Locked objects, Locked rows in a table, kind of locks

Well, final question for the day.
I created multiple session using sql plus, and in one session sql plus got lunch, it hour glasses and does nothing. I called up a DBA friend and he opined that it might be becasue one of my sessions has got a lock on a row in a table. I was also told that locks can be table level locks and row level locks.
Please help me understand the below( I did try to read about locks, but atleast after first reading it is more confusing.. in order to update a row in a table why would oracle obtain a table level lock?)
1. What are the different database objects which can get locked ?
2. What are the different kinds of locks and what do they mean?
3. When a row is locked by a session, can we identify that particular session and how ?
4. What is the difference between pessimistic locking and optmistic locking ?
5. Any scripts which I can use to get lock related info from database ?
Gony

1. What are the different database objects which can get locked ?There are locks which oracle acquire on any useful resource. We , as the users are most focussed on tables and their locks. But locks do happen in memory as well.
2. What are the different kinds of locks and what do they mean?http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/dynviews_2.htm#REFRN30121
3. When a row is locked by a session, can we identify that particular session and how ?Sure, there is a default script that comes up, utllockt.sql which can show you. Other than that, you can EM to do so as well. Read this,
4. What is the difference between pessimistic locking and optmistic locking ?http://download.oracle.com/docs/cd/B28359_01/server.111/b28274/instance_tune.htm#sthref748
5. Any scripts which I can use to get lock related info from database ?See #4 above.
HTH
Aman....

Similar Messages

Locking a particular row in a table control

Hi All,
I have module pool program in which table control is used. I would like to know whether it is possible to lock a particular row in the table so that another person will not be able to edit it until the first user completes his work. It should be only for that particular record which is being currently edited in the table.

Hi,
Yes you can lock particular row in a table control..
In the flow logic..
PROCESS BEFORE OUTPUT.
LOOP AT itab INTO wa WITH CONTROL tc.
     MODULE disable_row.
ENDLOOP.
MODULE disable_row.
* call the Enqueue function module..If the
    IF sy-subrc NE 0.
      LOOP AT screen.
           SCREEN-INPUT = 0.    " Disable for input
           MODIFY SCREEN.
      ENDLOOP.
   ENDIF.
ENDMODULE.
Thanks
Naren

Lock object funtion module for afpo table

Hii,
I have designed a screen and maintained batch field as mandatory field in that screen. and when i give batch number and hit enter the order number related to that batch number is automatcially picked. order and batch field's i am taking from AFPO table.now i want to lock this batch or order field so that no 2 user's can use same batch or order number while making entries.
can anyone let me know what is the function module i should use for enqueue and dequeue technics for these 2 fields.
Regards,
Venkat.
Edited by: venkat akella on Jun 29, 2010 1:40 PM

Hi Venkat,
For your requierment, you have to create a lock object for table AFPO using T code SE11.
The name of the Lock object should be start with EZ.
Then use the FM DEQUEUE_EZ**** & ENQUEUE_EZ**** For unlock and lock of the order.
Regards
DKS

Lock Object. Want to see if it's locked.

Hello to everyone.
I have got a question about lock objects.
There is a Z-table in abap dictionary. During the processing of my report some strings from this Z-table are selected. To select strings i use the SELECT statement. But there can appear the situation when two users ( or more) run my transaction, so the same strings can be selected and then processed. To avoid this situation i've created the lock object with cumulative lock mode ( 'X' ) for this Z-table and put the calling of ENQUEUE function into the code. To test the locking i' ve run my report under two different accounts in the debugging mode. And found that when the enqueue function is finished , and the current string should be locked in theory, this string can be easily selected with help of select-statement under another account. (Even when the transactions start with delay.)
How can i lock the string in the Z-table so that it could be selected only once during the earlier launched transaction?
Regards,
alex karpo.

