title: how to include hard-coded value to output from mysql query?
body: <p>I've created a <strong>MySQL sproc</strong> which returns 3 separate result sets.  I'm implementing the npm mysql package downstream to exec the sproc and get a result structured in json with the 3 result sets.  I need the ability to filter the json result sets that are returned based on some type of indicator in each result set.  For example, if I wanted to get the result set from the json response which deals specifically with Suppliers then I could use some type of js filter similar to this:</p>
  
  <pre><code>var supplierResultSet = mySqlJsonResults.filter(x =&gt; x.ResultType === 'SupplierResults');
  </code></pre>
  
  <p>I think SQL Server provides the ability to include a hard-coded column value in a SQL result set like this:</p>
  
  <pre><code>select
  'SupplierResults',
  *
  from
  supplier
  </code></pre>
  
  <p>However, this approach appears to be invalid in MySQL b/c MySQL Workbench is telling me that the sproc syntax is invalid and won't let me save the changes.  Do you know if something like what I'm trying to achieve is possible in MySQL and if not then can you recommend alternative approaches that would help me achieve my ultimate goal of including some type of fixed indicator in each result set to provide a handle for downstream filtering of the json response?</p>