Logical Databases PNP

Question

I am working with logical databases for the first time.
Could someone please explain the following concepts :
1) why do we need to write :
     Tables : pernr
pernr is a structure... but the syntax of GET event is : GET <table> ...
so is pernr a structure or a table?
also if data gets flled from PAnnn into the internal tables Pnnnn why do we actually need the table pernr?
could some1 plz explain the concep of the pernr structure/table and the GET event.
results will be awarded.

Answer 1

Hi soumali ganguly ,
  1> Yes , a structure of "pernr" will be created with the help of TABLES statement .
  2> We write "TABLES" statement in the report program , so that the components of the
  "pernr" can be accessed .
  3> Keep in mind that Logical DataBase(LDB) is another program attached to a report program .
  4> You write GET statement in the report program . There is corresponding PUT
       statement in the LDB program .
  5> Now understand the flow of execution :
            a> On the encounter of "GET pernr" statement in the report program ,
            the control will move to the form "PUT_PERNR" . This form is in the LDB .
             b> So , now control is in LDB . On the encounter of "PUT pernr" statement in the  
           "PUT_PERNR" form in LDB , the system will now execute the statements
            written in the GET block .
            c> Generally in the GET block , we access the components of "pernr" .
      d> After the GET block has finished execution , the control will now again move to
           statement after "PUT pernr" statement , in the LDB .
            e> If the "PUT pernr" statement in LDB form "PUT_PERNR" is inside a loop ,
          as generally is the case , this "GET-PUT" cycle is repeated several times .
     In short , keep in mind PUT puts the data (one line at a time) in the "pernr"and
     GET allows to access the data in "permr" , placed by PUT .
      Please do let me know in case of any discrepancies .
Regards ,
Dhera Kamlesh H. R.