Ho alex,
SAP locking is a cooperative locking model. That means that you have to care for what is possible and what is not possible. You may use enqeue module to set lock for key of every object selected.
If there is already a foreign lock, you should delete the entry from the list or table of selected objects (in memory, not in database).
Or do it as SAP does: If there is a foreign lock, the user is informed and the data can be displayed, not changed.
You can always check the lock by trying to set a lock.
Regards,
Clemens

Let me know creation of lock object

let me know creation of lock object

Hi
Lock Objects
Lock object concept
Lock modes
Creating a lock object (example)
Lock object sample code
SAP data dictionary provides you with a locking mechanism to synchronize simultaneous data access by different users.
Lock objects are created in SE11.
Customer lock objects must begin with EY or EZ .
Three possible lock modes exist for lock objects.
Lock Mode
Lock mode E: This sets a lock for changing data for single user. This lock can be accumulated.
Lock mode X: This mode is used like mode E for changing data. The only technical difference from mode E is that the respective lock does not allow accumulation.
Lock mode S: This mode ensures that data displayed in your program cannot be changed by other users during the entire display time. Here you do not want to change the data yourself (allows read only access for data).
Creating Lock object
SE11
1)Enter lock object name beginning with EY or EZ
and hit create.
2)Enter table names containing data records that should be locked and the lock mode.
Enter short text /tbale/lockmode.
3) The primary keys of the specified tables are automatically selected as lock parameters.
It automatically selects the primary key for the selected table.
To set a lock in the application program
call a function module ENQUEUE_<LOCK_OBJECT>.
For our example, it would be ENQUEUE_EZMARA.
To release the lock in the application program
call a function module DEQUEUE_<LOCK_OBJECT>.
For our example, it would be DEQUEUE_EZMARA.
Refer the code executed by user (say abap1) for
matnr = 000000000000000012.
Lock Objects are used to synchronize access to the same data by more than one user. Function modules that can be used in application programs are generated from the definition of a lock object in the ABAP Dictionary.
The R/3 System synchronizes simultaneous access of several users to the same data records with a lock mechanism. When interactive transactions are programmed, locks are set and released by calling function modules .These function modules are automatically generated from the definition of lock objects in the ABAP Dictionary.
Structure of a Lock Object
The tables in which data records should be locked with a lock request are defined in a lock object together with their key fields.
When tables are selected, one table (the primary table) is first selected. Further tables (secondary tables) can also be added using foreign key relationships.
Lock Arguments
The lock argument of a table in the lock object consists of the key fields of the table.
The lock argument fields of a lock object are used as input parameters in the function modules for setting and removing locks generated from the lock object definition. When these function modules are called, the table rows to be locked or
unlocked are specified by defining certain values in these fields.These values can also be generic. The lock argument fields therefore define which subset of the table rows should be locked
Data Dictionary/ Lock Objects
The simplest case of a lock object consists of exactly one table and the lock argument of the table is the primary key of this table. Several tables can also be included in a lock object. A lock request therefore can lock an entire logical
object, and not only a record of a table. Such a logical object can be for example a document comprising an entry in a header table and N entries in a positiontable.
Lock Mode
The lock mode controls whether several users can access data records at the same time. The lock mode can be assigned separately for each table in the lock object. When the lock is set, the corresponding lock entry is stored in the
lock table of the system for each table. Access by more than one user can be synchronized in the
following ways:
Exclusive lock: The locked data can only be displayed or
edited by a single user. A request for another exclusive lock
or for a
shared lock is rejected.
Shared lock: More than one user can access the locked data
at the same time in display mode. A request for another
shared lock is accepted, even if it comes from another user. An exclusive lock
is rejected. Exclusive but not cumulative: Exclusive locks can be requested
several times from the same transaction and are processed
successively. In contrast, exclusive but not cumulative locks
can be called only once from the same transaction. All other
lock requests are rejected.
1) Select object type Lock object in the initial screen of the ABAP Dictionary, enter an object name and choose Create. The name of a lock object should begin with an E (Enqueue).The maintenance screen for lock objects is displayed.
2) Enter an explanatory short text in the field Short text. You can then use the short text to find the lock object at a later time, for example with the R/3 Repository Information System.
3) Enter the name of the primary table of the lock object. All other tables in the lock object must be linked with the primary table using foreign keys.
4) Select the lock mode of the primary table in the field below it The lock mode is used as the default value for the corresponding parameters of the function modules generated from the lock object.
5) Choose Add if you want to lock records in more than one
table with the lock object. A list of all the tables linked with the primary table using valid foreign keys is displayed. Select the appropriate table. The lock
mode of the primary table is copied as lock mode. You can change this setting as required, for example you can assign the lock mode separately for each table.
Similarly, you can add a table linked with the secondary table just added with foreign keys. To do this, place the cursor on the name of the secondary table and choose Add.
If no lock mode is assigned to a table, no lock is set for the
entries in this table when the generated function modules are
called. You should not assign a lock mode if a secondary table
was only used to define a path between the primary table and
another secondary table with foreign keys.
6) Save your entries.
A dialog box appears in which you have to assign the lock
object a development class.
7) You can define whether the function modules generated from
the lock object should be RFC-enabled on the Attributes tab
page. If you set the Allow RFC flag, the generated function
modules can be called from within another system with Remote
Function Call. If you permit Remote Function Calls for an
existing lock object, you must ensure that the generated
function modules are called from within an ABAP program with
parameters appropriate for the type. You should therefore check
all programs that use the associated function modules before
activating the lock object with the new option.
8) Choose Activate
Reward if u sefull

