drop table if exists defaulted; create table defaulted (col1 default 0) engine=Memory; desc table defaulted; drop table defaulted; create table defaulted (col1 UInt32, col2 default col1 + 1, col3 materialized col1 + 2, col4 alias col1 + 3) engine=Memory; desc table defaulted; insert into defaulted (col1) values (10); select * from defaulted; select col3, col4 from defaulted; drop table defaulted; create table defaulted (col1 Int8, col2 UInt64 default (SELECT dummy+99 from system.one)) engine=Memory; --{serverError THERE_IS_NO_DEFAULT_VALUE} set allow_deprecated_syntax_for_merge_tree=1; create table defaulted (payload String, date materialized today(), key materialized 0 * rand()) engine=MergeTree(date, key, 8192); desc table defaulted; insert into defaulted (payload) values ('hello clickhouse'); select * from defaulted; alter table defaulted add column payload_length UInt64 materialized length(payload); desc table defaulted; select *, payload_length from defaulted; insert into defaulted (payload) values ('some string'); select *, payload_length from defaulted order by payload; select *, payload_length from defaulted order by payload; alter table defaulted modify column payload_length default length(payload); desc table defaulted; select * from defaulted order by payload; alter table defaulted modify column payload_length default length(payload) % 65535; desc table defaulted; select * from defaulted order by payload; alter table defaulted modify column payload_length UInt16 default length(payload); desc table defaulted; alter table defaulted drop column payload_length; desc table defaulted; select * from defaulted order by payload; drop table defaulted;