title: SQL Server check resultant data type of expression
body: <p>Normally I would put the data type into a temp table and inspect the table column type, e.g.</p>
  
  <pre><code>select 1.0 N into tbl
  
  sp_help tbl
  </code></pre>
  
  <p>Column N then reveals the data type of the expression <code>1.0</code>.  (This is a only simple example)</p>
  
  <p>There is a SQL function to inspect the data type of an expression directly, but the name escapes me right now.</p>
  
  <p>What is the name of this function?</p>