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POCount entries across three tables based on month in SQL or LINQ
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2010-02-24T15:45:34.247
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2010-02-25T07:36:45.970
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2010-02-24T22:13:03.157
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I would like to extract some data from three tables in a SQL Server 2005 database. While this can surely be done in code, it seems like this could be done reasonably well in SQL (bonus points for LINQ!). Basically, I would like to know for each month how many calls and meetings each employee has held with each of our clients. Something like this: <pre><code>Employee GUID Customer GUID Jan calls Jan mtgs Feb calls Feb mtgs... [a guid] [another guid] 5 0 7 3 </code></pre> The data is spread across three tables. For simplicity's sake, let's just show the relevant columns: Communications Table <pre><code>[CommunicationId] (PK, uniqueidentifier) [Type] (nvarchar(1)) ('C' for call, 'M' for meeting, etc.) [Date] (datetime) </code></pre> Person-Communication Table <pre><code>[PersonId] (PK, FK, uniqueidentifier) (Can contain GUIDs for employees or clients, see Person Table below) [CommunicationId] (PK, FK, uniqueidentifier) </code></pre> Person Table <pre><code>[PersonId] (PK, uniqueidentifier) [Type] (nvarchar(1)) ('E' for employee, 'C' for customer) </code></pre> So, the questions: <ol> <li>Can this be done in SQL without horrendous code or big performance problems?</li> <li>If so, how? I'd even settle for a good high-level strategy. I'm guessing <a href="http://msdn.microsoft.com/en-us/library/ms177410.aspx" rel="nofollow noreferrer">pivots</a> will play a big role here (particularly the "Complex PIVOT Example"). <a href="http://msdn.microsoft.com/en-us/library/ms174420.aspx" rel="nofollow noreferrer">DATEPART(MONTH, Date)</a> seems like a good method for partitioning the communications by month along the lines of:</li> </ol> <blockquote> <pre><code>SELECT DATEPART(MONTH, Date), COUNT(*) FROM [CommunicationTable] WHERE DATEPART(YEAR, Date) = '2009' GROUP BY DATEPART(MONTH, Date) ORDER BY DATEPART(MONTH, Date) </code></pre> </blockquote> ... which gets me the number of communications in each month in 2009: <pre><code>1 2871 2 2639 3 3654 4 2751 5 1773 6 2575 7 2906 8 2398 9 2621 10 2638 11 1705 12 2290 </code></pre>
Tags
<sql><sql-server><sql-server-2005><pivot><pivot-table>
Title
Count entries across three tables based on month in SQL or LINQ
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1. PO
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1. This table or related slice is empty.
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1. PTQuestion
UserLastEditorUserId
1. USKevin L.
UserOwnerUserId
1. USKevin L.
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1. PO
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 POCount entries across three tables based on month in SQL or LINQ
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