![\"SAP\"](\"http:\/\/oprsteny.cz\/wp-content\/uploads\/SAP.jpg\")
The default behavior is if a person opens table maintenance generator and tries to maintain the table, the table is locked and no one else can maintain the same table at the same time.<\/p>\nThe default behavior is if a person opens table maintenance generator and tries to maintain the table, the table is locked and no one else can maintain the same table at the same time.<\/p>\n
This is because there is a “table-level lock” by default in SAP. This means only one user can maintain any table at a time through SM30 or any transaction that calls table maintenance generator. In the tutorial below you will find out how to replace table level lock with row level lock.
\nBy row-level lock you ensure any number of users can modify the table at same time, but any particular row can be modified by only one user at a time (the first one who accessed the row for maintenance). We will create a transaction for this purpose. This transaction will call our custom report where at first the table lock is deleted and subsequently the table maintenance generator will be called..<\/p>\n
Transaction ZRLOCK will call report ZREP_ROWLOCK where we delete table-level lock on ZROWLOCK and then it calls the table maintenance where only selected rows will be locked. This will ensure that multiple users can access the table at the same time. But rows locked by one user can not be edited by anyone else until this user leaves the table maintenance and releases the row locks.<\/p>\n
Go to SE11 and create new table ZROWLOCK with at least the following fields: MANDT, MATNR, WERKS and activate the table.<\/p>\n
In the top menu go to Utilities – Table Maintenance Generator and create new function group for this table. Generate code for one step\/single screen.<\/p>\n Go to SE11 and create new lock with name as EZROWLOCK Now select all the key fields of table ZROWLOCK<\/p>\n Now save and activate the Lock object. SAP automaticall creates two function modules corresponding to lock object for enqueue and dequeue action on table ZROWLOCK<\/p>\n Go to SE38 and create new report called ZREP_ROWLOCK. Go to SE93 and create new transaction for report ZREP_ROWLOCK<\/p>\n <\/p>\n We have to modify the maintenance screen and its code so it locks only rows the user selected to be edited. Now we add line with new module.<\/p>\n The code inside this module will be as the following<\/p>\n Testing<\/span><\/p>\n Now we are ready for testing. Call the transaction ZROWLOCK create some entries with random values in table. Since we have not maintained any check tables etc, the entered values may be invalid, but in a real scenario maintaining check tables should definitely be considered to be implemented.<\/p>\n Save the changes and leave the transaction.<\/p>\n Now open a new session and in both sessions run TCode ZROWLOCK.<\/p>\n In this we will try to open some existing values for table maintenance.<\/p>\n Note\u00a0all selected entries are opened in change mode.<\/p>\n In \u00a0this session pass a range of materials including the one opened in Session 1.<\/p>\n On the following you can see the row opened previously in Session 1 in edit mode is now disabled for editing. But the remaining rows are all enabled and locked for the current user\/session.<\/p>\n The default behavior is if a person opens table maintenance generator and tries to maintain the table, the table is locked and no one else can maintain the same table at the same time. This is because there is a … Continue reading ![\"Table](\"http:\/\/oprsteny.cz\/wp-content\/uploads\/row_lock01.png\")
<\/a><\/p>\nCall table maintenance generator for the table.<\/h1>\n
<\/a><\/p>\nCreate lock object<\/h1>\n
\nEnter the name of our custom table (ZROWLOCK) and select lock mode (Write)<\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\nCreate report and transaction<\/h1>\n
