after applying join condition on two tables i want records which is maximum among records of left table
my query
SELECT a1.*,
t.*,
( a1.trnratefrom - t.trnratefrom )AS minrate,
( a1.trnrateto - t.trnrateto ) AS maxrate
FROM (SELECT a.srno,
trndate,
b.trnsrno,
Upper(Rtrim(Ltrim(b.trnstate))) AS trnstate,
Upper(Rtrim(Ltrim(b.trnarea))) AS trnarea,
Upper(Rtrim(Ltrim(b.trnquality))) AS trnquality,
Upper(Rtrim(Ltrim(b.trnlength))) AS trnlength,
Upper(Rtrim(Ltrim(b.trnunit))) AS trnunit,
b.trnratefrom,
b.trnrateto,
a.remark,
entdate
FROM mstprodrates a
INNER JOIN trnprodrates b
ON a.srno = b.srno)a1
INNER JOIN (SELECT c.srno,
trndate,
d.trnsrno,
Upper(Rtrim(Ltrim(d.trnstate))) AS trnstate,
Upper(Rtrim(Ltrim(d.trnarea))) AS trnarea,
Upper(Rtrim(Ltrim(d.trnquality))) AS trnquality,
Upper(Rtrim(Ltrim(d.trnlength))) AS trnlength,
Upper(Rtrim(Ltrim(d.trnunit))) AS trnunit,
d.trnratefrom,
d.trnrateto,
c.remark,
entdate
FROM mstprodrates c
INNER JOIN trnprodrates d
ON c.srno = d.srno) AS t
ON a1.trnstate = t.trnstate
AND a1.trnquality = t.trnquality
AND a1.trnunit = t.trnunit
AND a1.trnlength = t.trnlength
AND a1.trnarea = t.trnarea
AND a1.remark = t.remark
WHERE t.srno = (SELECT MAX(srno)
FROM a1
WHERE srno < a1.srno)
