Check whether key appears in the database.
            
    Namespace: 
   BerkeleyDBAssembly: libdb_dotnet53 (in libdb_dotnet53.dll) Version: 5.3.28.0
 Syntax
Syntax
| C# | 
|---|
| 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 | 
| Visual C++ | 
|---|
| public: bool Exists( DatabaseEntry^ key, Transaction^ txn, LockingInfo^ info ) | 
Parameters
- key
- Type: BerkeleyDB..::.DatabaseEntry
 The key to search for.
- txn
- 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.
- info
- Type: BerkeleyDB..::.LockingInfo
 The locking behavior to use.
Return Value
True if key appears in the database, false otherwise. Remarks
Remarks
            If txn is null and the operation occurs in a
            transactional database, the operation will be implicitly transaction
            protected.
            
 Exceptions
Exceptions
| Exception | Condition | 
|---|---|
| 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. | 





