Procedure Guidance Required

Question

Hi all,
Can I write a procedure in oracle which check the data in external table or flat file and insert the required data into internal oracle table.
Please Guide me in this regard it is urgent.

Answer 1

SQL> select * from myinternaltable;
        ID NAME
         1 Fred
         2 Bob
         3 Jim
SQL> select * from myexternaltable;
        ID NAME
         1 Fred
         3 Jimmy
         4 Tim
SQL> create table ins_upd as select * from myinternaltable where 1=0;
Table created.
SQL> create table del_upd as select * from myinternaltable where 1=0;
Table created.
SQL> create table upd as select id from myinternaltable where 1=0;
Table created.
SQL> create table ins as select id from myinternaltable where 1=0;
Table created.
SQL> create table del as select id from myinternaltable where 1=0;
Table created.
SQL> ed
Wrote file afiedt.buf
  1  create or replace procedure myproc as
  2  begin
  3    execute immediate 'truncate table ins_upd';
  4    execute immediate 'truncate table del_upd';
  5    execute immediate 'truncate table upd';
  6    execute immediate 'truncate table ins';
  7    execute immediate 'truncate table del';
  8    insert into ins_upd
  9    select * from myexternaltable
10    minus
11    select * from myinternaltable;
12    insert into del_upd
13    select * from myinternaltable
14    minus
15    select * from myexternaltable;
16    insert into upd
17    select id from ins_upd
18    intersect
19    select id from del_upd;
20    insert into ins
21    select id from ins_upd
22    minus
23    select id from upd;
24    insert into del
25    select id from del_upd
26    minus
27    select id from upd;
28    insert into myinternaltable
29    select * from myexternaltable
30    where id in (select id from ins);
31    delete from myinternaltable
32    where id in (select id from del);
33    update myinternaltable
34    set name = (select name
35                from myexternaltable
36                where id = myinternaltable.id)
37    where id in (select id from upd);
38* end;
SQL> /
Procedure created.
SQL> exec myproc
PL/SQL procedure successfully completed.
SQL> select * from myinternaltable;
        ID NAME
         1 Fred
         3 Jimmy
         4 Tim
SQL>Remember, you can use the MERGE statement to achieve similar results, however this way allows you to carry out any other processing that you may require for records in certain states before you insert,update,delete from your internal table.