Used to indicate when to perform a locking of editing record.
property LockMode: TLockMode default lmNone;
Use the LockMode property to define when to perform locking of an editing record. Locking a record is useful in creating multi-user applications. It prevents modification of a record by several users at the same time. Locking realizes through execution of the SELECT FOR UPDATE statement in Firebird 1.5 and through the UPDATE operation in other database servers.