Progressive databse searching

[xcandiottix]

I need to perform a search of my DB using 6 fields. I want to progress thru the searches as so:

 

Row: A B C D E F

 

Select A, if A then select B, if B then select C if C then select D, if D select E, if E then select F

 

I then want to extract the data from each field.

 

if A then $a = A, if B then $b = B, etc etc.

 

I don't want to have a whole bunch of different select statements or if conditions if I don't need to. Also, the DB is rather large so i think evaluating:

 

$query = "SELECT * FROM table"

 

Might be overkill. Is there anyway to do something like:

 

$queryA = SELECT * FROM table WHERE A = subject1
if($queryA){$queryB = SELECT * FROM $queryA WHERE B = subject2}
if($queryB){$queryC = SELECT * FROM $queryB WHERE C = subject3}
etc etc etc

 

So basically I just progressively filter down one original mysql query to get what I need.

[btherl]

You can select them all and then order them so that the result you want appears first .. the exact sql depends on your database structure.  But it won't be pretty.

 

I suggest you do it in php unless you have a good reason not to.

[Psycho]

Maybe I am not understanding the request - kind of confusing. But, it seems he is just wanting a query with multiple where clauses:

SELECT *
FROM table
WHERE A = subject1
  AND B = subject2
  AND C = subject3
  AND D = subject4
  AND E = subject5
  AND F = subject6

[btherl]

Hmm, on re-reading the original post, this might be a job for left joins .. eg

 

SELECT A,B,C,D,E,F FROM tab1
LEFT JOIN tab2 ON (tab2.A = tab1.A)
LEFT JOIN tab3 ON (tab3.B = tab2.B)
...
WHERE A = subject1

 

That implements "If there's a result from tab1, then fetch matching data from tab2.  If there's a result from tab2, fetch matching data from tab3"