lock objects in Abap

[Former Member]

Hi Experts,

What are lock objects in Abap and what are they used for?

Could you give me info.

Regards

Adette

[former_member188829]

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.

Hope this will give a basic idea.

Message was edited by:

Vishnu Reddy

[Former Member]

check this.

http://help.sap.com/saphelp_40b/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm

[Former Member]

Hi,

Lock objects are the ENQUEUE and DEQUEUE for tables and table entries.

You can also create your own lock object, but the way of defining a custom lock object is different.

It should not start with Y or Z as the first character, it should start with a E and then followed by Y or Z to mean that the lock object is a custom lock object.

For eg: you can create a lock object for material no. like EZMATNR.

Regards

Subramanian

[anversha_s]

Hi,

Lock objects are used to lock the database table while making the modifications on the database table.

you can create your own lock objects using SE11.

if you create lock objects on any table system will create two function modules.

1.ENQUEUE....

2.DEQUEUE.....

first one is used to lock the table

second one used to removing lock on the table.

*----

---

lock Table

CALL FUNCTION 'ENQUEUE_E_TABLE'
EXPORTING
tabname = table_name
EXCEPTIONS
foreign_lock = 1
system_failure = 2
OTHERS = 3.

*----

---

Unlock Table

CALL FUNCTION 'DEQUEUE_E_TABLE'
EXPORTING
tabname = table_name

check this link :

http://help.sap.com/saphelp_40b/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm

_SCOPE = 1: The lock is not sent to the update program. The lock is removed when the transaction is ended.

_SCOPE = 2: The lock is sent to the update program. The update program is responsible for removing the lock. The dialog program which requested the lock no longer has an influence on the lock behavior. This is the standard setting for the ENQUEUE function module.

_SCOPE = 3: The lock is also sent to the update program. The lock must be removed in both the dialog program and by the update program. This is the standard setting for the ENQUEUE function module.

Regards

Anver

[Former Member]

Hi Adette,

Please go through the below mentioned links..For better understanding on Lock Objects.

http://www.sap-img.com/abap/type-and-uses-of-lock-objects-in-sap.htm

http://help.sap.com/saphelp_nw04/helpdata/en/41/7af4c5a79e11d1950f0000e82de14a/content.htm

Regards

Mayank

Please reward points if helpful.

[Former Member]

Dear Adette,

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.

regards.

[Former Member]

Hi Adette,

Lock objects are generally used to lock the object so that like if you are doing any modification in the program and any other guy simultaneausly change your code then this could be a blunder for you as well as in the SAP System.

So when u start modification it locks locks by you and no one would able to do changes

This is the benefit