open dataset???

[deepak_kumar11]

Hi all,

what is the use of statement open data set

can u explain this code & its significance:-

OPEN CURSOR WITH HOLD G_CURSOR FOR

SELECT VBAK~VBELN

VBAP~POSNR

FROM VBAK

INNER JOIN VBUK

ON VBUK_{VBELN = VBAK}VBELN

INNER JOIN VBAP

ON VBAP_{VBELN = VBAK}VBELN

INNER JOIN VBUP

ON VBUP_{VBELN = VBAP}VBELN

AND VBUP_{POSNR = VBAP}POSNR

INNER JOIN VBEP

ON VBEP_{VBELN = VBAP}VBELN

AND VBEP_{POSNR = VBAP}POSNR

WHERE VBAK~VBELN IN S_VBELN

AND VBAK~AUART IN S_AUART

AND VBAP~MATNR IN S_MATNR

AND VBAP~WERKS IN S_WERKS

AND VBAP~MATKL IN S_MATKL

AND VBAP~ABGRU EQ SPACE

AND VBEP~MBDAT IN S_MBDAT

AND VBUK~LFSTK <> 'C'

AND VBUP~LFSTA <> 'C'.

DO.

FETCH NEXT CURSOR G_CURSOR

INTO TABLE LT_DATA PACKAGE SIZE P_PACK.

IF SY-SUBRC <> 0.

• nothing found anymore => EXIT

CLOSE CURSOR G_CURSOR.

EXIT.

ELSE.

SORT LT_DATA BY VBELN POSNR.

APPEND LINES OF LT_DATA TO LT_DATA1.

.

CLEAR : LT_DATA, LT_DATA[].

ENDIF.

ENDDO.

Regards

Deepak

[Former Member]

Hi Deepak,

Open Dataset is used for open the file in Aplication Server.

OPEN DATASET dset FOR access IN mode [position]

[ os_addition]

[error_handling].

Effect

This statement opens the file specified in dset for the access specified in access in a storage mode specified in mode. For dset, a character-type data object is expected, which contains the platform-specific name of the file.

Use additions position, os_addition and error_handling to determine the position at which to open the file, to specify platform-specific additions and to influence error handling.

In Unicode programs, the access and storage modes access and mode must be specified explicitly. If the additions are missing in non-Unicode programs, the file is opened implicitly as a binary file for read access.

In Unicode programs, the file must not yet be open in the current program; otherwise a treatable exception occurs. In non-Unicode programs, the file may already be open. The statement OPEN DATASET then does not reopen the file but moves the read or write position depending on the access mode. In this case, you should not change the access or storage mode.

so when we want to read data from application server we write teh command.

OPEN DATASET <DATASET NAME> FOR INPUT IN TEXT MODE ENCODING DEFAULT.

When we want to write the data into appication server we write like this

OPEN DATASET <DATASET NAME> FOR OUTPUT IN TEXT MODE ENCODING DEFAULT.

also have a look at the below links.

http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3ca6358411d1829f0000e829fbfe/content.htm

Thanks.

[Former Member]

Data set is a file in the application server.

In BDC concept when we are working with the file in the application server,

We open the file for different reasons(read/write/append) using this concept.

Syn: open dataset <filename> for <input/output/append> in <text/binary> mode encoding default.

Here,

Input is for reading the file from Application server

output is for writing the file into Application server

append is for adding more info to the existing file.

******************************************************

OPEN DATASET, is to open a file in application server.

We can open a file in application server to READ or WRITE or APPEND data.

Below extract the documenation can easily help you understand the same:

OPEN DATASET

Basic form 1

OPEN DATASET dsn.

Extras:

1a. ... FOR INPUT

1b. ... FOR OUTPUT

1c. ... FOR APPENDING

1d. ... FOR UPDATE

2a. ... IN BINARY MODE

2b. ... IN TEXT MODE [ENCODING (DEFAULT|UTF-8|NON-UNICODE)]

2c. ... IN LEGACY BINARY MODE [(BIG|LITTLE) ENDIAN] [CODE PAGE cp]

2d. ... IN LEGACY TEXT MODE [(BIG|LITTLE) ENDIAN] [CODE PAGE cp]

3. ... REPLACEMENT CHARACTER rc

4. ... IGNORING CONVERSION ERRORS

5. ... AT POSITION p

6. ... TYPE c

7. ... MESSAGE m

8. ... FILTER f

In some cases, the syntax rules that apply to Unicode programs are different than those for non-Unicode programs. For details see the section File Interface.

Effect

Opens the specified file. If you do not specify a directory, the system uses the directory defined in the profile parameter DIR_HOME.

In programs without active Unicode check, the file is opened for reading in binary mode if you do not use any additions for OPENDATASET. To ensure downward compatibility with Releases <= 4.6, file names containing blanks are truncated at the position of the first blank.

In programs with active Unicode check, you must specify the access type (such as ... FOR INPUT, ... FOR OUTPUT, and so on) and the mode (such as ... IN TEXT MODE, ... IN BINARY MODE, and so on). If the file is opened using ... IN TEXT MODE, you must still use the addition ... ENCODING. If the Unicode check is enabled, it is possible to use file names containing blanks. Applying OPEN DATASET to a file already opened - in the same internal mode - triggers an exception of the type CX_SY_FILE_OPEN.

The Return Code is set as follows:

SY-SUBRC = 0:

The file was opened.

SY-SUBRC = 8:

The file could not be opened.

Example

DATA:

dsn(20) TYPE C VALUE '/usr/test.dat',

rec(80) TYPE C.

OPEN DATASET dsn FOR INPUT IN TEXT MODE ENCODING DEFAULT.

IF sy-subrc <> 0.

EXIT.

ENDIF.

READ DATASET dsn INTO rec.

WHILE sy-subrc <> 0.

WRITE / rec. READ DATASET dsn INTO rec.

ENDWHILE.

CLOSE DATASET dsn.

The system opens the file test.dat in the directory usr of the application server and reads it line by line.

Notes

The system must be able to reach the file from the current application server. You cannot edit files from the current presentation server. If you need to do this, use the function modules GUI_DOWNLOAD and GUI_UPLOAD.

The form of the file name depends on the underlying operating system. To make your programs portable to different operating systems, use the function module FILE_GET_NAME, which returns the system-dependent name for an abstract file name. You can define file names using the transaction FILE.

The system automatically performs an authorization check. If this check fails, a runtime error occurs. You can prevent this by checking the authorization in advance using the function module AUTHORITY_CHECK_DATASET.

Note

Access rights to files:

When you create a file, it is created under the user name used to start the SAP System. This is not usually the name of the current user. To allow the system to create files, you must assign write authorization to the user name of the SAP System in the relevant directory.

Addition 1a

... FOR INPUT

Effect

OPEN ... FOR INPUT opens the file in read mode.

If the file does not exist, OPEN ... FOR INPUT fails with Return Code SY-SUBRC = 8.

Note

If OPEN DATASET is not executed in a Unicode program and if the user has write authorization for the file, the file is opened in read and write mode. Otherwise, it is only opened in read mode.

Addition 1b

... FOR OUTPUT

Effect

OPEN ... FOR OUTPUT opens the file in write mode.

If the file already exists, its existing content is deleted. If the file does not exist, the system creates it.

Addition 1c

... FOR APPENDING

Effect

OPEN ... FOR APPENDING opens the file in append mode.

If the file already exists, its contents are retained, and the system moves to the end of the file. If the file does not exist, the system creates it. If the file was already open, the system moves to the end of the file.

Note

When you open a file using FOR APPENDING, READDATASET always returns Return Code SY-SUBRC = 4 which is used to display the end of the file.

Addition 1d

... FOR UPDATE

Effect

OPEN ... FOR UPDATE opens the file in read and write mode.

If the file does not exist, OPEN ... FOR UPDATE fails with Return Code SY-SUBRC = 8.

Addition 2a

... IN BINARY MODE

Effect

Data is read or written unchanged (as stored in the memory). (For details, see READ DATASET and TRANSFER.)

This file format is used if you do not specify a MODE addition.

Addition 2b

... IN TEXT MODE [ENCODING (DEFAULT|UTF-8|NON-UNICODE)]

Effect

Data is read or written line by line. (For details, see READ DATASET and TRANSFER.)

Note

on ENCODING (DEFAULT|UTF-8|NON-UNICODE)

This addition specifies the character representation in the file:

DEFAULT

Corresponds to UTF-8 in Unicode systems and to NON-UNICODE in non-Unicode systems.

UTF-8

Characters are represented in the file in the format UTF-8.

