I have two table say TableA and TableB with below structure
TableA
cust_name
cust_id
cust_age
TableB
id
cust_id
balance
I need to join these two tables all retrieve the below columns
tableA.cust_name,tableA.cust_age,tableB.balance
but if I use the below query
select a.cust_name,a.cust_age,sum(b.balance) from tableA a,tableB b
where a.cust_id=b.cust_id and b.id = (select max(id) from tableB where cust_id=b.cust_id)
I only get those rows which are present in both the tables, but i need all the rows where there is a customer in tableA and not in tableB the b.balance should come either null or 0.
I would say Left join
SELECT a.cust_name, a.cust_age, sum(nvl(b.balance,0))
FROM tableA a
LEFT JOIN tableB b
ON a.cust_id=b.cust_id
GROUP BY a.cust_name, a.cust_age
Also use NVL as you may get some nulls in b.balance.
Alternatively if you are on an old Oracle version you have to use a different join:
SELECT a.cust_name, a.cust_age, sum(nvl(b.balance,0))
FROM tableA a, tableB b
where a.cust_id=b.cust_id (+)
GROUP BY a.cust_name, a.cust_age
Related
I like to keep all records in tableA that are right after my targeted date,
Main table A
Table B
SELECT *
FROM tableA a
LEFT JOIN tableB b on b.customerID = a.customerID and b.target_date = a.sell_date
WHERE a.sell_date > b.target_date
Unfortunately my code above doesn't work since SQL can't compare NULL with date.
My expected output is
The inequality between target_date and sell_date could go in the join condition of the FROM clause. This way the WHERE clause could be eliminated.
SELECT *
FROM tableA a
LEFT JOIN tableB b on b.customerID=a.customerID
and b.target_date <= a.sell_date;
I have a following tables:
TableA
id
name
TableB
id
tableA_id
TableC
id
tableA_id
So tables B and C have tableA_id fk.
I need a query which will return all id-s from TableA that have reference in either TableB or TableC.
If I do standard join, it will return only values that have reference in both tables B and C.
I could do this using two queries, one joins B, other joins C and use UNION to merge results, but I dont want to write same query twice.
Is there a way to achieve this 'OR' JOIN??
Try with this
SELECT DISTINCT TABLEA.ID_A, TABLEA.NAME
FROM TABLEA,TABLEB,TABLEC
WHERE TABLEA.ID_A = TABLEB.ID_A AND TABLEA.ID_A = TABLEC.ID_A
Using DISTINCT TAG you eliminate duplicates.
Something like this?
SELECT
*
FROM
TableA,
TableB,
TableC
WHERE
TableA.id = TableB.tableA_id
OR TableA.id = TableC.tableA_id
You can use left outer joins and checks for the ids:
SELECT a.id FROM A a
LEFT JOIN B b ON a.id = b.tableA_id LEFT JOIN C c ON a.id = c.tableA_id
WHERE b.id IS NOT NULL OR c.id IS NOT NULL
For some reason I have a hard time grasping joins and this one should be very simple with the knowledge that I have in SQL.
Anyway, I have 2 tables. We will call them TableA and TableB. One of the columns in TableA is "ID". TableB only consists of the column "ID". I want to return all rows in TableA whose ID is present in TableB.
I know this should be very simple to figure out, but my brain doesn't want to work today.
You can do this using an EXISTS:
Select A.*
From TableA A
Where Exists
(
Select *
From TableB B
Where A.Id = B.Id
)
You can also use a JOIN if you wish, but depending on your data, you may want to couple that with a SELECT DISTINCT:
Select Distinct A.*
From TableA A
Join TableB B On A.Id = B.Id
One thing to keep in mind is that the ID of TableA is not necessarily related to the ID of TableB.
this should work
SELECT B.ID
FROM TableA A
JOIN TableB B
ON (A.ID=B.ID)
WHERE A.ID=B.ID
You can also use IN operator like this:
Select *
From TableA
Where ID in
(
Select distinct ID
From TableB
)
I'm trying to join two tables like this:
Table A
ID Value1
1 A
2 B
3 C
Table B
ID Value2
1 A
3 B
4 C
Result should be:
ID Value1 Value2
1 A A
2 B null
3 C B
4 null C
I.e. join Table A to Table B on ID. If ID doesn't exist in Table A, add the ID from Table B.
The closest I've come is:
SELECT
a.ID, a.Value1, b.Value2
FROM
TableA a
OUTER JOIN
TableB b ON a.ID = b.ID
That gives me the new rows from TableB, but the ID is null.
How can I accomplish this?
You are very close, you just need a little push in the right direction:
SELECT COALESCE(a.ID, B.ID) As ID, a.Value1, b.Value2
FROM TableA a
FULL OUTER JOIN TableB b ON a.ID=b.ID
The COALESCE function returns the first parameter it gets that is not null. since this is a full outer join, a.id will be null on one row and b.id would be null on a different row.
Try this:
SELECT *
FROM TableA A
FULL OUTER JOIN TableB B
ON A.ID = B.ID;
Just a note: you should not name your tables in SQL with spaces in them.
Remember the basic for joining different tables
SELECT column_name(s)
FROM table1
FULL OUTER JOIN table2
ON table1.column_name=table2.column_name;
For your case:
SELECT a.value1, b.value2
FROM TableA a
FULL OUTER JOIN TableB b ON a.ID=b.ID
remember full outer join
The FULL OUTER JOIN keyword returns all rows from the table (tableA) and from the table (tableB) and the FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins.
I want to use parameters stored in tableA to filter tableB.
Here is my tableA with parameters:
I want to filter tableB with more or less such a query:
WITH A AS
(SELECT
[FilterType]
,[MaxID]
FROM TableA
WHERE [FilterType]=1
)
SELECT * FROM TableB B
WHERE B.ID>A.MaxID
I want to get all the records from TableB where B.ID is larger than MaxID chosen from TableA for a FilterType 1. How to do it? Speaking more generally, how to get a parameter from table and use this parameter for query?
Not a lot of detail here but something like this?
select b.Columns
from TableB b
join TableA a on a.MaxID <= b.ID
where a.FilterType = 1
SELECT B.*
FROM TableB AS B
JOIN TableA AS A ON B.ID > A.MaxID
WHERE A.FilterType = 1
WITH A AS
(SELECT
[FilterType]
,[MaxID]
FROM TableA
WHERE [FilterType]=1
)
SELECT B.* FROM TableB B,A
WHERE B.ID>A.MaxID