CreateQuery enum_nested_alter (children 3) Identifier enum_nested_alter Columns definition (children 1) ExpressionList (children 3) ColumnDeclaration d (children 2) DataType Date Literal \'2000-01-01\' ColumnDeclaration x (children 1) DataType UInt64 ColumnDeclaration n (children 1) DataType Nested (children 1) ExpressionList (children 3) NameTypePair a (children 1) DataType String NameTypePair e (children 1) DataType Enum8 (children 1) ExpressionList (children 1) Function equals (children 1) ExpressionList (children 2) Literal \'Hello.world\' Literal UInt64_1 NameTypePair b (children 1) DataType UInt8 Storage definition (children 1) Function MergeTree (children 1) ExpressionList (children 3) Identifier d Identifier x Literal UInt64_1