AlterQuery enum_nested_alter (children 2) ExpressionList (children 1) AlterCommand MODIFY_COLUMN (children 1) ColumnDeclaration n.e (children 1) DataType Array (children 1) ExpressionList (children 1) DataType Enum16 (children 1) ExpressionList (children 3) Function equals (children 1) ExpressionList (children 2) Literal \'Hello\' Literal UInt64_1 Function equals (children 1) ExpressionList (children 2) Literal \'World\' Literal UInt64_2 Function equals (children 1) ExpressionList (children 2) Literal \'a\' Literal UInt64_300 Identifier enum_nested_alter