\nThis code will delete the table-level lock on ZROWLOCK table and call its table maintenance.<\/p>\n*&---------------------------------------------------------------------*\r\n *&\u00a0Report\u00a0\u00a0ZREP_ROWLOCK\r\n *&\r\n *&---------------------------------------------------------------------\r\n *&\u00a0Author \u00a0 \u00a0 \u00a0:\u00a0Miroslav Oprsteny\r\n *&\u00a0Date \u00a0 \u00a0 \u00a0 \u00a0:\u00a02013\/04\/04\r\n *&\u00a0Description\u00a0: Database table row-level lock demo\r\n *&---------------------------------------------------------------------*\r\n REPORT\u00a0\u00a0zrep_rowlock.\r\n* Selection\u00a0screen for\u00a0view\u00a0maintenance\r\n DATA:\u00a0BEGIN\u00a0OF\u00a0selekttab\u00a0OCCURS\u00a01.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\r\n INCLUDE\u00a0STRUCTURE\u00a0vimsellist.\r\n DATA:\u00a0END\u00a0OF\u00a0selekttab,\r\n* Table\u00a0of\u00a0inactive\u00a0CUA\u00a0functions\u00a0for\u00a0view\u00a0maintenance\r\n BEGIN\u00a0OF\u00a0excl_cua_funct\u00a0OCCURS\u00a01.\r\n INCLUDE\u00a0STRUCTURE\u00a0vimexclfun.\r\n DATA:\u00a0END\u00a0OF\u00a0excl_cua_funct.\r\n DATA:\u00a0lt_enq_del\u00a0TYPE\u00a0STANDARD\u00a0TABLE\u00a0OF\u00a0seqg3,\r\n lt_enq_read\u00a0TYPE\u00a0STANDARD\u00a0TABLE\u00a0OF\u00a0seqg7,\r\n lw_enq_read\u00a0TYPE\u00a0seqg7,\r\n lw_enq_del\u00a0TYPE\u00a0seqg3,\r\n lv_subrc\u00a0TYPE\u00a0sy-subrc.\r\n*Read\u00a0all\u00a0the\u00a0lock\u00a0details\u00a0in\u00a0system\r\n CALL\u00a0FUNCTION\u00a0'ENQUE_READ2'\r\n EXPORTING\r\n gclient\u00a0=\u00a0sy-mandt\r\n gname\u00a0\u00a0\u00a0=\u00a0'\u00a0'\r\n guname\u00a0\u00a0=\u00a0'*'\r\n TABLES\r\n enq\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0lt_enq_read.\r\n* Search\u00a0entry\u00a0for table-level\u00a0lock\u00a0for\u00a0our\u00a0table\r\n LOOP\u00a0AT\u00a0lt_enq_read\u00a0INTO\u00a0lw_enq_read\r\n WHERE\u00a0gname\u00a0EQ\u00a0'RSTABLE'\r\n AND\u00a0\u00a0\u00a0garg\u00a0CS\u00a0'ZROWLOCK'.\r\n MOVE-CORRESPONDING\u00a0lw_enq_read\u00a0TO\u00a0lw_enq_del.\r\n APPEND\u00a0lw_enq_del\u00a0TO\u00a0lt_enq_del.\r\n ENDLOOP.\r\n*Delete\u00a0table\u00a0level\u00a0lock\u00a0entry\u00a0for\u00a0our\u00a0table\r\n CALL\u00a0FUNCTION\u00a0'ENQUE_DELETE'\r\n EXPORTING\r\n check_upd_requests\u00a0=\u00a01\r\n IMPORTING\r\n subrc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0lv_subrc\r\n TABLES\r\n enq\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0lt_enq_del.\r\n*Now\u00a0call\u00a0the\u00a0table\u00a0maintenace\u00a0generator.\r\n CALL\u00a0FUNCTION\u00a0'VIEW_MAINTENANCE_CALL'\r\n EXPORTING\r\n action\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0'U'\r\n view_name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0'ZROWLOCK'\r\n show_selection_popup\u00a0=\u00a0'X'\r\n TABLES\r\n dba_sellist\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0selekttab\r\n excl_cua_funct\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0excl_cua_funct.<\/pre>\n
<\/a><\/p>\n<\/a><\/p>\nModify the table maintenance<\/h1>\n
\nRun TCode SE80 and open function group ZROWLOCK and open the one step\/single screen you created using table maintenance generator.<\/p>\n<\/a><\/p>\n<\/a><\/p>\nMODULE\u00a0change_locking\u00a0OUTPUT.\r\n*Call\u00a0the\u00a0function\u00a0module\u00a0corresponding\u00a0to\u00a0the\u00a0lock\u00a0object\u00a0we\u00a0created\r\n\u00a0\u00a0CALL\u00a0FUNCTION\u00a0'ENQUEUE_EZROWLOCK'\r\n\u00a0\u00a0\u00a0\u00a0EXPORTING\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0matnr\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0zrowlock-matnr\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0werks\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0zrowlock-werks\r\n\u00a0\u00a0\u00a0\u00a0EXCEPTIONS\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0foreign_lock\u00a0\u00a0\u00a0=\u00a01\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0system_failure\u00a0=\u00a02\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0OTHERS\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a03.\r\n\u00a0\u00a0IF\u00a0sy-subrc\u00a0NE\u00a00.\r\n*\u00a0row\u00a0is\u00a0locked..hence\u00a0gray..\r\n\u00a0\u00a0\u00a0\u00a0LOOP\u00a0AT\u00a0SCREEN.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0screen-input\u00a0=\u00a00.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0MODIFY\u00a0SCREEN.\r\n\u00a0\u00a0\u00a0\u00a0ENDLOOP.\r\n\u00a0\u00a0ENDIF.\r\nENDMODULE.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\"\u00a0change_locking\u00a0\u00a0OUTPUT<\/pre>\n
<\/a><\/p>\nSession 1<\/h2>\n
<\/a><\/p>\n<\/a><\/p>\nSession 2<\/h2>\n
<\/a><\/p>\n<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"