title: Transact-SQL / Check if a name already exists
body: <p>Simple question here.</p>
  
  <p><strong>Context:</strong> A Transact-SQL table with an int primary key, and a name that also must be unqiue (even though it's not a primary key). Let's say:</p>
  
  <pre><code>TableID INT,
  TableName NVARCHAR(50)
  </code></pre>
  
  <p>I'm adding a new rows to this able through a stored procedure (and, thus, specifying TableName with a parameter).</p>
  
  <p><strong>Question:</strong> What's the best/simplest way to verify if the provided TableName parameter already exist in the table, and to prevent the add of a new row if it's the case?</p>
  
  <p>Is possible to do this directly within my AddNewRow stored procedure?</p>