SQL query for calculating mtd, ytd values

Question

I have a table with columns ID, Title, Date, Amount.

I need to get MTD, YTD amount values against each transaction based on Title, Date.

Is there anyone who had done this before?

Answer 1

Select t.title, t.Date, 
  Sum(y.Amount) YTD,
  Sum(m.Amount) MTD
From table t
   left join table y
      on y.Title = t.Title
         and datediff(year, y.Date, t.Date) = 0 
         and y.Date <= t.Date
  left join table m
      on m.Title = t.Title
         and datediff(month, m.Date, t.Date) = 0 
         and m.Date <= t.Date
         and m.Date <> y.Date
Group by t.title, t.Date

Answer 2

The accepted solution is incorrect. Let's say we have a following table:

ID   Title   Date        Amount
---  ------  ----------  ------
  1  Cust A  2020-01-01    2.00
  2  Cust A  2020-01-05    3.00
  3  Cust A  2020-02-01    5.00

The accepted answer would give us these results:

Title   Date        YTD    MTD
------  ----------  -----  -----
Cust A  2021-01-01   2.00   2.00
Cust A  2021-01-05  10.00  10.00
Cust A  2021-02-01  10.00  15.00

This is due to the fact that each join multiplies the number of records by the number of matching records. This can be easily seen when the aggregation is removed:

Select t.title, t.Date, y.Date, m.Date,
  y.Amount,
  m.Amount
From [table] t
   join [table] y
      on y.Title = t.Title
         and datediff(year, y.Date, t.Date) = 0 
         and y.Date <= t.Date
   join [table] m
      on m.Title = t.Title
         and datediff(month, m.Date, t.Date) = 0 
         and m.Date <= t.Date
Order by t.title, t.Date, y.Date, m.Date

Results:

Title   t.Date      y.Date      m.Date      y.Amount    m.Amount
-----   ----------  ----------  ----------  --------    --------
Cust A  2021-01-01  2021-01-01  2021-01-01         2           2
Cust A  2021-01-05  2021-01-01  2021-01-01         2           2
Cust A  2021-01-05  2021-01-01  2021-01-05         2           3
Cust A  2021-01-05  2021-01-05  2021-01-01         3           2
Cust A  2021-01-05  2021-01-05  2021-01-05         3           3
Cust A  2021-02-01  2021-01-01  2021-02-01         2           5
Cust A  2021-02-01  2021-01-05  2021-02-01         3           5
Cust A  2021-02-01  2021-02-01  2021-02-01         5           5

Here is a modified select that produces correct results:

Select a.title, a.Date, 
  Sum(Case When datediff(year, b.Date, a.Date) = 0 Then b.Amount Else 0 End) YTD,
  Sum(Case When datediff(month, b.Date, a.Date) = 0 Then b.Amount Else 0 End) MTD
From [table] a
   join [table] b
      on a.Title = b.Title
         and b.Date <= a.Date
Group by a.title, a.Date

Results:

Title   Date        YTD    MTD
------  ----------  -----  -----
Cust A  2021-01-01   2.00   2.00
Cust A  2021-01-05   5.00   5.00
Cust A  2021-02-01  10.00   5.00

Here is a SQL Fiddle with all the current answers plus new solutions.