Question

我有empdetails表，其中列为分配的叶子。我还有一个用于LeavesTaken的专栏。现在，我要计算每个员工的请假余额并相应地进行更新。

        {
            command.Connection = _connection;
            SqlDataReader reader = command.ExecuteReader();
            Employee employee = new Employee();
            List<Users.LeaveRequest> leaves = new List<Users.LeaveRequest>();
            while (reader.Read())
            {
                leaves.Add(new Users.LeaveRequest() { DayPart = reader.GetInt32(3), fromdate = reader["fromdate"].ToString(), todate = reader["todate"].ToString() });
            }
            reader.Close();
            if (leaves.Count>0)
            {
                leaveRequests = leaves;
            }
            else
            {
                leaveRequests = null;
            }

            command.CommandText = "SELECT TotalLeaves,LeavesTaken FROM empDetails WHERE empID = @empid";
            //command.Parameters.AddWithValue("@empid", CurrentUser.Employee.EmpID);
            reader = command.ExecuteReader();
            if (reader.Read())
            {
                employee.TotalLeaves = reader.GetInt32(0);
                employee.LeavesTaken = reader.GetDouble(1);
            }
            reader.Close();
            return employee;
        }````

Answer 1

我可以想到三种解决方案，因为您没有精确指定所需的内容，也没有示例数据：

您想要总计员工的价值：

SELECT SUM(TotalLeaves), SUM(LeavesTaken)
FROM empDetails 
WHERE empID = @empid

您要在两个值之间取得平衡

SELECT SUM(TotalLeaves) - SUM(LeavesTaken)
FROM empDetails 
WHERE empID = @empid

如果每个empID有一条记录，您还可以尝试：

SELECT TotalLeaves - LeavesTaken
FROM empDetails 
WHERE empID = @empid

Answer 2

我很好奇为什么总叶子有整数，但是无论如何，您都可以在CommandText

中进行计算

假设这三列AllottedLeaves, TotalLeaves, LeavesTaken的数据类型为DECIMAL(4,2)

现在，我想计算每位员工的请假余额并相应地进行更新。

更新TABLE empDetails

中的所有员工

{
    command.CommandText = "UPDATE empDetails " + 
                          "SET TotalLeaves = TotalLeaves - llottedLeaves, " +
                          "LeavesTaken = LeavesTaken + AllottedLeaves, " +
                          "AllottedLeaves = 0" +
                          "WHERE AllottedLeaves <> 0 AND AllottedLeaves <= TotalLeaves";
    command.Connection = _connection;
    command.ExecuteNonQuery();
}

更新TABLE empDetails中的一名员工

{
    command.CommandText = "UPDATE empDetails " + 
                          "SET TotalLeaves = TotalLeaves - llottedLeaves, " +
                          "LeavesTaken = LeavesTaken + AllottedLeaves, " +
                          "AllottedLeaves = 0" +
                          "WHERE empID = @empid";
    command.Parameters.AddWithValue("@empid", CurrentUser.Employee.EmpID);
    command.Connection = _connection;
    command.ExecuteNonQuery();
}

如果我有每位员工的“总分配假”列，如何计算请假余额？

2 个答案: