Check whether key appears in the database.

Namespace:  BerkeleyDB
Assembly:  libdb_dotnet48 (in libdb_dotnet48.dll) Version: 4.8.24.0

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

If txn is null and the operation occurs in a transactional database, the operation will be implicitly transaction protected.

Exceptions

ExceptionCondition
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.

See Also