This chapter describes the hierarchy of DALE's interface classes together with some of their dependencies. Interfaces of some classes are described partially to exclude features which are rarely used and some pre- and postconditions are not very important.
Class | Description |
---|---|
ODBC_ELEMENT * | abstract class which presents the notion of an ODBC access element: environment, connection or statement |
SESSION | presents the notion of an ODBC environment |
DATABASE | presents the notion of an ODBC connection to a data source |
SIMPLE_QUERY * | presents the notion of an ODBC statement |
QUERY | kind of SIMPLE_QUERY which "knows" how to construct, prepare and execute a SQL statement as a kind of ODBC statement |
SQL_SELECT | kind of QUERY which incapsulates SQL SELECT statement |
SQL_INSERT | kind of QUERY which incapsulates SQL INSERT statement |
SQL_UPDATE | kind of QUERY which incapsulates SQL UPDATE statement |
SQL_DELETE | kind of QUERY which incapsulates SQL DELETE statement |
RECORDSET | results from executed ODBC statement in a form of a collection of records |
RS_CURSOR | a cursor for RECORDSET; depending on the chosen scrolling mode, it can be monodirectional, or bidirectional and supports absolute and relational movements in recordset |
RECORD | unit of a recordset; comprised of the FIELDs |
DB_CATALOG * | an abstract DALE'S catalog which "knows" how to fill itself up from different sources (see its effective heirs below) |
TABLES | kind of DB_CATALOG, containing a list of tables are currently presented in the database |
PROCEDURES | kind of DB_CATALOG, containing a list of stored procedures are currently presented in the database |
TYPES | kind of DB_CATALOG, containing a list of tables are currently defined in the database |
FIELDS | kind of DB_CATALOG, containing a list of fields which comprise the database table |
PARAMETERS | kind of DB_CATALOG, containing a list of parameters are currently defined in query, in particular, a stored procedure |
DB_TABLE | an element of the TABLES catalog; besides, this is also a recordset presenting the contents of the corresponding table |
DB_PROCEDURE | an element of the PROCEDURES catalog; besides, this is also a query which allows to execute the corresponding stored procedure and obtain result value |
DB_TYPE | an element of the TYPES catalog |
FIELD | an element of the FIELDS catalog or item of RECORD |
ODBC_STATUS | allows to find out the current ODBC status after a single operation or a group of operations |
ODBC_ERROR_ DESCRIPTION |
description of ODBC error |
QUERY_COMPOSER | provides easy and elegant way to construct typical SQL queries |