topic Re: Lock TABLES in Application Development and Automation Discussions

Lock TABLES

Former Member — Wed, 09 Apr 2008 07:10:37 GMT

Hi,

May I know how do i lock WHOLE Table, without letting anyone to write data?

I have created lock entries called EZZVPAFINAL, but the same transaction still allow data to write into the table, as long as none records are same. How can I prevent totally none records are able to update the table, as long as there is one connection to the table.

CALL FUNCTION 'ENQUEUE_EZZVPAFINAL'

EXPORTING

MODE_ZVPAFINAL = 'E'

MANDT = SY-MANDT

ZVBELN = IT_ZVPA-ZVBELN

ZVKORG = IT_ZVPA-ZVKORG

ZVTWEG = IT_ZVPA-ZVTWEG

ZPOSNR = IT_ZVPA-ZPOSNR

ZMATNR = IT_ZVPA-ZMATNR

ZPLANT = IT_ZVPA-ZPLANT

X_ZVBELN = ' '
X_ZVKORG = ' '
X_ZVTWEG = ' '
X_ZPOSNR = ' '
X_ZMATNR = ' '
X_ZPLANT = ' '
_SCOPE = '2'
_WAIT = ' '
_COLLECT = ' '

EXCEPTIONS

FOREIGN_LOCK = 1

SYSTEM_FAILURE = 2

OTHERS = 3

CASE sy-subrc.

WHEN 0.

MESSAGE i888 WITH 'Enqueue successful'(001).

WHEN 1.

CALL TRANSACTION 'SM12'.

WHEN 2 OR 3.

ENDCASE.

Re: Lock TABLES

Former Member — Wed, 09 Apr 2008 07:20:20 GMT

Hi Hui,

I guess SAP locks are created at application server level and not at database level.

Even though you create locks on the table, the other program should also try create a lock then only SAP throws an error, else it allows other program to update the data.

For Example:

1. prog1 locks data1

2. prog2 tries to lock data and update

3. prog3 tries to update data without lock.

In this scenarai, prog2 will get a error and prog3 will update the table.

So Ensure that whatever program tries to update the data should first acquire the lock.

Hope this helps you.

Thanks,

Arun

Re: Lock TABLES

Former Member — Wed, 09 Apr 2008 07:34:13 GMT

Hi,

Do you mean check if there is lock on the table first before processing?

Re: Lock TABLES

Former Member — Wed, 09 Apr 2008 07:37:28 GMT

Hi Hui,

Yes that is a must.

Whenever you update a database table, you check whether it is locked or not.

Thanks,

Arun

Re: Lock TABLES

Former Member — Wed, 09 Apr 2008 09:53:06 GMT

JUST A QUESTION,

may i know how do i check in abap code whether there is a lock on the table?

is there any specific table to read?

Re: Lock TABLES

Former Member — Wed, 09 Apr 2008 10:03:22 GMT

LOCK OBJECTS

1)Go to se11 transaction.

2)Click on lock object radio button and give a lock object name starting with 'E'.For example 'ESAMPLE'.Click CREATE.

3)In the TABLE tab, you can give the table name for which you require a lock.In the LOCK PARAMETERS tab,you can give the table fields based on which the table should be locked.

4)Call a function module in your program ENQUEUE_lockobjectname to obtain a lock on the required table.In our example the FM will be ENQUEUE_ESAMPLE.

5)To release the lock on the table,call the function module DEQUEUE_lockobjectname.In our example the FM will be DEQUEUE_ESAMPLE.

Regards

Sreeni