This example demonstrates how to debug MySQL stored procedure by stepping into the stored procedure. It also illustrates different debugging techniques such as setting breakpoints, viewing data items, and so on.
In this topic, some sample database objects are used for demonstrating how to work with the Fusion for MySQL Debugger. Use scripts specified in this topic to create necessary objects in your test database.
Use the script available in Sample Script to Create Database Tables to create necessary tables.
Use the script below to create the procedure that takes two input parameters: DateFrom and DateTo. Based on these input parameters the schedule_list table fills up with data.
CREATE PROCEDURE FillSchedule (IN DateFrom date
, IN DateTo date
, IN ScheduleId int)
SQL SECURITY INVOKER
READS SQL DATA
BEGIN
DECLARE DateOut date;
DECLARE TemplateCount tinyint;
DECLARE RowNumber tinyint;
DECLARE TimeSheetDate date;
SET
TemplateCount = (SELECT
COUNT(*)
FROM `schedule` s
JOIN scheduletemplatedetail sdt
ON s.TemplateId = sdt.TemplateId
WHERE s.ScheduleId = ScheduleId), DateOut = DateFrom
, RowNumber = 0;
SET TimeSheetDate = GetFirstDayOfMonth(DateFrom);
DROP TABLE IF EXISTS enumdays;
CREATE TEMPORARY TABLE enumdays (
DayOrder tinyint,
DateOut date,
TimeSheetDate date
);
WHILE (DateOut <= DateTo) DO
IF RowNumber = TemplateCount
THEN
SET RowNumber = 1;
ELSE
SET RowNumber := RowNumber + 1;
END IF;
INSERT INTO enumdays (DateOut
, DayOrder
, TimeSheetDate)
SELECT
DateOut,
RowNumber,
TimeSheetDate;
SET DateOut := DATE_ADD(DateOut, INTERVAL 1 DAY);
SET TimeSheetDate = GetFirstDayOfMonth(DateOut);
END WHILE;
DELETE
FROM s
USING scheduledetail s
WHERE s.ScheduleId = ScheduleId
AND s.DateOut BETWEEN DateFrom AND DateTo;
INSERT INTO scheduledetail (DateOut
, TimeSheetDate
, ScheduleId
, AbsenceCode)
SELECT
d.DateOut,
d.TimeSheetDate,
ScheduleId,
s.AbsenceCode
FROM enumdays d
CROSS JOIN (SELECT
s.TemplateId
FROM `schedule` s
WHERE s.ScheduleId = ScheduleId) s2
JOIN scheduletemplatedetail s
ON d.DayOrder = s.DayOrder
AND s.TemplateId = s2.TemplateId;
END
$$
Assume that you need to get Time Sheet for a specific time period. To do this, execute the FillSchedule procedure:
Click Procedures and then right-click the FillSchedule procedure, and click Execute on the shortcut menu.
Enter input parameters.
Suddenly we get the error message telling us that the TimeSheetDate column cannot be null.
Note
Actual document look may slightly vary from the above image, depending on the product you use.
A quick look through the code gives you nothing and you have no other choice but to start the debugger.
To start debugging the stored procedure:
If you have not compiled the procedure, Fusion for MySQL prompts you to compile it. Click Yes.
Enter the stored procedure input parameters once again and click OK.
You can see that the yellow arrow identifies the stack frame where the execution pointer is currently located.
Insert a breakpoint in the place where you insert the TimeSheetDate variable in the enumdays temporary table.
After several clicks you are hitting, this breakpoint which means that the current code isn’t ignored.
However, as you can see in the Watches window, the value of the TimeSheetDate variable is NULL. We know that the TimeSheetDate field cannot accept NULL values. So it can be concluded that the TimeSheetDate variable should be initialized.
Initialize the TimeSheetDate variable before inserting it into the table.
Now, once you hit the breakpoint, you can see that the value of the TimeSheetDate variable is the date, which is absolutely correct.
Click Retrieve Data on the shortcut menu.
Fusion for MySQL displays the result table.
As you see, the Debugger for MySQL is a very simple and powerful tool to use. You can use different debugging techniques to achieve successful results.