# ch2rs

**Repository Path**: mirrors_ClickHouse/ch2rs

## Basic Information

- **Project Name**: ch2rs
- **Description**: Generate Rust structs from ClickHouse rows
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-07-30
- **Last Updated**: 2026-02-28

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# ch2rs

An auxiliary utility for generating Rust structures from ClickHouse DB schemas for the official [clickhouse-rs](https://github.com/ClickHouse/clickhouse-rs) crate.

## Usage

```sh
cargo install ch2rs
```

The crate enables `rustls-tls` [client](https://github.com/ClickHouse/clickhouse-rs/blob/main/Cargo.toml) feature by default, which allows to work with HTTPS URLs. 
If `rustls-tls` does not work in your use case, you can install the crate with `native-tls` instead:

```sh
cargo install ch2rs --features native-tls
```

### Help

```sh
$ ch2rs --help
```

```
ch2rs 0.1.7

USAGE:
    ch2rs [FLAGS] [OPTIONS] <table>

FLAGS:
    -D               Generate `Deserialize` instances
    -h, --help       Prints help information
        --owned      Generate only owned types
    -S               Generate `Serialize` instances
    -V, --version    Prints version information

OPTIONS:
    -B <bytes>...              Add `#[serde(with = "serde_bytes")]` to the provided column
    -d <database>              A database where the table is placed in [default: default]
    -I <ignore>...             Ignore a specified column
    -O <overrides>...          Override the type of the provided column
    -p <password>
        --derive <trait>...    Add `#[derive(<trait>)]` to the generated types
    -T <types>...              Override the type, e.g. 'Decimal(18, 9)=fixnum::FixedPoint<i64, typenum::U9>'
    -U <url>                   ClickHouse server's URL [default: localhost:8123]
    --temporal <mode>          Temporal mapping: raw|time|chrono [default: raw]
    -u <user>

ARGS:
    <table>    The table's name
```

### Temporal modes

- **raw** (default): uses primitive Rust types:
  - Date → `u16`, Date32 → `i32`
  - DateTime → `u32`, DateTime64(_) → `i64`
  - Time → `i32`, Time64(_) → `i64`

- **time**: uses the `time` crate types
  - Date/Date32: `time::Date`
  - DateTime/DateTime64: `time::OffsetDateTime`
  - Time/Time64: `time::Duration`
  - Requires in your project: `time` dependency and `clickhouse` feature `time`
    - `clickhouse = { version = "…", features = ["time"] }`

- **chrono**: uses the `chrono` crate types
  - Date/Date32: `chrono::NaiveDate`
  - DateTime/DateTime64: `chrono::DateTime<chrono::Utc>`
  - Time/Time64: `chrono::Duration`
  - Requires in your project: `chrono` dependency and `clickhouse` feature `chrono`
    - `clickhouse = { version = "…", features = ["chrono"] }`

Select mode via `--temporal {raw|time|chrono}`.

## Examples

See [snapshots](tests/snapshots).