MINUS IN SQL PLUS

Question

Hi I have this query and it returns 4 records one of those is a duplicate
SQL> col adjustment_reason format a30
SQL> SELECT account_no ,descr as adjustment_reason,
2 gl_id,amount as adjustmentamount
3 FROM src_misc_adj_rpt;
ACCOUNT_NO ADJUSTMENT_REASON GL_ID ADJUSTMENTAMOUNT
1-36795186 Acct Transfer Adjust-System 135 -37.61
1-36795186 Acct Transfer Adjust-System 135 59.24
1-36795186 Acct Transfer Adjust-System 135 -36.78
1-36795186 Acct Transfer Adjust-System 135 -36.78
and another query
SQL> SELECT account_no ,descr as adjustment_reason,
2 gl_id,amount as adjustmentamount
3 FROM tgt_misc_adj_rpt;
no rows selected
I get no results
I am doing a minus on these
SQL> SELECT account_no ,descr as adjustment_reason,
2 gl_id,amount as adjustmentamount
3 FROM src_misc_adj_rpt
4 MINUS
5 SELECT account_no ,descr as adjustment_reason,
6 gl_id, amount as adjustmentamount
7 FROM tgt_misc_adj_rpt;
ACCOUNT_NO ADJUSTMENT_REASON GL_ID ADJUSTMENTAMOUNT
1-36795186 Acct Transfer Adjust-System 135 -37.61
1-36795186 Acct Transfer Adjust-System 135 -36.78
1-36795186 Acct Transfer Adjust-System 135 59.24
I get only 3 records . I want to get all the 4 records even the duplicate record. Is there any other way to do that

Answer 1

Shahid Ali Tcs wrote:
Still question is why minus is removing duplicate rows?MINUS, INTERSECT, UNION etc. are "set operations".
In mathematics, generally speaking, sets contain a set of values, not the number of occurences of them.
Hence, when you use set operations on your data, it looks at the values in the set, and not the number of occurences, so what is returned is the resultant values of the operation. i.e. it turns from being a table of rows to a set of values.
e.g. if you get the union of data in the sets...
SQL> ed
Wrote file afiedt.buf
  1  with t as (select 1 as num from dual union all
  2             select 2 from dual union all
  3             select 3 from dual union all
  4             select 3 from dual union all
  5             select 4 from dual)
  6      ,t2 as (select 2 as num from dual union all
  7              select 2 from dual)
  8  --
  9  select * from t
10  union
11* select * from t2
SQL> /
       NUM
         1
         2
         3
         4... you just get 1 occurence of each value
Likewise if you request the intersection of the sets...
SQL> ed
Wrote file afiedt.buf
  1  with t as (select 1 as num from dual union all
  2             select 2 from dual union all
  3             select 3 from dual union all
  4             select 3 from dual union all
  5             select 4 from dual)
  6      ,t2 as (select 2 as num from dual union all
  7              select 2 from dual)
  8  --
  9  select * from t
10  intersect
11* select * from t2
SQL> /
       NUM
         2... you just get the value that intersects, not all occurences of it
And, of course as you've found out...
SQL> ed
Wrote file afiedt.buf
  1  with t as (select 1 as num from dual union all
  2             select 2 from dual union all
  3             select 3 from dual union all
  4             select 3 from dual union all
  5             select 4 from dual)
  6      ,t2 as (select 2 as num from dual union all
  7              select 2 from dual)
  8  --
  9  select * from t
10  minus
11* select * from t2
SQL> /
       NUM
         1
         3
         4... minus only deals with the values, not the occurences
The one exception to the rule is oracles implementation of UNION ALL...
SQL> ed
Wrote file afiedt.buf
  1  with t as (select 1 as num from dual union all
  2             select 2 from dual union all
  3             select 3 from dual union all
  4             select 3 from dual union all
  5             select 4 from dual)
  6      ,t2 as (select 2 as num from dual union all
  7              select 2 from dual)
  8  --
  9  select * from t
10  union all
11* select * from t2
SQL> /
       NUM
         1
         2
         3
         3
         4
         2
         2
7 rows selected.... where the ALL keyword specifically indicates that we want to deal with the occurences when unioning the sets together.
It's all in the documentation...
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/queries004.htm#i2054381