Check whether key appears in the database.Namespace: BerkeleyDB
Assembly: libdb_dotnet52 (in libdb_dotnet52.dll) Version: 18.104.22.168
public bool Exists( DatabaseEntry key, Transaction txn, LockingInfo info )
|Visual Basic (Declaration)|
Public Function Exists ( _ key As DatabaseEntry, _ txn As Transaction, _ info As LockingInfo _ ) As Boolean
public: bool Exists( DatabaseEntry^ key, Transaction^ txn, LockingInfo^ info )
- Type: BerkeleyDB..::.DatabaseEntry
The key to search for.
- Type: BerkeleyDB..::.Transaction
If the operation is part of an application-specified transaction, txn is a Transaction object returned from BeginTransaction()()(); if the operation is part of a Berkeley DB Concurrent Data Store group, txn is a handle returned from BeginCDSGroup()()(); otherwise null.
- Type: BerkeleyDB..::.LockingInfo
The locking behavior to use.
Return ValueTrue if key appears in the database, false otherwise.
If txn is null and the operation occurs in a transactional database, the operation will be implicitly transaction protected.
|BerkeleyDB..::.NotFoundException||A NotFoundException is thrown if key is not in the database.|
|BerkeleyDB..::.KeyEmptyException||A KeyEmptyException is thrown if the database is a QueueDatabase or RecnoDatabase database and key exists, but was never explicitly created by the application or was later deleted.|