SqlExpr

TCustomSQLDataSet encapsulates the properties, events, and methods for working with data accessed through dbExpress. Applications should not instantiate TCustomSQLDataSet objects. Instead, instantiate one of the descendant classes: TSQLDataSet, TSQLTable, TSQLQuery, or TSQLStoredProc. 

TCustomSQLDataSet and its descendants represent unidirectional datasets. Unlike other datasets, unidirectional datasets do not buffer multiple records in memory. Because of this, they have the following limitations: 

There is no searching or navigation support except for moving to the first record or moving to the next record. 

There is no built-in editing support. The data underlying an SQL dataset can only be edited by explicitly creating an SQL UPDATE command or by connecting the SQL dataset to a client dataset using a provider. 

There is no support for filtering records or for lookup fields. 

TSQLDataSet 

TSQLQuery 

TSQLStoredProc 

TSQLTable 

TSQLConnection 

TClientDataSEt 

TDataSEtProvider