Lock object for KONV table/Cluster table ??

Hi All,
Is it possible to set Lock/Enqueue cluster tables or in my case table:KONV (KNUMV field) ?.
OSS provided some programs without locks so was hoping if I could add before performing data manipulation.
Regards,
Neeth

Hi Nameeth,
you can use generic lock object E_TABLE with function modules ENQUEUE_E_TABLE, DEQUEUE_E_TABLE for locking and unlocking with parameters table name and key field.
Regards,
Satya

Lock Object (Not locking the table)

Hi Guys
I have a custom table ZDRAD same like standard table DRAD with an additional 'DATE' field . ZDRAD's Key fields are same like DRAD . I have created a lock object 'EZDRAD' where I put name = 'ZDRAD' (Custom table) and mode = 'EXCLUSIVE CUMULATIVE' . Now I want to lock the table(Whole table) before modifying/Inserting/deleting the records in se38. Please check the code below and suggest me if I am passing wrong values to the lock object Function module.
Code
TABLES : ZDRAD.
CALL FUNCTION 'ENQUEUE_EZDRAD'
EXPORTING
 MODE_ZDRAD = 'E'
 MANDT = SY-MANDT
 DOKAR = ' '
 DOKNR = ' '
 DOKVR = ' '
 DOKTL = ' '
 DOKOB = ' '
 OBZAE = 0
 OBJKY = ' '
 X_DOKAR = ' '
 X_DOKNR = ' '
 X_DOKVR = ' '
 X_DOKTL = ' '
 X_DOKOB = ' '
 X_OBZAE = ' '
 X_OBJKY = ' '
 _SCOPE = '2'
 _WAIT = 'X'
 _COLLECT = ' '
EXCEPTIONS
 FOREIGN_LOCK = 1
 SYSTEM_FAILURE = 2
 OTHERS = 3
*IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
 WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
*ENDIF.
IF SY-SUBRC = 0.
ZDRAD table is locked.
 P_L_LOCK_STAT = 'X'.
 EXIT.
ELSE.
ZDRAD table is not locked
 CLEAR P_L_LOCK_STAT .
ENDIF.

Hi Kanthimathi
That is numeric field . Please suggest me how can i check the lock.

Lock object for table EKES

Hi experts,
I developed a function module to update the confirmations tab of a PO on ME22N screen. Now, I want to have a lock object in the FM so that a user cant make changes while this FM is in use. I do not know if there is any standard lock object for this purpose. I created a lock object in SE11 'EZEKES' since table EKES corresponds to vendor confirmations details. The Enqueue function was called into the program. The code is below:
CALL FUNCTION 'ENQUEUE_EZPHLOCK'
EXPORTING
 MODE_EKES = 'E'
 MANDT = SY-MANDT
 EBELN = ponumber
EXCEPTIONS
 FOREIGN_LOCK = 1
 SYSTEM_FAILURE = 2
 OTHERS = 3
The problem is, i'm not able to have a lock on the confirmations tab when the FM is in use. Is there any problem with the lock object i have created. The lock mode is Exclusive,Cumulative.
Please help me with this.

Code:
""Local Interface:
*" IMPORTING
*" REFERENCE(PONUMBER) TYPE EKKO-EBELN
*" TABLES
*" ITAB STRUCTURE UEKES
TABLES: EKES, EKKO.
DATA: BEGIN OF I_EKKO OCCURS 0,
 EBELN LIKE EKKO-EBELN,
 END OF I_EKKO.
DATA: X LIKE EKES-ETENS.
data: i_tab like itab occurs 0 with header line.
move itab[] to i_tab[].
DATA: i_ekes LIKE uekes OCCURS 0 WITH HEADER LINE.
SELECT EBELN FROM EKKO INTO TABLE I_EKKO WHERE EBELN = PONUMBER.
IF NOT I_EKKO[] IS INITIAL.
 SELECT * FROM EKES INTO TABLE I_EKES
 FOR ALL ENTRIES IN I_EKKO
WHERE EBELN = I_EKKO-EBELN.
ENDIF.
select single etens from ekes into x WHERE EBELN = PONUMBER.
x = x + 1.
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
 WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
DATA: VARKEY LIKE RSTABLE-VARKEY.
CALL FUNCTION 'ENQUEUE_E_TABLE'
 EXPORTING
 MODE_RSTABLE = 'E'
 TABNAME = EKES
 VARKEY = VARKEY
 X_TABNAME = ' '
 X_VARKEY = ' '
 _SCOPE = '2'
 _WAIT = ' '
 _COLLECT = ' '
EXCEPTIONS
 FOREIGN_LOCK = 1
 SYSTEM_FAILURE = 2
 OTHERS = 3
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
 WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
 WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
 LOOP AT I_TAB. "WHERE EBELN = PONUMBER.
 READ TABLE I_TAB.
 LOOP AT i_ekes WHERE ebelp EQ ITAB-EBELP "itemnumber
 AND ebtyp EQ 'LA'.
 i_ekes-menge = ITAB-MENGE. "quantity.
 i_ekes-kz = 'U'.
 i_ekes-eindt = ITAB-EINDT. "deldate.
 I_EKES-XBLNR = ITAB-XBLNR.
 i_ekes-erdat = sy-datum.
 i_ekes-ezeit = sy-uzeit.
 MODIFY i_ekes.
 ENDLOOP.
ENDLOOP.
IF sy-subrc NE 0.
 LOOP AT I_TAB. "WHERE EBELN = PONUMBER.
 READ TABLE I_TAB.
 LOOP AT i_ekes WHERE ebelp EQ ITAB-EBELP "itemnumber
 AND ebtyp EQ 'AB'.
 i_ekes-menge = ITAB-MENGE. "quantity.
 i_ekes-ebtyp = 'LA'.
 i_ekes-kz = 'I'.
 i_ekes-etens = x.
 i_ekes-eindt = ITAB-EINDT. "deldate.
 I_EKES-XBLNR = ITAB-XBLNR.
 i_ekes-erdat = sy-datum.
 i_ekes-ezeit = sy-uzeit.
 APPEND i_ekes.
 ENDLOOP.
 ENDLOOP.
ENDIF.
To update the confirmations tab
CALL FUNCTION 'ME_CONFIRMATION_UPDATE'
 EXPORTING
 I_EBELN = PONUMBER
 TABLES
 XEKES = i_ekes[].
 YEKES = I_EKES[].
IF SY-SUBRC = 0.
 CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'.
ENDIF.
CALL FUNCTION 'DEQUEUE_E_TABLE'
EXPORTING
MODE_RSTABLE = 'E'
 TABNAME = EKES.
 VARKEY = VARKEY
X_TABNAME = ' '
X_VARKEY = ' '
_SCOPE = '3'
_SYNCHRON = ' '
_COLLECT = ' '
ENDFUNCTION.

Lock object problem on custom table

Hi all.
I am having a bit of an issue with a lock object on a home made table. We're using the UWL and a custom IView to display an extended invoice. No problem releasing the workitem lock, just the table entry lock.
I can see the lock in SM12. Tried dequeue/dequeue all RFCs from backend, no luck.
The lock is set from a custom RFC. This RFC succesfully releases the lock when used in SAPGUI, and we have an RFC enabled wrapper around it. However, once used in the portal, the locks aren't released. My suspicion is that it has to do with sessions and I can't see a way to control that since dynpro uses a connection pool IIRC.
Anyone have any ideas on how to solve this?

