title: Check Varchar Value is Numeric without overflow
body: <p>I have a table with <code>PostalCode</code> Column that type's is <code>Char(10)</code>, I use the following Select query:</p>
  
  <pre><code>SELECT [Fm].[Id], [Sdp].[FirstName], [Sdp].[LastName], [Sdp].[SSN],
  [Sdp].[StoreName],
  case when isnumeric([Sdp].[PostalCode]) = 1 then CONVERT(CHAR(10),[Sdp].[PostalCode]) 
  else '0' end,  [Fc].[Id], [Sdp].[Address]
  
  FROM [SRM].[SiteMembers].[DProfile] AS [Sdp]
  INNER JOIN [SRM].[SiteMembers].[Member] AS [Sm]
  ON [Sdp].[Member_Id] = [Sm].[Id]
  INNER JOIN [FRM].[Members].[Member] AS [Fm]
  ON [Sm].[UserId] = [Fm].[UserId]
  INNER JOIN [SRM].[General].[City] AS [Sc]
  ON [Sdp].[City_Id]=[Sc].[Id]
  INNER JOIN [FRM].[General].[City] AS [Fc]
  ON [Fc].[Title]=[Sc].[Title] 
  COLLATE SQL_Latin1_General_CP1_CI_AS
  </code></pre>
  
  <p>Whit this script the Over flow error raised like this: </p>
  
  <pre><code>Msg 248, Level 16, State 1, Line 2
  The conversion of the varchar value '4153675759' overflowed an int column.
  </code></pre>
  
  <p>I ask a question <a href="https://stackoverflow.com/questions/9373964/merge-two-sql-script-use-if-condition-in-select-query/9374130#9374130">here</a> and I don't want back to past with 2 scripts, So is there any way to check the PostalCode is numeric (and I mean numeric not int) without any error?</p>