Check whether key appears in the database.
            
    Namespace: 
   BerkeleyDBAssembly: libdb_dotnet53 (in libdb_dotnet53.dll) Version: 5.3.21.0
Syntax
| C# | 
|---|
public bool Exists( DatabaseEntry key )  | 
| Visual Basic (Declaration) | 
|---|
Public Function Exists ( _ key As DatabaseEntry _ ) As Boolean  | 
| Visual C++ | 
|---|
public: bool Exists( DatabaseEntry^ key )  | 
Parameters
- key
 - Type: BerkeleyDB..::.DatabaseEntry
The key to search for. 
Return Value
True if key appears in the database, false otherwise.
Remarks
            If the operation occurs in a transactional database, the operation
            will be implicitly transaction protected.
            
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. |