title: Adding fake rows on a result of a query
body: <p>I have a table(T1) with the following columns: department,dateofsale,totalsales.
  What I want to achieve is to have the sales for department per month in one year from a start date and going backward 1 year.
  Maybe the following query will show better what I want to achieve.</p>
  
  <pre><code>-- Create the table T1
      CREATE TABLE [dbo].[T1](
      [department] [nvarchar](50) NULL,
      [dateofsale] [datetime] NULL,
      [totalsales] [decimal](18, 5) NULL
      ) ON [PRIMARY]
  
  -- Add some data 
      INSERT [dbo].[T1] ([department], [dateofsale], [totalsales]) VALUES (N'0001', CAST(0x0000A29B00000000 AS DateTime), CAST(200.00000 AS Decimal(18, 5)))
      INSERT [dbo].[T1] ([department], [dateofsale], [totalsales]) VALUES (N'0001', CAST(0x0000A27D00000000 AS DateTime), CAST(300.00000 AS Decimal(18, 5)))
      INSERT [dbo].[T1] ([department], [dateofsale], [totalsales]) VALUES (N'0001', CAST(0x0000A29C00000000 AS DateTime), CAST(200.00000 AS Decimal(18, 5)))
  
  -- The query
      declare @dataBegin datetime
      declare @dataEnd datetime
      set @dataEnd = '21/12/2013'
      set @dataBegin = DATEADD(month,-11, @dataEnd) - (DAY(@dataEnd)-1)
      set @dataEnd = DATEADD(month,1, @dataEnd) - (DAY(@dataEnd))
      SELECT department,SUM(totalsales) AS totsales, MONTH(dateofsale) as month, YEAR(dateofsale) as year
      FROM T1
      WHERE dateofsale &gt;= @dataBegin AND dateofsale&lt; @dataEnd 
      GROUP BY department,MONTH(dateofsale), YEAR(dateofsale)
      ORDER BY department,MONTH(dateofsale), YEAR(dateofsale)
  </code></pre>
  
  <p>With the data added before the result of the query will be the following:</p>
  
  <pre><code>    department  /totsales/  month /year
      0001/ 300.00000 /11 /2013
      0001/ 400.00000 /12 /2013
  </code></pre>
  
  <p>The problem is that I want also the months that has a value of zero as totalsales. So the result must be:</p>
  
  <blockquote>
  <pre><code>department    /totsales/  month /year
  0001/ 0   /1  /2013
  0001/ 0   /2  /2013
  0001/ 0   /3  /2013
  0001/ 0   /4  /2013
  0001/ 0   /5  /2013
  0001/ 0   /6  /2013
  0001/ 0   /7  /2013
  0001/ 0   /8  /2013
  0001/ 0   /9  /2013
  0001/ 0   /10 /2013
  0001/ 300.00000   /11 /2013
  0001/ 400.00000   /12 /2013
  </code></pre>
  </blockquote>
  
  <p>How can I do that?</p>