TMySQLDataset encapsulates database connectivity for descendant dataset objects.
TMySQLDataSet defines database-related connectivity properties and methods for a dataset.
Applications never use TMySQLDataset objects directly. Instead they use the descendants of TMySQLDataSet, such as TMySQLQuery, TMySQLTable and TMySQLStoredProc, which inherit its database-related properties and methods.
TMySQLDataset descendants provide BDE-like functionality and fully compatible with TDatasource and visual DB-controls. If you need to fetch some data without displaying them you can use high-performance TMySQLDirectQuery component.