Fetching records from multiple tables logically with SQLServer - sql

Question

I am having a problem with fetching the records.
Finding it too difficult to get tis but though I am trying.
Please help me regarding this::
Actually My requirement is to get that records from table1 whose sender and reciever userid =5 and to that corresponding records if the pkId of the selected result exists in
table2 as fkid and have to check userId again in table2 with Isdeleted=false
I want to get records from table1 only where sender=5 or receiver=5
and then I need to check the pkId of table1 if it exists in
table2 as fkId then idDeleted should be false but
while checking from table2, I am having a condition to search only where
table2.userid =5
I have tried this but not working
select distinct pkId , Message, data from table1
left outer join table2 on
table2.fkId =table1.pkMessageId
where ((table1.sender ='5' or table1.receiver='5' )
or table2.userid='5') and table2.isDeleted=0
table1
pkId sender receiver Message data date
1 2 5 M1 D1 blah_Blah
2 2 5 M2 D2 blah_Blah
3 5 7 M3 D3 blah_Blah
4 5 2 M4 D4 blah_Blah
5 5 2 M5 D4 blah_Blah
table2
Id fkId userid isDeleted
1 1 5 true
2 1 5 false
3 2 5 false
4 2 2 false
5 3 2 false
6 4 2 true
7 1 2 true
8 2 2 false

Answer 1

Try this:
Select distinct pkId , Message, data from table1
Where (sender = 5 Or receiver = 5) and pkId in
(
Select fkid From table
Where isDeleted=0
)

Answer 2

You should be able to avoid the distinct with an EXISTS statement:
select pkId, Message, data
from table1
where exists ( select 1
from table2
where table2.fkId = table1.pkMessageId
and table2.isDeleted=0
and table2.userid='5' )
and (sender ='5' or receiver='5' )
This is assuming a few things though:
table2.fkId = table1.pkMessageId is the right way of joining the two tables (pkMessageId is lacking in your example data)
You do not want table1.sender ='5' or table1.receiver='5' or table2.userid='5'
If you want OR, OR, OR, this could be what you are looking for:
select pkId, Message, data
from table1
where exists ( select 1
from table2
where table2.fkId = table1.pkMessageId
and table2.isDeleted = 0
and table2.userid='5' )
or sender ='5'
or receiver='5'

Answer 3

I think your issue is you are using the same table for sender and receiver you need to join to the same table twice...
SELECT * FROM Table1
INNER JOIN Table2 Sender
ON Table1.Sender = Sender.userid
INNER JOIN Table2 Receiver
ON Table1.Receiver = Receiver.userid
WHERE
Receiver.isDeleted = 0
AND
Sender.isDeleted = 0
AND
(
Receiver.userid = 5
OR
Sender.userid = 5
)
from your description what you are saying is
SELECT
T1.*
FROM
Table1 T1
INNER JOIN
Table2 T2
ON
T1.pkId = T2.fkId
WHERE
(T1.Sender = 5 OR T1.Receiver = 5)
AND
T2.isDeleted = 0
AND
T2.userid = 5

Answer 4

I will go step by step through your new version of your requirements:
Actually My requirement is to get that records from table1 whose sender and reciever userid =5 and to that corresponding records if the pkId of the selected result exists in table2 as fkid and have to check userId again in table2 with Isdeleted=false
I'll take this step by step.
records from table1 whose sender and reciever userid =5
That is easy, in your example data, there are no such records.
Now, I will assume you mean
records from table1 whose sender OR reciever userid =5
So that leads to a first part of our query:
SELECT *
FROM Table1 t1
WHERE t1.sender = 5
OR t1.receiver = 5
Then, we go further:
and to that corresponding records if the pkId of the selected result exists in table2 as fkid
So, we LEFT JOIN table 2 on matching keys:
SELECT *
FROM Table1 t1
LEFT JOIN Table2 t2 ON t1.pkID = t2.fkId
WHERE t1.sender = 5
OR t1.receiver = 5
Almost there:
and have to check userId again in table2 with Isdeleted=false
I am assuming you want to only add the extra data from table2 if this condition is met, but is the condition is not met, you still want the data from table1. To acheive this, I will put this condition in the JOIN condition, rather than in th eWHERE clause. In the where clause, if the condition is not met, the whole record will be removed, not just the data from table2.
SELECT *
FROM Table1 t1
LEFT JOIN Table2 t2 ON t1.pkID = t2.fkId
AND t2.IsDeleted = 0
WHERE t1.sender = 5
OR t1.receiver = 5
Now, this looks a lot like what you already had created, but I would not know why it would not give you the desired result. So if this does not give you the desired or expected result, please tell us what is going wrong :)

Answer 5

--Try Like This..
SELECT * FROM Table1
Where ( Sender = 5
OR Reciever = 5 )
AND PKID in ( Select FKID From Table2 Where IsDeleted = 0)
-- It would be easy if u can provide the table structures also...