# Package org.h2.api

Contains interfaces for user-defined extensions, such as triggers and user-defined aggregate functions.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  Aggregate | A user-defined aggregate function needs to implement this interface.
  AggregateFunction | A user-defined aggregate function needs to implement this interface.
  CredentialsValidator | A class that implement this interface can be used to validate credentials provided by client.
  DatabaseEventListener | A class that implements this interface can get notified about exceptions and other events.
  JavaObjectSerializer | Custom serialization mechanism for java objects being stored in column of type OTHER.
  TableEngine | A class that implements this interface can create custom table implementations.
  Trigger | A class that implements this interface can be used as a trigger.
  UserToRolesMapper | A class that implement this interface can be used during authentication to map external users to database roles.

- Class Summary
  Class | Description
  --- | ---
  ErrorCode | This class defines the error codes used for SQL exceptions.
  H2Type | Data types of H2.
  Interval | INTERVAL representation for result sets.

- Enum Summary
  Enum | Description
  --- | ---
  IntervalQualifier | Interval qualifier.

## Package org.h2.api Description

Contains interfaces for user-defined extensions, such as triggers and user-defined aggregate functions.