title: Need efficient way to perform database update from excel file for survey manager
body: <p>I have a tree with respondent-unit structure. Where respondents belong to units. 
  Lets assume that there are two departments in Bank, so I will have:</p>
  
  <pre><code>  + Accountants
       - Homer Simpson
       - Bart Simpson
       - Leny
    + It department 
       - Charles Bartowski
       - Sarah Walker
       - Bill
  </code></pre>
  
  <p>Where accountans and IT are departments, and respondents inside them.
  Each <code>respondent</code> has general properties:</p>
  
  <pre><code> - Email
   - Language
   - Name
   - DepartmentID
  </code></pre>
  
  <p>Each department can provide it's own dynamic properties for all his respondents:</p>
  
  <pre><code> - Salary
   - Respondent age
   - Gender
  </code></pre>
  
  <p>This properties can be added and deleted in runtime. They are stored as tables</p>
  
  <p>Properties:</p>
  
  <pre><code>- Property name
  - Property ID
  </code></pre>
  
  <p>Property values:</p>
  
  <pre><code> - PropertyValueID
   - PropertyID
   - Value
  </code></pre>
  
  <p>I need to perform possibility to export them in <code>Excel</code> file, then user can edit smth in this excel and when he uploaded it to server, database should be updated.</p>
  
  <p>I did export in Excel. 
  Now I am looking for good approach to perform allow upload. 
  Are there any articles or patterns for that to do it in efficient way?</p>
  
  <p>Thanks in advance)</p>
  
  <p>I am using ASP.NET and EPPlus for working with Excel.</p>