| TQDataBrowser | Data manipulation and navigation for data entry forms | 
| TQDataTable | Flexible SQL table widget that supports browsing and editing | 
| TQDataView | Read-only SQL forms | 
| TQEditorFactory | Used to create editor widgets for TQVariant data types | 
| TQSql | Namespace for TQt SQL identifiers that need to be global-like | 
| TQSqlCursor | Browsing and editing of SQL tables and views | 
| TQSqlDatabase | Used to create SQL database connections and to provide transaction handling | 
| TQSqlDriver | Abstract base class for accessing SQL databases | 
| TQSqlEditorFactory | Used to create the editors used by TQDataTable and TQSqlForm | 
| TQSqlError | SQL database error information | 
| TQSqlField | Manipulates the fields in SQL database tables and views | 
| TQSqlFieldInfo | Stores meta data associated with a SQL field | 
| TQSqlForm | Creates and manages data entry forms tied to SQL databases | 
| TQSqlIndex | Functions to manipulate and describe TQSqlCursor and TQSqlDatabase indexes | 
| TQSqlPropertyMap | Used to map widgets to SQL fields | 
| TQSqlQuery | Means of executing and manipulating SQL statements | 
| TQSqlRecord | Encapsulates a database record, i.e. a set of database fields | 
| TQSqlRecordInfo | Encapsulates a set of database field meta data | 
| TQSqlResult | Abstract interface for accessing data from SQL databases | 
| TQSqlSelectCursor | Browsing of general SQL SELECT statements |