表未更新。我使用相同的语法来更新其他表，但是这个表不起作用

Question

此sql查询未更新数据库，而是返回错误。有什么建议吗？

PreparedStatement ps10 = con.prepareStatement("UPDATE payroll_system.payslip SET hours_worked = (SELECT SUM(Hours) FROM payroll_system.monthly_timesheet WHERE employeeID=?) WHERE employeeID=?");
                    ps10.setString(1, employee_id);
                    ps10.setString(2, employee_id);
                    ps10.executeUpdate();

Answer 1

试试这个：

UPDATE payroll_system.payslip as t1 
    SET hours_worked = (SELECT SUM(Hours) FROM payroll_system.monthly_timesheet WHERE employeeID=t1.employeeID) 
    WHERE employeeID=?