Use correct bind types for SQLBindCol / SQLFetch (#242)

SQLFetch / SQLExtendedFetch now skip the mdb_sql machinery and use
SQLGetData on their bound columns instead. We rely on mdb_fetch_row
to skip to the correct page without any bindings and then SQLGetData will
do the rest.

SQLFetch will now correctly return SQL_SUCCESS_WITH_INFO if one or more
 bound columns have their data truncated, and will return several kinds of errors
(provided by SQLGetData) that were previously ignored.

Updated the unit test with a SQL_C_LONG type for demonstration purposes.

Fixes #23

src/odbc/odbc.c

@@ -41,7 +41,6 @@ static int _odbc_fix_literals(struct _hstmt *stmt);
 //static int _odbc_get_server_type(int clt_type);
 static int _odbc_get_string_size(int size, SQLCHAR *str);
 
-static void bind_columns (struct _hstmt*);
 static void unbind_columns (struct _hstmt*);
 
 #define FILL_FIELD(f,v,s) mdb_fill_temp_field(f,v,s,0,0,0,0)
@@ -291,6 +290,7 @@ SQLRETURN SQL_API SQLExtendedFetch(
     SQLUSMALLINT      *rgfRowStatus)
 {
 	struct _hstmt *stmt = (struct _hstmt *) hstmt;
+	struct _sql_bind_info *cur = stmt->bind_head;
 
 	TRACE("SQLExtendedFetch");
 	if (fFetchType!=SQL_FETCH_NEXT) {
@@ -302,11 +302,21 @@ SQLRETURN SQL_API SQLExtendedFetch(
 	if (rgfRowStatus)
 		*rgfRowStatus = SQL_SUCCESS; /* what is the row status value? */
 	
-	bind_columns(stmt);
-
 	if (mdb_fetch_row(stmt->sql->cur_table)) {
+		SQLRETURN final_retval = SQL_SUCCESS;
+		while (cur && (final_retval == SQL_SUCCESS || final_retval == SQL_SUCCESS_WITH_INFO)) {
+			/* log error ? */
+			SQLLEN lenbind = 0;
+			SQLRETURN this_retval = SQLGetData(hstmt, cur->column_number, cur->column_bindtype,
+					cur->varaddr, cur->column_bindlen, &lenbind);
+			if (cur->column_lenbind)
+				*(cur->column_lenbind) = lenbind;
+			if (this_retval != SQL_SUCCESS)
+				final_retval = this_retval;
+			cur = cur->next;
+		}
 		stmt->rows_affected++;
-		return SQL_SUCCESS;
+		return final_retval;
 	} else {
 		return SQL_NO_DATA_FOUND;
 	}
@@ -1031,25 +1041,6 @@ SQLRETURN SQL_API SQLExecDirectW(
 }
 #endif // ENABLE_ODBC_W
 
-static void
-bind_columns(struct _hstmt *stmt)
-{
-	struct _sql_bind_info *cur;
-
-	TRACE("bind_columns");
-
-	if (stmt->rows_affected==0) {
-		cur = stmt->bind_head;
-		while (cur) {
-			if (mdb_sql_bind_column(stmt->sql, cur->column_number,
-						cur->varaddr, cur->column_lenbind) == -1) {
-				/* log error ? */
-			}
-			cur = cur->next;
-		}
-	}
-}
-
 static void
 unbind_columns(struct _hstmt *stmt)
 {
@@ -1071,26 +1062,28 @@ SQLRETURN SQL_API SQLFetch(
     SQLHSTMT           hstmt)
 {
 	struct _hstmt *stmt = (struct _hstmt *) hstmt;
+	struct _sql_bind_info *cur = stmt->bind_head;
 
 	TRACE("SQLFetch");
-	/* if we bound columns, transfer them to res_info now that we have one */
-	bind_columns(stmt);
-	//cur = stmt->bind_head;
-	//while (cur) {
-		//if (cur->column_number>0 &&
-			//cur->column_number <= stmt->sql->num_columns) {
-			// if (cur->column_lenbind) *(cur->column_lenbind) = 4;
-		//}
-		//cur = cur->next;
-	//}
 	if ( stmt->sql->limit >= 0 && stmt->rows_affected == stmt->sql->limit ) {
 		return SQL_NO_DATA_FOUND;
 	}
-
 	if (mdb_fetch_row(stmt->sql->cur_table)) {
+		SQLRETURN final_retval = SQL_SUCCESS;
+		while (cur && (final_retval == SQL_SUCCESS || final_retval == SQL_SUCCESS_WITH_INFO)) {
+			/* log error ? */
+			SQLLEN lenbind = 0;
+			SQLRETURN this_retval = SQLGetData(hstmt, cur->column_number, cur->column_bindtype,
+					cur->varaddr, cur->column_bindlen, &lenbind);
+			if (cur->column_lenbind)
+				*(cur->column_lenbind) = lenbind;
+			if (this_retval != SQL_SUCCESS)
+				final_retval = this_retval;
+			cur = cur->next;
+		}
 		stmt->rows_affected++;
 		stmt->pos=0;
-		return SQL_SUCCESS;
+		return final_retval;
 	} else {
 		return SQL_NO_DATA_FOUND;
 	}
@@ -2379,4 +2372,4 @@ static const char * _odbc_get_client_type_name(MdbColumn *col)
 	return NULL;
 }
 
-/** @}*/
+/** @}*/

src/odbc/unittest.c

@@ -160,6 +160,7 @@ int i;
 			  
 	if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) 
 	{
+		long id_value;
 		UCHAR  szCol1[60];
 		SQLLEN length;
 
@@ -179,8 +180,8 @@ int i;
 				szSqlState, szErrorMsg);
 			return 1;
 		}		
+		SQLBindCol(hstmt, 1, SQL_C_LONG, &id_value, sizeof(id_value), NULL);
 		SQLBindCol(hstmt, 3, SQL_CHAR, szCol1, sizeof(szCol1), &length);
-		//SQLBindCol(hstmt, 1, SQL_CHAR, szCol1, 60, NULL);
 	
 		/* Execute statement with first row. */
 
@@ -188,7 +189,7 @@ int i;
 		while ((retcode = SQLFetch(hstmt)) == SQL_SUCCESS)
 		{
 			i++;
-			printf("%d: szCol1 = %s (%d)\n", i, szCol1, (int)length);
+			printf("%d: id = %ld  szCol1 = %s (%d)\n", i, id_value, szCol1, (int)length);
 		}
 		if (retcode != SQL_NO_DATA_FOUND)
 		{