[RESOLVED] Can I have 2 On and Where Clauses in a Single Select of a Join?

swatisonee

Hi,

I'm finding my way thru JOINS and have this single statement to execute. It doesnt records because its syntactically wrong. I'm not able to figure out how I should change it and would appreciate some guidance. Thanks.


$sql = "SELECT `Enq`.* FROM `Enq` LEFT JOIN `Budget` 

ON `Enq`.Enquiryid=`Budget`.Enquiryid WHERE `Budget`.Enquiryid IS NULL 

AND ON  `Enq`.Visitid =`Budget`.Visitid WHERE `Budget`.Visitid IS NULL 

// syntactically wrong


AND ( (`Enq`.`Visitid`= '0' || `Enq`.`Visitid` IS NULL)

AND  `Enq`.Category!= 'D' AND `Enq`.Category!= 'A' ) 

and so on and so forth....

Basically, if the field Visitid has a value in Enq but does not appear in a record in Budget, it should get selected.
Also, all other records in Enq where Visitid is 0 or null should also get selected.
This is because, there are records in Budget with value in the Visitid field that correspond to a value in Enq and those should not be selected.

bpat1434

SELECT a.*
FROM `Eng` a
LEFT JOIN `Budget` b
  ON a.Enquiryid=b.Enquiryid
WHERE b.Enquiryid=NULL
  AND b.Visitid=NULL
  AND ((a.Visitid=0 OR a.Visitid=NULL)
    AND (a.Categoryid<>'D' AND a.Categoryid<>'A')
  )

That's the basis of it, but I have no idea if it would work with you... mainly because your question doesn't make much sense, and it's hard to get what you want....

swatisonee

Hi, thanks for replying.

I hope i can explain correctly :

a. I have 2 table that need to be joined.
b. I have 3 types of data to select from between these 2 tables.
all records from Enq which do not find a match in Budget
all records from Enq where the field visitid has null value but field enquiryid

has a value which can be matched in Budget
* all records from Enq where the field visitid has a value which cannot be found
in Budget.

Records have to be scanned to check that both the enquiryid and visitid fields of Budget return null values. My problem is the second and third have records which can be subsets of the first.

The field visitid comes from a third table called Visit.

I tried this code but it doesnt return any records although a physical verifcation indicates that 5 should have been selected.

$sql = "SELECT `Enq`.* FROM `Enq` LEFT JOIN `Budget` 

ON `Enq`.Enquiryid=`Budget`.Enquiryid WHERE `Budget`.Enquiryid IS NULL 

AND `Enq`.Visitid=`Budget`.Visitid  AND `Budget`.Visitid IS NULL 

AND ( (`Enq`.`Visitid`= '0' || `Enq`.`Visitid` IS NULL)  

AND  `Enq`.Category!= 'D' AND `Enq`.Category!= 'A' )

Any suggestions pl? Thanks.

bpat1434

a.) Taken care of with the join

You want to match the entire table against the entire table? That's one huge query that matches something like what I posted above.....

swatisonee

Hi,

I have worked on this a bit more but i have the foll. error :

Not unique table/alias: 'Budget'

$sql = "SELECT `Enq`.* FROM `Enq` 
LEFT JOIN `Budget` ON `Enq`.Enquiryid=`Budget`.Enquiryid  

LEFT JOIN `Budget` ON `Enq`.Visitid=`Budget`.Visitid
WHERE `Budget`.Enquiryid IS NULL 
AND  `Budget`.Visitid IS NULL 
AND  `Enquiries03-04`.Category!= 'D' AND `Enquiries03-04`.Category!= 'A'

Is there a way I could combine 2 select in one statement so that the foll . 2 sqls both get queried ?

$sql = "SELECT `Enq`.* FROM `Enq` 
LEFT JOIN `Budget` ON `Enq`.Enquiryid=`Budget`.Enquiryid  

WHERE `Budget`.Enquiryid IS NULL 
AND  `Enquiries03-04`.Category!= 'D' AND `Enquiries03-04`.Category!= 'A'

and

$sql = "SELECT `Enq`.* FROM `Enq` 
LEFT JOIN `Budget` ON `Enq`.Visitid=`Budget`.Visitid
WHERE `Budget`.Visitid IS NULL 
AND  `Enquiries03-04`.Category!= 'D' AND `Enquiries03-04`.Category!= 'A'

All advise welcome . Thnaks

barand

Use a UNION to get the combined results

            SELECT `Enq`.* FROM `Enq` 
            LEFT JOIN `Budget` ON `Enq`.Enquiryid=`Budget`.Enquiryid  

            WHERE `Budget`.Enquiryid IS NULL 
            AND  `Enquiries03-04`.Category!= 'D' AND `Enquiries03-04`.Category!= 'A'
            UNION
            SELECT `Enq`.* FROM `Enq` 
            LEFT JOIN `Budget` ON `Enq`.Visitid=`Budget`.Visitid
            WHERE `Budget`.Visitid IS NULL 
            AND  `Enquiries03-04`.Category!= 'D' AND `Enquiries03-04`.Category!= 'A'

swatisonee

Yes !! It worked . Thank you !