MySQL使用游标触发并循环更新错误值

Question

Hey im having problems setting the correct value in an update statement inside a loop triggered by an update on another table.

I have 2 tables, employees and base_wage. The base wage is what new employees will receive as standard for their job position. In the employees table there is a salary column which typically is the base wage, but can sometimes be higher than the base wage. For instance if a guy has been in a position for many years he might get a higher salary compared to a guy that just got the job.

I have made a trigger AFTER UPDATE ON the base_wage table which sets the new base wage for every employee with that position. The trigger should also take into account the extra salary that some employees might have and add that to their salary ontop of the new base wage.

The trigger works, but it doesn't add the extra salary to those employees that gets more than the base wage.

I have created a Fiddle here: http://sqlfiddle.com/#!2/cfe116/1

In the fiddle the base wage for a manager is 150, and i have added two managers to the employees table, one with a salary of 150 (the base) and one that gets 170 (20 more than base). If i now want to change the base wage for managers to 160, the first manager should get 160 as salary and the second one should get his salary (170) minus the old base wage (150) plus the new base wage = 180. Right now both managers salary changes to 160 for some odd reason.

So any idea why this doesn't work? Am i missing something here?

Thanks in advance :)

Answer 1

Problem is here UPDATE employees SET salary = mTotalSalary WHERE jobTitel = OLD.position;

You are updating the employee table using the position and it will update each employee having the same position with the same value you will need to use the employeeid into consideration.

First declare

declare empId INT;

Then fetch the employee id into the cursor

SELECT salary,employeeId FROM employees WHERE jobTitel = OLD.position;

And use it in the declared variable

FETCH employeeCursor INTO mSalary,empId;

Finally change the update command as

UPDATE employees SET salary = mTotalSalary WHERE employeeId = empId;

Here is the fiddle http://sqlfiddle.com/#!2/b4840/1