SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.projections
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier database
     Function currentDatabase (children 1)
      ExpressionList