Small correction if you are not aware. Do not create your custom tables in APPS schema? Custom tables are supposed to created in custom schema such as XXPO and a synonym created for the table in APPS schema.
When creating an EO, you do not need to provide the schema name. You would need to enter only the table name.
Hope this helps.

Error while lock object creation

Hi
When I tried to create a lock object, I get the following error.
Error: "Total length of lock argument for table XXXXXXXXX longer than 150"
I have 3 tables in which Table1 is the check table for the value tables (Table2 & Table3). During the process of deletion of a record from Table1 (CT) I need the lock tobe established on value tables and then I delete all the corresponding entries in value tables are also deleted.
Would like to know If there is any other std ways of doing this ? and
Solution to overcome the error.
Regards
Karthick

Hi,
I think the error is becoz you have given too many LOCK parameters in the lock object. the total length of the PARAMTERS of lock object should not exceed 150.
By default all the KEY fields will be taken as Lock paramters, so your table key's length is more than 150.
Also why dont you create 3 lock objects for each table and then use only KEY's of each table as LOCK PARAMETERS.
Then Lock T1 record first then lock T2 and T3 records, then delete records from T2 and T3.
Then you delete T1 record.
The execute DEQUEUE_ALL.
Regards,
Sesh

About lock object

I have one TABLE with TABLE MAINTENANCE GENERATOR
and it has also LOCK OBJECT.
Now I have adjusted the table by making some normal fields as primary keys
and regenerated Table maintenance generator ,
It seems to me lock object also adjusted( I am able to see the newly converted primary key fields in lock object( in se11 ) ).
Does the lock object automatically adjusts ????
If lock object adjusts automatically --> what about the function modules ENQUEUE_ztable DEQUEUE_ztable ? these function modules also gets adjusted ?
do I need to check the associated lock object impact ?
How can I check ?

Hi,
No need to delete the Lock object. Just remove the Table which you modified from Lock object & add again. You can add the lock Parameters manually. It will be drived automatically from Table key fields.
You no need to delete the lock object.
Raja T
Message was edited by:
Raja T

Differeence between Lock object and enqueue_e_table

Hi ,
what is diff between Lock object and enque_e_table. Where to use enqueue_e_table and where to use lock object.
I think with a lock object i can lock more than one table (passing tables in secondary table). Please correct me.

A lock object does not really "lock a table" though most of lock objects refer to a database table.
I explain:
The principle is that when 2 programs lock at the same time with the same lock object, only the first will succeed.
If you have a program which does not use the lock, it may update the database table without any problem.
All programs which update a table have to use the same lock object. Note that users are always able to update this table via SM30 as they don't know the lock object to be used.
enqueue_xxxx is the name of the generated function module used to lock the xxxx lock object. E_TABLE lock is ONLY used by SM30 if I remember well, so that to prevent one table from being updated via SM30 by 2 persons at the same time. But it is not related at all with programs which would also update this table.
Edited by: Sandra Rossi on Mar 14, 2010 9:53 PM

Lock objects

Hi experts,
My requirement is to create lock for parent table and its child tables.Each and every child tables is having relation with the parent table.
When iam creating the lock for parent table, in this process iam adding the child tables in the list.But here one child table is missing in the log eventhough its having the relation with parent table.
Valuable replies will be awarded with points.........
Regards,
Swetha.

Hi,
it may help u
1) Select object type Lock object in the initial screen of the ABAP Dictionary, enter an object name and choose Create. The name of a lock object should begin with an E (Enqueue).The maintenance screen for lock objects is displayed.
2) Enter an explanatory short text in the field Short text. You can then use the short text to find the lock object at a later time, for example with the R/3 Repository Information System.
3) Enter the name of the primary table of the lock object. All other tables in the lock object must be linked with the primary table using foreign keys.
4) Select the lock mode of the primary table in the field below it The lock mode is used as the default value for the corresponding parameters of the function modules generated from the lock object.
5) Choose Add if you want to lock records in more than one
table with the lock object. A list of all the tables linked with the primary table using valid foreign keys is displayed. Select the appropriate table. The lock
mode of the primary table is copied as lock mode. You can change this setting as required, for example you can assign the lock mode separately for each table.
Similarly, you can add a table linked with the secondary table just added with foreign keys. To do this, place the cursor on the name of the secondary table and choose Add.
If no lock mode is assigned to a table, no lock is set for the
entries in this table when the generated function modules are
called. You should not assign a lock mode if a secondary table
was only used to define a path between the primary table and
another secondary table with foreign keys.
6) Save your entries.
A dialog box appears in which you have to assign the lock
object a development class.
7) You can define whether the function modules generated from
the lock object should be RFC-enabled on the Attributes tab
page. If you set the Allow RFC flag, the generated function
modules can be called from within another system with Remote
Function Call. If you permit Remote Function Calls for an
existing lock object, you must ensure that the generated
function modules are called from within an ABAP program with
parameters appropriate for the type. You should therefore check
all programs that use the associated function modules before
activating the lock object with the new option.
8) Choose Activate
Regards

Lock Object Creation

Hi,
Is it possible to create lock objects at runtime? if not, how do I lock tables at runtime when the table name is specified in the selection screen by the user?
Thanks.
Tyken

Hi tyken,
Try this.
Lock Objects are Created using Tcode SE11.
The Lock object name must be start with EZur name.
Mainly lock objects are used for locking the transactions, tables --etec.
Multiple users can not updated the same transaction at the same time.
Whenever u create a lock object using se11. SAP internally
creates a two function modules:
Enqueue_lockobjname ---For Locking purpose,
dequeue_lockobjname---For Unlocking purpose.
U make use of these fms to lock and unlock transctions, tables..etc.
Steps to create lock objects :
GO TO SE11
Select the radio button "Lock object"..
Give the name starts with EZ or EY..
Example: EYTEST
Press Create button..
Give the short description..
Example: Lock object for table ZTABLE..
In the tables tab..Give the table name..
Example: ZTABLE
Save and generate..
Your lock object is now created..You can see the LOCK MODULES..
In the menu ..GOTO -> LOCK MODULES..There you can see the ENQUEUE and DEQUEUE function
The example is as follws:
EPORT ZLOCK_UNLOCK
MESSAGE-ID ZBDC.
TABLES ZSTUD.
DATA text(8) TYPE c.
CALL SCREEN 100.
*& Module USER_COMMAND_0100 INPUT
text
MODULE USER_COMMAND_0100 INPUT.
CASE SY-UCOMM.
WHEN 'SELECT'.
SELECT SINGLE * FROM ZSTUD WHERE ROLLNO = ZSTUD-ROLLNO.
MESSAGE i004 WITH 'SY-SUBRC:' sy-subrc.
WHEN 'EXIT'.
LEAVE PROGRAM.
WHEN 'ENQUEUE'.
CALL FUNCTION 'ENQUEUE_EZLOCK1'
EXPORTING
MODE_ZSTUD = 'X'
ROLLNO = ZSTUD-ROLLNO
EXCEPTIONS
FOREIGN_LOCK = 1
SYSTEM_FAILURE = 2
OTHERS = 3.
CASE sy-subrc.
WHEN 0.
MESSAGE i004 WITH 'Enqueue successful'(001).
WHEN 1.
text = sy-msgv1.
MESSAGE e004 WITH 'Record already'(002) 'locked by'(003)
text.
CALL TRANSACTION 'SM12'.
WHEN 2 OR 3.
MESSAGE e004 WITH 'Error in enqueue!'(004)
'SY-SUBRC:' sy-subrc.
ENDCASE.
WHEN 'DEQUEUE'.
CALL FUNCTION 'DEQUEUE_EZLOCK1'
EXPORTING
MODE_ZSTUD = 'X'
ROLLNO = ZSTUD-ROLLNO
EXCEPTIONS
OTHERS = 1.
CASE sy-subrc.
WHEN 0.
MESSAGE i004 WITH 'Dequeue successful'(005).
WHEN 1.
MESSAGE e004 WITH 'Error in dequeue!'(006).
ENDCASE.
WHEN 'SM12'.
CALL TRANSACTION 'SM12'.
ENDCASE.
ENDMODULE. " USER_COMMAND_0100 INPUT
*& Module STATUS_0100 OUTPUT
text
MODULE STATUS_0100 OUTPUT.
SET PF-STATUS 'BASIC'.
ENDMODULE. " STATUS_0100 OUTPUT
Regards,
Chitra

