title: SQL: datetime or varchar as parameter datatype for stored procedure
body: <p>I have a SQL server stored procedure which would accept date as input param to build a query in it.So which datatype i should use for the parameter when defining stored procedure.Whats the difference between using nvarchar(15) and datetime .</p>
  
  <pre><code>1 : create procedure TestProcedure(@startDate datetime)
          and
  2 :   create procedure TestProcedure(@startDate nvarchar(15))
  </code></pre>
  
  <p>IS there any advantage is i use datetime over varchar in terms of performance</p>