title: invoke-sqlcmd empty variable
body: <p>I am trying to perform an SQL query using <code>Invoke-SqlCmd</code> launching script as inputfile which contains SQLCMD variables, as $(varPROJECTNAME).</p>
  
  <p>For example:
  <code>CREATE DATABASE [$(varPROJECTNAME)$(varDBNAME)]</code>
  In such a case, i want to be able to set an empty string as <code>varPROJECTNAME</code> value.</p>
  
  <p>This request will run successfully with classical SQLCMD tool, but with Invoke-SqlCmd, i get error, script variable varPROJECTNAME is undefined.</p>
  
  <pre><code>Invoke-Sqlcmd  -Username $LoginSQL -Password $PasswordSQL -ServerInstance $InstanceSQL -Verbose  -InputFile "$rootPackage\DB\UpdateDB\00-initSql\00-SubsTechCreateDatabase.sql"  -Variable "varPROJECTNAME=$projectName","varDBNAME=$DatabaseName"
  </code></pre>
  
  <p>In case above, if   <code>$projectName=""</code>, There will be an error</p>
  
  <p>Is it possible to set a default value calling Invoke-SqlCmd, or from sql script point of view, assign a default value to the variable when it's undefined?</p>
  
  <p>Many thanks in advance for your help</p>