it works incorrect.
Here is what I try to do:
SELECT tableAId FROM tableC
except
select tableBId FROM tableC
UPDATE
Here is my 3 tables :enter image description here
I'm not 100% following what you require but i think below is what you want
SELECT a.ID, b.ID
FROM TableA a
JOIN TableC c ON a.ID = c.TableCID
JOIN TableB b ON c.TableBID = b.ID
Related
I am not sure if this can be done with a single JOIN, but I basically have two tables with an ID column in common. To make it simple I'll say Table A just contains an ID while Table B contains an ID and Code. There is a 1:M relationship between Table A and Table B, however it's also possible an ID from Table A is not contained in Table B at all. I was hoping to have a query return every ID that exists in Table B within a particular code range, or does not exist in Table B at all.
I tried using a LEFT JOIN with something like:
SELECT A.id FROM A LEFT JOIN B ON A.id = B.id AND b.code BETWEEN '000' AND '123'
But, this still gives me the IDs that exist in Table B outside of the code range.
Use a left join, and filter the result to contain the codes in the range, and also the lines where there is no matching record in table B:
select
A.id
from
A
left join B on B.id = A.id
where
B.code between '000' and '123' or B.id is null
What about
SELECT id FROM A LEFT JOIN B ON A.id = B.id
WHERE b.code IS NULL OR b.code BETWEEN ' ' AND '123'
I have two tables, table A and table B, table A has and Id,a,b and c rows , Table B just has a,b and c and what i want (but i dont know how to do it) is to get a single row from Table B
(i would be something like comparinga,b,and c at the same time)
thanks!
SELECT A.id, B.a, B.b, B.c
FROM A
JOIN B
ON(A.a=B.a)
AND(A.b=B.b)
AND(A.c=B.c)
But I'd change your database structure and add foreign keyto table B referencing table A. It would really help you with this and later cases.
May I suggest changing your table structure.
TableA ( id primary key)
TableB(colA,colB,colC,fid foreign key refrencing TableA.id )
So now you dont have to store colA,colB,colC values in both TableA and TableB
Select B.*
From TableA A
Join TableB B
On A.id=B.fid
I have an empty table that I would like to fill with rows from a second table, based off a third table, Ill call them A,B,C respectively.
Table C has ID numbers that match ID numbers for rows in Table B. For every ID in table C, I want to add the corresponding row from table B into Table A.
This is what I have, and I am getting an error saying that I cannot use the last statement.
INSERT INTO TABLEA
SELECT * FROM TABLEB
WHERE ID FROM TABLEB = ID FROM TABLEC;
DSNT408I SQLCODE = -199, ERROR: ILLEGAL USE OF KEYWORD FROM. TOKEN ( . AT
MICROSECONDS MICROSECOND SECONDS SECOND MINUTES MINUTE WAS EXPECTED
DSNT418I SQLSTATE = 42601 SQLSTATE RETURN CODE
Any help would be appreciated.
INSERT INTO TableA
SELECT B.*
FROM TableB AS B
JOIN TableC AS C ON B.ID = C.ID
Or possibly that will give you too many duplicates (if there are multiple rows in C that match a given row in B), in which case you might need:
INSERT INTO TableA
SELECT B.*
FROM TableB AS B
WHERE B.ID IN (SELECT C.ID FROM TableC AS C)
Or:
INSERT INTO TableA
SELECT DISTINCT B.*
FROM TableB AS B
JOIN TableC AS C ON B.ID = C.ID
Both of those give you one row in A for each row in B that matches one or more rows in C.
How would I add a WHEN clause to this? Let's say Table C has another column called VALUE, and I want to add all the ID numbers that have a value of 'x' or greater. How would I do that, I tried adding JOIN TableC AS C ON B.ID = C.ID AND C.VALUE > 5 but I still got all the values from TABLE C.
Working with the first query (fixing the others being left as an 'exercise for the reader'), then what I think you should be doing is just:
INSERT INTO TableA
SELECT B.*
FROM TableB AS B
JOIN TableC AS C ON B.ID = C.ID
WHERE C.Value > 5
The optimizer should translate that to an equivalent expression:
INSERT INTO TableA
SELECT B.*
FROM TableB AS B
JOIN TableC AS C ON B.ID = C.ID AND C.Value > 5
I'm not clear from your comment whether you somehow added a second reference to TableC in the one query, or you modified your query as shown in this second example. If you were not using LEFT JOIN anywhere, then adding the AND C.Value > 5 term to the ON clause or as a WHERE clause should have yielded the correct data.
When debugging this sort of problem, it is worth noting that this INSERT statement has a perfectly good SELECT statement in it that you can run on its own to review what is going to be added to TableA. You might want to augment the select-list to include (at least) C.ID and C.Value just to make sure nothing is going haywire.
Trying to explain my Question:
Say, Table A contains ID,Number,Location.
Table B contains Option 1,Option 2.
I want to write a single query that would select ID, Number & Option 1 from the Table A and Table B.
(At present I am doing something like:
SELECT ID FROM [A]
SELECT Option 1 FROM [B]
)
You do this:
SELECT A.ID, A.Number, B.Option1
FROM TableA as A, TableB as B
WHERE A.id = B.id;
This Part sets an alias for the table so that you don't have type in the full table name all the time:
TableA as A
TableB as B
This part is the relationship between table A and B.
WHERE A.id = B.id;
Consider reading SQL table relationships http://net.tutsplus.com/tutorials/databases/sql-for-beginners-part-3-database-relationships/
I have a simple SQL question, I thought it would be quite straight forward but have got myself in a muddle. Any help would be appreciated
I have table A which contains a last updated
Table A has a one to many with Table B
Table B has a one to many with Table C
I want to show all rows of table C with the last updated time from table A. I have tried some joins but they dont seem to be quite working. Ideally I want somehting like
select a.lastUpdated c.* from TableA a, TableC c where
a.id in (select a_id from TableB where (select b_id from TableC where c_id = select
id from TableC where XXXX=YYYY))
so I can pass in an id for table C and then get one row returned with the last updated time present.
XXX=YYY would be my criteria for returning one row of table C.
Any help or pointers appreciated
Thanks
Something like
SELECT c.*
FROM TableA AS a
INNER JOIN TableB AS b
ON a.a_id = b.b_id
INNER JOIN TableC AS c
ON b.b_id = c.c_id
WHERE a.lastUpdated = c.lastUpdated;
Should work. This is a situation where a striaght INNER JOIN should suffice; unless of course I have missed something.
I hope this helps.
You should be able to do this by joining A and B together, aggregating the results at the c_id level, and then joining in C:
select tc.*, maxlastupdated
from tablec tc left outer join
(select tb.c_id, max(lastupdated) as maxlastupdated
from tablea ta join
tableb tb
on ta.b_id = tb.b_id
group by ta.id
) ta
on tc.c_id = ta.c_id
You need to drive your SQL query from Table C.
The query below displays the updated timestamp column from table A.
Since it is a one-to-many in the direction of tables A --> B --> C
You will inevitably end-up with a lot of rows in table C - all with the same timestamp.
SELECT c.*, a1.update_timestamp
FROM table_c c, table_b b, table_a a1
WHERE c.join_column = b.join_column
AND b.join_column = a1.join_column
AND a1.update_timestamp =
(SELECT max(a2.update_timestamp) FROM table_a a2
WHERE a2.<identifying columns> = a1.<identifying columns>
);