topic Re: Incremental read on DB table in Application Development and Automation Discussions

Incremental read on DB table

Former Member — Mon, 03 Sep 2007 11:45:32 GMT

Hello,

I’m looking for a way to define the ‘

entry point

’ at the incremental read
using select clause like:

Select * from {table} up to {m} rows
               where key-field1 = field1
               and     key-field2 = field2
               …
               and     key-fieldn = fieldn.

I will read rows, after next rows and so on.

How can I determine the correct where-condition to do realize an

incremental read

Thanks and best regards,

Kurt.

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 11:47:34 GMT

HI,

Why dont u use PACKAGE SIZE in the select query?

Thanks and Best Regards,

Vikas Bittera.

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:08:55 GMT

Hello Vikas Bittera,

Thank you for your reply.

That’s clear; I can use package size as well as up to n rows, but I’m looking for the right way how to formulate the where-condition; if I have only one key, so I just can use where key > key. But if I have more key elements so I need a (complex) logical expression.

Do you have any idea?

Thanks and best regards,

Kurt

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:12:30 GMT

Hi,

you need not to do so, as the records will come sorted by the primary key when u will use package size..

Thanks and Best Regards,

Vikas Bittera.

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:13:37 GMT

Do you have any example?

Thanks & best regards,

Kurt.

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:18:29 GMT

Hi,

SELECT vbeln erdat

FROM vbak

INTO TABLE li_vbak PACKAGE SIZE 50.

SELECT posnr matnr meins

FROM vbap

INTO TABLE li_vbap

FOR ALL ENTRIES IN li_vbak

WHERE vbeln = li_vbak-vbeln.

IF sy-subrc = 0.

Now you have the two internal tables li_vbak and li_vbap filled
with data.
Do something with the data - remember to reinitialize internal
tables

ENDIF.

ENDSELECT.

Thanks and Best Regards,

Vikas Bittera.

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:26:58 GMT

Unfortunately I cannot use select…endselect, because I need a set of data to process IDOCs and posting data, I guess I cannot perform commit while select… endselect.

Is there another method to realize this?

Thanks and best regards,

Kurt

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 12:35:47 GMT

If you use Packet size, you do not need to specify number of rows or special keys - just give the full select and it returns a new packet of record each time it loops between the select and endselect statements.

Andrew

Re: Incremental read on DB table

RaymondGiuseppi — Mon, 03 Sep 2007 12:43:18 GMT

You should define a CURSOR and then read the data package via this cursor.

* Declare cursor
DATA s_cursor TYPE cursor.
* Open Cursor (select)
      OPEN CURSOR WITH HOLD s_cursor FOR
        Select * from {table} 
               where key-field1 = field1
               and     key-field2 = field2
               …
               and     key-fieldn = fieldn.
* Then Fetch the data 
DO.
  FETCH NEXT CURSOR s_cursor
               INTO TABLE t_data
               PACKAGE SIZE package_size.
  IF SY-SUBRC <> 0. " No more data
    EXIT.
  ELSE.
    " Work with the data read
  ENDIF.
ENDDO.
* When you have read all the data, close the cursor
      CLOSE CURSOR s_cursor.

Regards

Re: Incremental read on DB table

Former Member — Mon, 03 Sep 2007 13:10:23 GMT

Hi,

You are absolutely correct!! in this case you cannot use package size..

you can do one thing... take one of the main key fields, and fetch the data for a range of this key field at a time and process...

suppose that i want to process the data for 1 to 100 comany codes, i will process 10 company codes at a time..

Thanks and Best Regards,

Vikas Bittera.