如何识别其他用户在正在进行的记录打开中获得的锁 [英] How to identify the lock acquired by another user on a record in progress openedge
问题描述
用户A已从客户表中读取了第一条记录.用户B希望知道A保留在记录上的锁. B将如何以编程方式识别用户A持有的锁.
User A has read first record from a customer table. User B wishes to know the lock which is held by A on the record. How will B identify the lock held by User A programmatically.
推荐答案
您可以使用内置的_Lock虚拟系统表.
You can use the built in _Lock Virtual System Table.
这是一个基本示例:
DEFINE TEMP-TABLE ttLock
FIELD LockId LIKE _Lock._Lock-Id
FIELD LockUsr LIKE _Lock._Lock-Usr
FIELD LockName LIKE _Lock._Lock-Name
FIELD LockTable LIKE _Lock._Lock-Table
FIELD LockFlags LIKE _Lock._Lock-flags
INDEX LockIdx IS PRIMARY UNIQUE LockId.
FOR EACH _Lock NO-LOCK:
IF _Lock._Lock-Usr = ? THEN NEXT .
CREATE ttLock.
ASSIGN
LockId = _Lock._Lock-Id
LockUsr = _Lock._Lock-Usr
LockName = _Lock._Lock-Name
LockTable = _Lock._Lock-Table
lockFlags = _Lock._Lock-flags.
END.
FOR EACH ttlock:
FIND _Trans NO-LOCK WHERE _Trans._Trans-Usrnum = ttLock.LockUsr NO-ERROR.
FIND _File NO-LOCK WHERE _File-Number = ttLock.LockTable.
MESSAGE
"Transaction Id:~t" (IF AVAILABLE _Trans THEN _Trans._Trans-Id ELSE ?) "~n"
"User Number:~t" ttLock.LockUsr "~n"
"User Name~t" ttLock.LockName "~n"
"Table Number:~t" ttLock.LockTable "~n"
"Table Name:~t" _File-Name "~n"
"Flags:~t" ttLock.LockFlags
VIEW-AS ALERT-BOX INFO BUTTONS OK.
END.
(直接来自此知识库中的条目.)
在数据库管理指南中,您可以看到(第848),您可以看到_Lock.LockFlags中的标志代表什么.
In the Database Administration guide you can see (page 848) you can see what the flags in _Lock.LockFlags stand for.
锁标记-标志指定共享 锁(S),排他锁(X),已升级的锁 从共享到独占(U),处于边缘状态(L), 排队的锁(Q),锁跨过 事务结束边界(K),锁是其中的一部分 一个JTAtransaction(J),锁处于创建模式 JTA(C)或锁定等待超时已过期 在此排队锁(E)上
Flags for the lock—the flags specify a share lock (S), exclusive lock (X), a lock upgraded from share to exclusive(U), a lock in limbo (L), a queued lock(Q), a lock kept across transaction end boundary (K), a lock is part of a JTAtransaction (J), a lock is in create mode for JTA (C), or a lockwait timeout has expired on this queued lock (E)
查询_Lock表可能只是您要在测试环境中执行的操作.根据您的系统大小,那里可能有很多数据.另外,使用VST进行只读操作!
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