Joined: 22 Feb 2007 Posts: 8 Topics: 3 Location: Roswell, GA
Posted: Fri Feb 23, 2007 7:40 am Post subject: Join 2 tables
Problem: I have to do a select on two tables - one that has to join back to itself. I can't code it right.
Table A looks like this: aa,ab,ac,ad...ay,az
Table B looks like this: aa, bb, bc, bd ...
The result table should look like this:
Code:
aa,
ab,
bb,
bc,
ab(from A row where aa = ay)
ab(from A row where aa = az),
ae,
af,
ag.
I tried a number of selects but can't even get past edit.
First I used a case statement:
Code:
Select A.ab,A.ac,B.bb,B.bc,
Case
when ay = ' ' then ' '
else select ab from c.A where c.aa = a.xy.
End case
, Case
when az = ' ' then ' '
else select ab from c.A where c.aa = a.xz.
End case
, ae , af, ag
from a.A b.B
Then I tried Union All with a subselect on the selected set.
Code:
Select A.ab,A.ac,B.bb,B.bc,ay,az,ae,af from a.A B.b Union all
case
if ay null and az null
Select A.ab,A.ac,B.bb,B.bc,' ' , ' ',ae,af from A A, B B
end case
case
if ay null and az not null
Select A.ab,A.ac,B.bb,B.bc,' ' ,
select c.ab from ' ',ae,af from A A, B B
end case
Joined: 26 Nov 2002 Posts: 12376 Topics: 75 Location: San Jose
Posted: Fri Feb 23, 2007 9:58 am Post subject:
Table A has the following columns and denoted X
Code:
COL1
COL2
COL3
COL4
Table B has the following columns and denoted Y
Code:
COL1
COL2
COL3
COL4
The following sql will give you the desired results.
Code:
SELECT X.COL2
,CASE WHEN X.COL3 IS NULL AND X.COL4 IS NULL
THEN CHAR('-')
WHEN SUBSTR(X.COL3,1,2) = 'AA' AND X.COL4 IS NULL
THEN CHAR('-')
WHEN X.COL3 IS NULL AND SUBSTR(X.COL4,1,2) = 'AA'
THEN CHAR('AB') || SUBSTR(X.COL4,3,1)
ELSE X.COL3 END
,CASE WHEN X.COL4 IS NULL AND X.COL3 IS NULL
THEN CHAR('-')
WHEN SUBSTR(X.COL4,1,2) = 'AA' AND X.COL3 IS NULL
THEN CHAR('-')
WHEN X.COL4 IS NULL AND SUBSTR(X.COL3,1,2) = 'AA'
THEN CHAR('AB') || SUBSTR(X.COL3,3,1)
ELSE X.COL4 END
,Y.COL2
,Y.COL3
FROM Tablea X
,Tableb Y
WHERE X.COL1 = Y.COL1
;
Joined: 22 Feb 2007 Posts: 8 Topics: 3 Location: Roswell, GA
Posted: Fri Feb 23, 2007 12:20 pm Post subject:
THX, THIS IS WHAT I'M CODING... WILL IT WORK?
Code:
SELECT DISTINCT
A.ID, A.NBR, B.NM, B.LOB, A.OPEN, A.CLS
,CASE WHEN A.TX IS NULL THEN CHAR('-')
WHEN A.TX = C.ID THEN C.NBR
END
,CASE WHEN A.FR IS NULL THEN CHAR('-')
WHEN A.FR = C.ID THEN C.NBR
END
, A.TYP_CD , A.SZ_CD
FROM STR A , HIER B , STR C
WHERE A.ID = B.ID
Joined: 22 Feb 2007 Posts: 8 Topics: 3 Location: Roswell, GA
Posted: Sat Feb 24, 2007 2:17 pm Post subject: almost works
There's a third table involved and I wound up with a 5,000,000 row result so I added distinct and it's now down to almost the right result but I am getting duplicate rows, only, when the ay,az are not null and then I get botht the row with null and with the right aa value?
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