CreateQuery destination (children 3)
 Identifier destination
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration some_data (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType JSON
   ColumnDeclaration a_val (children 2)
    DataType String
    Function arrayElement (children 1)
     ExpressionList (children 2)
      Identifier some_data.a
      Literal UInt64_1
 Storage definition (children 2)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList
