added ODBC support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@299 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/iodbc/hdbc.h

@@ -0,0 +1,67 @@
+#ifndef	_HDBC_H
+#define	_HDBC_H
+
+typedef	struct DBC
+{
+	int	type;		/* must be 1st field */
+	struct DBC FAR*	
+		next;
+
+	HENV	genv;		/* back point to global env object */
+
+	HDBC	dhdbc;		/* driver's private dbc */
+	HENV	henv;		/* back point to instant env object */
+	HSTMT	hstmt;		/* list of statement object handle(s) */
+	HERR	herr;
+
+	int	state;
+
+	/* options */
+	UDWORD	access_mode;
+	UDWORD	autocommit;
+
+	UDWORD	login_timeout;
+	UDWORD	odbc_cursors;
+	UDWORD	packet_size;
+	UDWORD	quiet_mode;
+	UDWORD	txn_isolation;
+	SWORD	cb_commit;
+	SWORD	cb_rollback;
+
+	char FAR*	
+		current_qualifier;
+
+	int	trace;	/* trace flag */
+	char FAR*	
+		tfile;
+	void FAR*
+		tstm;	/* trace stream */
+} DBC_t;
+
+/* 
+ * Note:
+ *  - ODBC applications can see address of driver manager's 
+ *    connection object, i.e connection handle -- a void pointer, 
+ *    but not detail of it. ODBC applications can neither see 
+ *    detail driver's connection object nor its address.
+ *
+ *  - ODBC driver manager knows its own connection objects and
+ *    exposes their address to an ODBC application. Driver manager
+ *    also knows address of driver's connection objects and keeps
+ *    it via dhdbc field in driver manager's connection object.
+ * 
+ *  - ODBC driver exposes address of its own connection object to
+ *    driver manager without detail.
+ *
+ *  - Applications can get driver's connection object handle by
+ *    SQLGetInfo() with fInfoType equals to SQL_DRIVER_HDBC.
+ */
+
+enum	{
+	en_dbc_allocated,
+	en_dbc_needdata,
+	en_dbc_connected,
+	en_dbc_hstmt
+};
+
+#endif