How to create a lock object in se11

hi all,
Can anyone tell me the step by step procedure to lock as well as unlock a particular object in se11 trns code. with an real time example.
thanxs in advance
hari

Hi,
Lock objects are use in SAP to avoid the inconsistancy at the time of data is being insert/change into database.
SAP Provide three type of Lock objects.
- Read Lock(Shared Locked)
protects read access to an object. The read lock allows other transactions read access but not write access to
the locked area of the table
- Write Lock(exclusive lock)
protects write access to an object. The write lock allows other transactions neither read nor write access to
the locked area of the table.
- Enhanced write lock (exclusive lock without cumulating)
works like a write lock except that the enhanced write lock also protects from further accesses from the
same transaction.
You can create a lock on a object of SAP thorugh transaction SE11 and enter any meaningful name start with EZ Example EZTEST_LOCK.
Use: you can see in almost all transaction when you are open an object in Change mode SAP could not allow to any other user to open the same object in change mode.
Example: in HR when we are enter a personal number in master data maintainance screen SAP can't allow to any other user to use same personal number for changes.
Technicaly:
When you create a lock object System automatically creat two function module.
1. ENQUEUE_<Lockobject name>. to insert the object in a queue.
2. DEQUEUE_<Lockobject name>. To remove the object is being queued through above FM.
You have to use these function module in your program.
Creating Lock Objects
Procedure
1.Select object type Lock object in the initial screen of the ABAP Dictionary, enter an object name and choose Create. The name of a lock object should begin with an E (Enqueue).
The maintenance screen for lock objects is displayed.
2.Enter an explanatory short text in the field Short text.
You can then use the short text to find the lock object at a later time, for example with the R/3 Repository Information System.
3.Enter the name of the primary table of the lock object.
All other tables in the lock object must be linked with the primary table using foreign keys. There are also some restrictions on the valid foreign key relationships.
4.Select the lock mode of the primary table in the field below it.
The lock mode is used as the default value for the corresponding parameters of the function modules generated from the lock object.
5.Choose Add if you want to lock records in more than one table with the lock object.
A list of all the tables linked with the primary table using valid foreign keys is displayed. Select the appropriate table. The lock mode of the primary table is copied as lock mode. You can change this setting as required, for example you can assign the lock mode separately for each table.
6.Similarly, you can add a table linked with the secondary table just added with foreign keys. To do this, place the cursor on the name of the secondary table and choose Add.
7.If no lock mode is assigned to a table, no lock is set for the entries in this table when the generated function modules are called. You should not assign a lock mode if a secondary table was only used to define a path between the primary table and another secondary table with foreign keys.
8.Save your entries.
A dialog box appears in which you have to assign the lock object a development class.
9.You can (optionally) exclude lock parameters (see lock objects) from the function module generation on the Lock parameter tab page. This makes sense for example if you always want to lock a parameter generically.
To do this, simply deselect the Weight flag for the parameter. The parameter is not taken into consideration in the generated function modules. This parameter is then always locked generically.
9.The name of a lock parameter is usually the name of the corresponding table field. If two fields with the same name are used as lock parameters in the lock object from different tables, you must choose a new name for one of the fields in field Lock parameter.
10.You can define whether the function modules generated from the lock object should be RFC-enabled on the Attributes tab page.
If you set the Allow RFC flag, the generated function modules can be called from within another system with Remote Function Call.
11.If you permit Remote Function Calls for an existing lock object, you must ensure that the generated function modules are called from within an ABAP program with parameters appropriate for the type. You should therefore check all programs that use the associated function modules before activating the lock object with the new option.
12 .Choose Activate .
Result
When you activate the lock object, the two function modules ENQUEUE_<lockobjectname> and DEQUEUE_<lockobjectname> are generated from its definition to set and release locks.
You can find information about the activation flow in the activation log, which you can display with Utilities Activation log. If errors occurred during activation, the activation log is displayed immediately.
Pls reward points.
Regards,
Ameet
Message was edited by:
Ameet Jassani

Locked objects, Locked rows in a table, kind of locks

Similar Messages

Maybe you are looking for