Help two sql queries toload target table

Question

create table table1
    (code varchar2(10)
     ,mod_time date);
     insert into table1 values('2533',to_date('31-JUL-2012', 'DD-MON-YY'));
     insert into table1 values('2534',to_date('31-JUL-2012', 'DD-MON-YY'));
      insert into table1 values('2535',to_date('01-SEP-2012', 'DD-MON-YY'));
      create table table2
    (code varchar2(10)
     ,ID   NUMBER
     ,TYPE VARCHAR2(3)
     ,mod_time date);
     insert into table2 values('2533',1,'AB',to_date('01-SEP-2012', 'DD-MON-YY'));
     insert into table2 values('2534',1,'CD',to_date('01-SEP-2012', 'DD-MON-YY'));
     create table table3
     (ID   NUMBER
      ,mod_time date);
      insert into table3 values(1,to_date('01-SEP-2012', 'DD-MON-YY'));
      insert into table3 values(2,to_date('01-SEP-2012', 'DD-MON-YY'));
      create table target
      (code varchar2(10)
      ,ID   NUMBER
      ,TYPE VARCHAR2(3)
      ,table1_modtime date
      ,table2_modtime date
      ,table3_modtime date
      ,valid_till  date
      ,valid_from  date
      drop table target
      combine all the three tables where table1.mod_time<=31-jul-2012, table2.mod_time<=31-jul-2012,table3.mod_time<=31-jul-2012
      initial load to target load should be get the information from all the tables modtime<=31-jul-2012
      Need to have select query to get the below 1st load expected output
      valid_till defaults to to_date('31-DEC-2030', 'DD-MON-YY')
      valid_from defaults to to_date('01-01-1995', 'DD-MON-YY')
     1st load expected output
      code    id     type  table1_modtime   table2_modtime      table3.modtime  valid_from valid_till  
      2533                 31-JUL-2012                                                            01-01-1995  31-DEC-2030 
      2534                 31-JUL-2012                                                             01-01-1995   31-DEC-2030 
      -------------------------------------------------------------------------------------------------------for the second load. first get the query to get the values from all the tables
mod_time>31-jul-2012 .
if the code exists then update the existing record with valid_till to 02-jan-2013 i.e yesterday
and insert new record with the new values and valid from date to 03-jan-2013 i.e today
    --------------------2nd load expected output 
      code    id     type  table1_modtime   table2_modtime      table3.modtime      valid_from     valid_till
      2533                 31-JUL-2012                                                               01-01-1995       02-jan-2013 --updating old record valid-till to yesterday
      2534                 31-JUL-2012                                                               01-01-1995       02-jan-2013  --updating old record valid-till to yesterday
      2533      1     AB   31-JUL-2012        01-SEP-2012        01-SEP-2012         03-jan-2013  31-DEC-2030----updating old record valid-from to today
      2534      1     CD   31-JUL-2012        01-SEP-2012       01-SEP-2012          03-jan-2013  31-DEC-2030--updating old record valid-from to today
      2535                  01-SEP-2012                                                              01-01-1995  31-DEC-2030 --no record exist so insert new record in target table
  Edited by: choti on Jan 3, 2013 5:01 PM

Answer 1

Hi ,
Just check the data you have inserted into the tables because, trying to join the table and putting the date constraint its returning no values
select T1.CODE as code ,t3.id as id ,t2.type as type  ,T1.MOD_TIME as table1_modtime ,T2.MOD_TIME as table2_modtime ,T3.MOD_TIME as table3_modtime from table1 t1, table2 t2,table3 t3 where T1.CODE = t2.code and t2.id = t3.id
and t1.mod_time<=to_date('31-jul-2012', 'DD-MON-YY')
and t2.mod_time<=to_date('31-jul-2012', 'DD-MON-YY')
and t3.mod_time<=to_date('31-jul-2012', 'DD-MON-YY')And this because for the code 2533 and 2534 in the table1 the id entry in the table2 is 1 . but the date entry in the table3 for the Id 1 is 01-SEP-2012 which falls outside the date. Kindly confirm on this data entry in table2.