# one This table contains a single row with a single `dummy` UInt8 column containing the value 0. This table is used if a `SELECT` query does not specify the `FROM` clause. This is similar to the `DUAL` table found in other DBMSs. **Example** ```sql :) SELECT * FROM system.one LIMIT 10; ``` ```text ┌─dummy─┐ │ 0 │ └───────┘ 1 rows in set. Elapsed: 0.001 sec. ``` [Original article](https://clickhouse.com/docs/en/operations/system-tables/one)