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The QMRecordlock function locks a record. It is analogous to the QMBasic RECORDLOCKL and RECRODLOCKU statements.
Format
| VB | QMRecordlock ByVal FileNo as Integer, ByVal Id as String, ByVal Update as Integer, |
ByVal Wait as Integer
| C | void QMRecordlock(int FileNo, char * Id, int Update, int Wait) |
| Obj | Session->Recordlock(FileNo, Id, Update, Wait) |
where
| FileNo | is the file number returned by a previous QMOpen() call. |
| Id | is the id of the record to be locked. |
| Update | is a boolean value specifying the type of lock to be obtained: |
| Wait | is a boolean value indicating the action to be taken if the record is currently locked by another user: |
| True | wait for the record to become available |
| False | return an error code of SV_LOCKED |
The QMRecordlock function can be used to obtain a lock on a record without reading the record.
Examples
VB
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QMRecordllock(fClients, ClientNo, True, True)
QMWrite fClients, ClientNo, Rec
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C
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QMRecordlock(fClients, ClientNo, TRUE, TRUE);
QMWrite(fClients, ClientNo, Rec2);
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QMBasic
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session->Recordlock(fClients, ClientNo, @true, @true)
session->Write(fClients, Id, Rec)
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The above program fragment writes a new record into the file opened as fClients. To comply with recommended locking rules, a record should never be written unless the program holds an update lock on it. Use of QMRecordlock() gets this lock before the write.
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