NON-UNICODE

Characters are represented in the file in the code page defined by the text environment current at the time a READ or TRANSFER command is executed (see SET LOCALE LANGUAGE).

Addition 2c

... IN LEGACY BINARY MODE [(BIG|LITTLE) ENDIAN] [CODE PAGE cp]

Effect

Data is read or written in a form which is compatible to BINARY MODE in Releases <= 4.6. This addition is primarily used to convert a file into the code page format specified already when it is opened. At runtime, the system uses the format of the system code page of the application server. The system saves the file then again in the code page specified. This procedure is important if data is exchanged between systems using different code pages. For more information, see READ DATASET and TRANSFER.

Addition 2d

... IN LEGACY TEXT MODE [(BIG|LITTLE) ENDIAN] [CODE PAGE cp]

Effect

Data is read or written in a form which is compatible to BINARY MODE in Releases <= 4.6. This addition is primarily used to convert a file into the code page format specified already when it is opened. At runtime, the system uses the format of the system code page of the application server. The system saves the file then again in the code page specified. This procedure is important if data is exchanged between systems using different code pages. For more information, see READ DATASET and TRANSFER.

Notes

on BIG ENDIAN, LITTLE ENDIAN

These additions specify the byte sequence in which to store numbers (ABAP types I, F, and INT2) in the file.

These additions may only be used in combination with the additions IN LEGACY BINARY MODE and IN LEGACY TEXT MODE. If these are not specified, the system assumes that the byte sequence determined by the hardware of the application server is used in the file.

If the byte sequence specified differs from that determined by the hardware of the application server, READDATASET and TRANSFER make the corresponding conversions.

These additions replace the language element TRANSLATE ... NUMBER FORMAT ... which must not be used in Unicode programs.

on CODE PAGE cp

This addition specifies the code page which is used to represent texts in the file.

This addition may only be used in combination with the additions IN LEGACY BINARY MODE and IN LEGACY TEXT MODE. If this addition is not specified, the system uses the code page defined by the text environment current at the time a READ or TRANSFER command is executed (see SET LOCALE LANGUAGE).

This addition replaces the language element TRANSLATE ... CODE PAGE ... which must not be used in Unicode programs.

Addition 3

... REPLACEMENT CHARACTER rc

Effect

Specifies the replacement character which is used when a character cannot be converted during a character set conversion.

Note

This addition may only be used in combination with the additions IN TEXT MODE and IN LEGACY ... MODE. If the addition is not specified, "#" is used as the replacement character.

Addition 4

... IGNORING CONVERSION ERRORS

Effect

This addition ensures that no exception is triggered when an error occurs during character set conversion and a file is accessed in read or write mode. If you do not use this addition, the exception CX_SY_CONVERSION_CODEPAGE is triggered when a conversion error occurs. (For details see READ DATASET and TRANSFER.)

Addition 5

... AT POSITION p

Effect

Sets the read/write position in the file to p. p is interpreted as the byte offset from the beginning of the file.

Notes

You can use the command GETDATASET POSITION to access the current read/write position. This value can be used as the parameter p for the AT POSITION addition.

When you use the OPEN ... FOR OUTPUT AT POSITION ... variant, the file contents are destroyed if the file already existed. To prevent this from happening, use OPEN ... FOR UPDATE AT POSITION ... if you want to change an existing file at the position specified.

Addition 6

... TYPE c

Effect

You can specify additional file attributes in the field c. The field contents are passed to the operating system without changes and without any checks for correctness. For more information on the correctness of the attributes specified, refer to the open system call documentation of the relevant operating system.

Note

If the application server runs under Windows NT and the file was opened using IN TEXT MODE or IN LEGACY TEXTMODE, the TYPE addition is interpreted as follows:

c = 'NT'

The end of the line is marked with "CRLF".

c = 'UNIX'

The end of the line is marked with "LF".

Other

The addition is ignored, and the end of the line is marked with the line end character possibly already used in the file (see the note at the end of this document).

Example

Generating the OS/400 file test.dat with the properties specified under TYPE. The following example specifies the record length, the block size, and the record format.

OPEN DATASET 'test.dat'

TYPE 'lrecl=80, blksize=8000, recfm=FB'

FOR OUTPUT IN TEXT MODE ENCODING DEFAULT.

