create table with schema inferenced from data

Question

In clickhouse version 22.1 it is possible to inference schema. e.g.: DESC file('nonexist', 'Protobuf') SETTINGS format_schema='file.proto:LogEntry'

But is it possible to create table with columns obtained from DESCRIBE?

Answer 1

yes

cat /var/lib/clickhouse/user_files/aa.csv
a, b, 4

create table t1 Engine=Log  as select * from file('aa.csv');

DESCRIBE TABLE  t1
┌─name─┬─type──────────────┬─default_type─┬─default_expression─┬─comment─┬─codec_expression─┬─ttl_expression─┐
│ c1   │ Nullable(String)  │              │                    │         │                  │                │
│ c2   │ Nullable(String)  │              │                    │         │                  │                │
│ c3   │ Nullable(Float64) │              │                    │         │                  │                │
└──────┴───────────────────┴──────────────┴────────────────────┴─────────┴──────────────────┴────────────────┘


create table t1 Engine=Log  as select * from file('aa.csv') where 0;
DESCRIBE TABLE  t1
┌─name─┬─type──────────────┬─default_type─┬─default_expression─┬─comment─┬─codec_expression─┬─ttl_expression─┐
│ c1   │ Nullable(String)  │              │                    │         │                  │                │
│ c2   │ Nullable(String)  │              │                    │         │                  │                │
│ c3   │ Nullable(Float64) │              │                    │         │                  │                │
└──────┴───────────────────┴──────────────┴────────────────────┴─────────┴──────────────────┴────────────────┘