[libgda] MySQL provider: handle statements where the prepared statement API doe snot work

[Vivien Malerba <vivien src gnome org>]

commit fe504de1a4991b454571bf9c8959b069c6ea141b
Author: Vivien Malerba <malerba gnome-db org>
Date:   Fri Oct 29 15:56:37 2010 +0200

    MySQL provider: handle statements where the prepared statement API doe snot work
    
    it seems some statements can't be used with MySQL's prepared statament API,
    and then one gets the "This command is not supported in the prepared statement protocol yet"
    error, see http://bugs.mysql.com/bug.php?id=6415

 providers/mysql/gda-mysql-provider.c |   85 ++++++++++++++++++++++++----------
 providers/mysql/gda-mysql.h          |    1 +
 2 files changed, 62 insertions(+), 24 deletions(-)
---
diff --git a/providers/mysql/gda-mysql-provider.c b/providers/mysql/gda-mysql-provider.c
index 04d580f..2f825c3 100644
--- a/providers/mysql/gda-mysql-provider.c
+++ b/providers/mysql/gda-mysql-provider.c
@@ -1819,9 +1819,11 @@ gda_mysql_provider_statement_prepare (GdaServerProvider  *provider,
 static GdaMysqlPStmt *
 prepare_stmt_simple (MysqlConnectionData  *cdata,
 		     const gchar          *sql,
-		     GError              **error)
+		     GError              **error,
+		     gboolean *out_protocol_error)
 {
 	GdaMysqlPStmt *ps = NULL;
+	*out_protocol_error = FALSE;
 	g_return_val_if_fail (sql != NULL, NULL);
 
 	MYSQL_STMT *mysql_stmt = mysql_stmt_init (cdata->mysql);
@@ -1839,6 +1841,8 @@ prepare_stmt_simple (MysqlConnectionData  *cdata,
 	
 	if (mysql_stmt_prepare (mysql_stmt, sql, strlen (sql))) {
 		_gda_mysql_make_error (cdata->cnc, NULL, mysql_stmt, error);
+		if (mysql_stmt_errno (mysql_stmt) == ER_UNSUPPORTED_PS)
+			*out_protocol_error = TRUE;
 		mysql_stmt_close (mysql_stmt);
 		ps = NULL;
 	}
@@ -2098,12 +2102,50 @@ gda_mysql_provider_statement_execute (GdaServerProvider               *provider,
 			 */
 			gchar *sql = gda_mysql_provider_statement_to_sql (provider, cnc, stmt, 
 									  params, 0, NULL, error);
+			gboolean proto_error;
 			if (!sql)
 				return NULL;
-			ps = prepare_stmt_simple (cdata, sql, error);
+			ps = prepare_stmt_simple (cdata, sql, error, &proto_error);
+			if (!ps) {
+				if (proto_error) {
+					/* MySQL's "command is not supported in the prepared
+					 * statement protocol yet" error
+					 * => try to execute the SQL using mysql_real_query() */
+					GdaConnectionEvent *event;
+					if (mysql_real_query (cdata->mysql, sql, strlen (sql))) {
+						event = _gda_mysql_make_error (cnc, cdata->mysql, NULL, error);
+						gda_connection_add_event (cnc, event);
+						g_free (sql);
+						return NULL;
+					}
+
+					g_free (sql);
+					my_ulonglong affected_rows;
+					/* Create a #GdaSet containing "IMPACTED_ROWS" */
+					/* Create GdaConnectionEvent notice with the type of command and impacted rows */
+					affected_rows = mysql_affected_rows (cdata->mysql);
+					if (affected_rows == (my_ulonglong)~0) {
+						TO_IMPLEMENT;
+						return (GObject *) gda_data_model_array_new (0);
+					}
+					else {
+						gchar *str;
+						event = gda_connection_point_available_event (cnc, GDA_CONNECTION_EVENT_NOTICE);
+						str = g_strdup_printf ("%llu", affected_rows);
+						gda_connection_event_set_description (event, str);
+						g_free (str);
+						
+						gda_connection_internal_statement_executed (cnc, stmt, params, event); /* required: help @cnc keep some stats */
+						return (GObject *) gda_set_new_inline
+							(1, "IMPACTED_ROWS", G_TYPE_INT, (int) affected_rows);
+					}
+				}
+				else {
+					g_free (sql);
+					return NULL;
+				}
+			}
 			g_free (sql);
-			if (!ps)
-				return NULL;
 		}
 		else {
 			ps = (GdaMysqlPStmt *) gda_connection_get_prepared_statement (cnc, stmt);
@@ -2479,11 +2521,13 @@ gda_mysql_provider_statement_execute (GdaServerProvider               *provider,
 	}
 	else {
 		/* execute prepared statement using C API depending on its kind */
-		if (!g_ascii_strncasecmp (_GDA_PSTMT (ps)->sql, "SELECT", 6) ||
+		my_ulonglong affected_rows;
+		affected_rows = mysql_stmt_affected_rows (ps->mysql_stmt);
+		if ((affected_rows == (my_ulonglong)~0) ||
+		    !g_ascii_strncasecmp (_GDA_PSTMT (ps)->sql, "SELECT", 6) ||
 		    !g_ascii_strncasecmp (_GDA_PSTMT (ps)->sql, "SHOW", 4) ||
 		    !g_ascii_strncasecmp (_GDA_PSTMT (ps)->sql, "DESCRIBE", 8) ||
 		    !g_ascii_strncasecmp (_GDA_PSTMT (ps)->sql, "EXPLAIN", 7)) {
-			
 			if (mysql_stmt_store_result (ps->mysql_stmt)) {
 				_gda_mysql_make_error (cnc, NULL, ps->mysql_stmt, error);
 			}
@@ -2500,27 +2544,20 @@ gda_mysql_provider_statement_execute (GdaServerProvider               *provider,
 			}
 		}
 		else {
-			my_ulonglong affected_rows = (my_ulonglong)~0;
 