Addition 7

... MESSAGE m

Effect

If an error occurs opening the file, the corresponding message of the operating system is stored in the field m.

Example

DATA: dsn(20) VALUE '/usr/test.dat',

msg(100).

OPEN DATASET dsn FOR INPUT MESSAGE msg

IN TEXT MODE ENCODING DEFAULT.

IF sy-subrc <> 0.

WRITE / msg.

STOP.

ENDIF.

Addition 8

... FILTER f

Effect

If you are working under UNIX or Windows NT, you can specify an operating system command in the field f.

Example

Under UNIX, the following

DATA dsn(20) VALUE '/usr/test.dat'.

OPEN DATASET dsn FOR OUTPUT FILTER 'compress'

IN TEXT MODE ENCODING DEFAULT.

opens the file dsn and writes the data to the file in compressed form using the UNIX command compress.

OPEN DATASET dsn FOR INPUT FILTER 'uncompress'

IN TEXT MODE ENCODING DEFAULT.

reads the file again.

Exceptions

Catchable Exceptions

CX_SY_FILE_OPEN

Cause: The file is already open (only in Unicode programs)

Runtime Error: DATASET_REOPEN

CX_SY_CODEPAGE_CONVERTER_INIT

Cause: The required conversion is not supported (because you specified an invalid code page or a language with SET LOCALE LANGUAGE not supported during conversion).

Runtime Error: CONVT_CODEPAGE_INIT (catchable)

CX_SY_CONVERSION_CODEPAGE

Cause: Internal conversion error

Runtime Error: CONVT_CODEPAGE (catchable

CX_SY_FILE_AUTHORITY

Cause: No authorization to access a file

Runtime Error: OPEN_DATASET_NO_AUTHORITY (catchable)

Cause: Authorization to access this file missing for OPEN DATASET with addition FILTER.

Runtime Error: OPEN_PIPE_NO_AUTHORITY (catchable)

CX_SY_PIPES_NOT_SUPPORTED

Cause: OPEN DATASET with addition FILTER is not supported on the current operating system.

Runtime Error: DATASET_NO_PIPE (catchable)

CX_SY_TOO_MANY_FILES

Cause: The maximum number of open files has been exceeded.

Runtime Error: DATASET_TOO_MANY_FILES (catchable)

Non-Catchable Exceptions

Cause: You attempted to open a pipe already open.

Runtime Error: DATASET_PIPE_POSITION

Note

End of line marking under Windows NT

Since under Windows NT the line end in text files can be marked both with " CRLF" and with "LF", text files are handled in a special way on this operating system when opened using FOR OUTPUT or FOR APPENDING:

You can use the addition TYPE to specify the desired end of line marking.

If you do not specify an end of line marking using the addition TYPE, the system searches the file (if it exists already) for end of line markings. The first marking found is used for future search operations.

If the file does not already exist or if no marking is found, the format specified in the profile parameter "abap/NTfopen" is used.

If the profile parameter is not set, "CRLF" is used.

[Former Member]

Hi Deepak

Please let me know whether you want to know about Open cursor or Open dataset ...

Open Dataset opens the cursor which can be used later for fetching data from the DB tables.

Open Dataset is used to open the file in the application server for reading or writing.

~Ranganath

Reward points for all useful answers !!

[Former Member]

hi,

To open a file on the application server, use the OPEN statement as follows:

Syntax:

OPEN DATASET <dsn> [Additions].

This statement opens the file <dsn>. If you do not specify any additions for the mode, the file is opened in binary mode for reading. SY-SUBRC returns 0 if the system opens the file. Otherwise, SY-SUBRC is set to 8.

You enter the filename <dsn> either as a literal or as a field containing the actual name of the file. If you do not specify a path, the system opens the file in the directory in which the R/3 System is running on the application server. To open a file, the user under which the R/3 System is running must have the requisite authorizations at operating system level.

example:

DATA FNAME(60).

FNAME = '/tmp/myfile'.

OPEN DATASET 'myfile'.

OPEN DATASET FNAME.

This example works as long as your R/3 System is running under UNIX. The program opens the file "myfile" in the directory in which the R/3 System is running, and also opens the file "myfile" in directory "/tmp". However, you would have to change the filename for other operating systems. For example, for OpenVMS, you could write the following:

FNAME = '[TMP]myfile.BIN'

OPEN DATASET 'myfile.BIN'.

please reward if it is useful.