DATA AREA IN AS/400

 DATA AREA

 

Data Area is a data storing file,one data area can store only one record of data, the size of Data area is 2048 bytes.The stored data is retrieved when ever is needed and where ever is needed.Data Area won't have source but by creation object will be created in the library.To see whether the data area is created or not use "WRKOBJPDM".
Data Areas are of two categories those are
             1.System defined data area and
             2.User defined data area.
System defined data area is temporary storage area that means we can store data in that and if the data is retrieved  that retrieved data will expire.These data areas can not be created and deleted by user but the user can add data to these data areas,retrieve and display.
System defined data areas are of 3 types
1.Local data area (LDA): These are created automatically by each and every job(batch or interactive),
2.Group data area (GDA):These are created automatically by a group of jobs.
3.PIP(program initialize parameter) data area(PDA):These are created for using at the time of starting a job from it's abnormal termination.
User defined data area is permanent storage area that means we can store data permanently it can be retrieved as many times we needed.These data area can be created,displayed,changed(edit),retrieved and deleted.For any data area retrieving is only possible by some programming only.
REAL TIME Usage is in stock marketing gold silver and some metal rates will daily updated for only that purpose there is no need to create one program and a database at these points we use these data areas.
The commands to remember are
1.CRTDTAARA :For creation
2.DSPDTAARA :For display
3.CHGDTAARA :for adding and editing
4.RTVDTAARA :For retrieving data
5.DLTDTAARA :For deleting the data area

Now the practice :

1.Creating data area

 1.i.Now how to enter name,library,length,type and initial value in that data area

2.Displaying data area with empty record

 2.i.For entering the details of data area to which we need to display

 2.ii.Now the data area is empty due to no record is added to this

3.Now changing the data in data area by entering some data to data area

3.i.Now see whether data is added to data area or not by using "DSPDTAARA"

4.To see whether data area is created or not use "WRKOBJPDM",data area is object type and no source is available

5.Retrieving is not possible at command level but it is applicable at only programming level some error will show

5.i.Now observe what is the error

6.Now how to delete the data area is by using "DLTDTAARA"

6.i.Now enter the details for data area which is to deleted

6.ii.Now observe the message what will appear when it is deleted