 			/* Create a #GdaSet containing "IMPACTED_ROWS" */
 			/* Create GdaConnectionEvent notice with the type of command and impacted rows */
-			affected_rows = mysql_stmt_affected_rows (ps->mysql_stmt);
-			if (affected_rows >= 0) {
-				GdaConnectionEvent *event;
-                                gchar *str;
-                                event = gda_connection_point_available_event (cnc, GDA_CONNECTION_EVENT_NOTICE);
-                                str = g_strdup_printf ("%llu", affected_rows);
-                                gda_connection_event_set_description (event, str);
-                                g_free (str);
-
-                                return_value = (GObject *) gda_set_new_inline
-                                        (1, "IMPACTED_ROWS", G_TYPE_INT, (int) affected_rows);
-
-				gda_connection_internal_statement_executed (cnc, stmt, params, event); /* required: help @cnc keep some stats */
-			}
-			else {
-				return_value = (GObject *) gda_data_model_array_new (0);
-			}
+			GdaConnectionEvent *event;
+			gchar *str;
+			event = gda_connection_point_available_event (cnc, GDA_CONNECTION_EVENT_NOTICE);
+			str = g_strdup_printf ("%llu", affected_rows);
+			gda_connection_event_set_description (event, str);
+			g_free (str);
+			
+			return_value = (GObject *) gda_set_new_inline
+				(1, "IMPACTED_ROWS", G_TYPE_INT, (int) affected_rows);
+			
+			gda_connection_internal_statement_executed (cnc, stmt, params, event); /* required: help @cnc keep some stats */
 
 			if (last_inserted_row) {
 				my_ulonglong last_row;
diff --git a/providers/mysql/gda-mysql.h b/providers/mysql/gda-mysql.h
index aa3f0b5..ef3ba9b 100644
--- a/providers/mysql/gda-mysql.h
+++ b/providers/mysql/gda-mysql.h
@@ -33,6 +33,7 @@
 #include <winsock.h>
 #endif
 #include <mysql.h>
+#include <mysqld_error.h>
 #include <gda-mysql-reuseable.h>
 
 /*