| |
| Berkeley DB .NET API Documentation |
| BaseDatabase..::.Exists Method (DatabaseEntry, Transaction, LockingInfo) |
| BaseDatabase Class See Also |
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
| 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. |
