ClickHouse/docs/en/operations/system-tables/one.md
2022-08-28 09:58:27 -04:00

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---
slug: /en/operations/system-tables/one
---
# 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) <!--hide-->