title: Union can't be translated to SQL
body: <p>I'm using EFCore 2.2.3 and I have disabled local evaluation.</p>
  
  <p>I have the following queries</p>
  
  <pre><code>var query1 = companyContext.Companies.Where(c =&gt; c.Name == name);
  var query2 = companyContext.Companies.Where(c =&gt; c.Id == 10);
  </code></pre>
  
  <p>If i execute them on their own they work correctly.</p>
  
  <pre><code>await query1.ToListAsync();
  await query2.ToListAsync();
  </code></pre>
  
  <p>But if i try to</p>
  
  <pre><code>var result = await query1.Union(query2).ToListAsync();
  </code></pre>
  
  <p>i get the following error:</p>
  
  <blockquote>
    <p>InvalidOperationException: Error generated for warning
    'Microsoft.EntityFrameworkCore.Query.QueryClientEvaluationWarning: The
    LINQ expression 'Union({from Company c in
    value(Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1[MagliteTest.Database.Company])
    where ([c].Id == 10) select [c]})' could not be translated and will be
    evaluated locally.'. This exception can be suppressed or logged by
    passing event ID 'RelationalEventId.QueryClientEvaluationWarning' to
    the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or
    'AddDbContext'.</p>
  </blockquote>
  
  <p>Is union not supported on entity framework core?</p>