Hi,
Check this link:
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3ca6358411d1829f0000e829fbfe/frameset.htm
Thanks,
Greetson
for input: opens a file on application server for READ and place the cursor at beginning of the file.
for output: open a file on application server for writting it the data set already exists this will place the cursor at the start of the dataset, the old contents get deleted at the end of the program or when the CLOSE DATASET is encountered
for Appending opens the file for writing and places the cursor at the end of the file. if file does not exists then it is generated other wise the new contents will be added at the end of the existing contents.
Hi saritha,
OPEN DATASET statement is used to open a file on the application server,
U have three specific additions such as..
Opening a File for Read Access
Opening a File for Write Access
Opening a File for Appending Data
Opening a File for Read Access
1.To open a file for reading, use the FOR INPUT addition to the OPEN DATASET statement.
Syntax:OPEN DATASET <dataset> FOR INPUT.
The file must already exist, otherwise, the system sets SY-SUBRC to 8, and ignores the statement.
DATA FNAME(60) VALUE 'TEST'.
OPEN DATASET FNAME FOR INPUT.
IF SY-SUBRC = 0.
WRITE / 'File opened'.
.....
ELSE.
WRITE / 'File not found'.
ENDIF.
This example opens the file "TEST" for reading.
2.Opening a File for Write Access
-
To open a file for writing, use the FOR OUTPUT addition to the OPEN DATASET statement.
Syntax: OPEN DATASET <dataset> FOR OUTPUT.
If the file does not already exist, it is created automatically. If it does already exist, but is closed, its contents are overwritten.
DATA FNAME(60) VALUE 'TEST'.
DATA NUM TYPE I.
OPEN DATASET FNAME FOR OUTPUT.
DO 5 TIMES.
NUM = NUM + 1.
TRANSFER NUM TO FNAME.
ENDDO.
PERFORM INPUT.
OPEN DATASET FNAME FOR OUTPUT.
NUM = 0.
DO 5 TIMES.
NUM = NUM + 10.
TRANSFER NUM TO FNAME.
ENDDO.
PERFORM INPUT.
CLOSE DATASET FNAME.
OPEN DATASET FNAME FOR OUTPUT.
NUM = 0.
DO 5 TIMES.
NUM = NUM + 20.
TRANSFER NUM TO FNAME.
ENDDO.
PERFORM INPUT.
FORM INPUT.
SKIP.
OPEN DATASET FNAME FOR INPUT.
DO.
READ DATASET FNAME INTO NUM.
IF SY-SUBRC <> 0.
EXIT.
ENDIF.
WRITE / NUM.
ENDDO.
ENDFORM.
3.Opening a File for Appending Data
To open a file so that you can append data to the end of it, use the FOR APPENDING addition in the OPEN DATASET statement:
Syntax : OPEN DATASET <dataset> FOR APPENDING.
This statement opens a file to which you can append data. If the file does not already exist, it is created automatically. If it does exist, but is closed, the system opens it, and sets the position to the end of the file.
DATA FNAME(60) VALUE 'test'.
DATA NUM TYPE I.
OPEN DATASET FNAME FOR OUTPUT.
DO 5 TIMES.
NUM = NUM + 1.
TRANSFER NUM TO FNAME.
ENDDO.
OPEN DATASET FNAME FOR INPUT.
OPEN DATASET FNAME FOR APPENDING.
NUM = 0.
DO 5 TIMES.
NUM = NUM + 10.
TRANSFER NUM TO FNAME.
ENDDO.
OPEN DATASET FNAME FOR INPUT.
DO.
READ DATASET FNAME INTO NUM.
IF SY-SUBRC <> 0.
EXIT.
ENDIF.
WRITE / NUM.
ENDDO.
generally INPUT is used to read the flatfile..and OUTPUT is used to write data to the flatfile..and APPENDING is used to append the data to already existing file..
Hope u might have got the clear idea.
regards
shankar
normally flat files will be kept on the presentation servers. for more security flat files
will be kept on the application server. when we want to do some operations on the files
present in the application server like READING,WRITING or OVERWRITING we use open dataset
statements. To open a file on the application server, OPEN DATASET statement is used.
it has three options FOR INPUT,FOR OUTPUT,FOR UPDATE.
basic syntax for open dataset statement is OPEN DATASET <filename>. This statement
accompanied by necessary additions depending upon the requirement.
OPEN DATASET FOR INPUT:- To read the contents in a file which is present in an application server we use
OPEN DATASET FOR INPUT. The syntax for OPEN DATASET FOR INPUT is OPEN DATASET <filename> FOR INPUT.
This statement only works when the file really exists in the application server.
OPEN DATASET FOR OUTPUT:- we use this statement whenever we want dump the contents into a file
present in the application server.The syntax for that is OPEN DATASET <filename> FOR OUTPUT.
when the specified filename is not present in the application server then a file with a name
specified in the OPEN DATASET STATEMENT is created and the contents will dumped into that
file.
OPEN DATASET FOR APPENDING:- This statement is used when we want to add new data to a file
which is already having data on the application server. The new data will added at the end
of the file. The syntax for this statement is OPEN DATASET <filename> FOR APPENDING.
here also if the necessary file is not present in the application server is not present then
a file with a name specified in the OPEN DATASET STATEMENT is created and the data is dumped
into that file.
hi
i am trying to read more than 1 files . I am having this issue with abap code.i have like more than 100 files but program is abending reading after 50files..
Program failing in open dataset error can u help me please?
143
144 * Each file is getting into an internal table
>>> OPEN DATASET w_file FOR INPUT IN TEXT MODE ENCODING DEFAULT.
146 IF sy-subrc <> 0.
147 CONTINUE.
148 ELSE.
149 DO.
150 READ DATASET w_file INTO s700_delta.
What command I should give here
Error analysis
An exception occurred that is explained in detail below.
The exception, which is assigned to class 'CX_SY_TOO_MANY_FILES', was not
caught and
therefore caused a runtime error.
The reason for the exception is:
The maximum number of open files (100) has been exceeded.
can u help me
Hello,
After you finish with the file you need to close it
close dataset w_file.
HI saritha,
The below link will give you a clear idea.
[Basic Form of the OPEN DATASET Statement.|http://help.sap.com/saphelp_nw04/helpdata/EN/fc/eb3c8c358411d1829f0000e829fbfe/frameset.htm]
Regards
DKS
