SQL Query -- Please Help

Question

Table1
QTE_ID     SEQ_NO
1435177     2
1435177     5
1435177     7
1435177     8
1435177     12
1435177     14
Table2
QTE_ID     SEQ_NO     CMMT_CURR_AMT
1435177     1     98500
1435177     2     98500
1435177     3     0
1435177     4     98500
1435177     5     98500
1435177     7     98500
1435177     8     98500
1435177     11     59300
1435177     12     59300
1435177     14     59300
The result should be
QTE_ID     SEQ_NO     CMMT_CURR_AMT
1435177     2     0 (where 0 = cmmt_curr_amt of seq 2 - cmmt_curr_amt of seq 1 from table 2)
1435177     5     0 (where 0 = cmmt_curr_amt of seq 5 - cmmt_curr_amt of seq 4 from table 2)
1435177     7     0 (where 0 = cmmt_curr_amt of seq 7 - cmmt_curr_amt of seq 5 from table 2)
1435177     8     0 (where 0 = cmmt_curr_amt of seq 8 - cmmt_curr_amt of seq 7 from table 2)
1435177     12     0 (where 0 = cmmt_curr_amt of seq 12 - cmmt_curr_amt of seq 11 from table 2)
1435177     14     0 (where 0 = cmmt_curr_amt of seq 14 - cmmt_curr_amt of seq 12 from table 2)
I have to get the difference of cmmt_curr_amt from the table2 from seq 14 to seq 12 for seq14 in table 1.
Please help me in writing the query.
Thanks in advance.
Srinivas

Answer 1

WITH table1 AS
(SELECT 1435177 qte_id, 2 seq_no
FROM dual
UNION ALL
SELECT 1435177 qte_id, 5 seq_no
FROM dual
UNION ALL
SELECT 1435177 qte_id, 7 seq_no
FROM dual
UNION ALL
SELECT 1435177 qte_id, 8 seq_no
FROM dual
UNION ALL
SELECT 1435177 qte_id, 12 seq_no
FROM dual
UNION ALL
SELECT 1435177 qte_id, 14 seq_no
FROM dual
table2 AS
SELECT 1435177 qte_id, 1 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 2 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 3 seq_no, 0 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 4 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 5 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 7 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 8 seq_no, 98500 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 11 seq_no, 59300 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 12 seq_no, 59300 cmmt_curr_amt
FROM dual
UNION ALL
SELECT 1435177 qte_id, 14 seq_no, 59300 cmmt_curr_amt
FROM dual
SELECT qte_id, t2_seq_no, cmmt_curr_amt - cmmt_curr_lag diff
FROM
(SELECT t2.qte_id, t2.seq_no t2_seq_no, t1.seq_no t1_seq_no, cmmt_curr_amt, LAG(cmmt_curr_amt,1,0) OVER (PARTITION BY t2.qte_id ORDER BY t2.seq_no) cmmt_curr_lag
FROM table1 t1, table2 t2
WHERE t2.qte_id = t1.qte_id (+)
AND t2.seq_no = t1.seq_no(+)
ORDER BY 1,2
WHERE t1_seq_no IS NOT NULL
ORDER BY 1,2
QTE_ID T2_SEQ_NO DIFF
1435177 2 0
1435177 5 0
1435177 7 0
1435177 8 0
1435177 12 0
1435177 14 0