Tokio ClickHouse Client

Asynchronous Yandex ClickHouse client library for rust programming language.

Installation

Library hosted on crates.io. toml [dependencies] clickhouse-rs = "*"

Supported data types

• Date
• DateTime
• Decimal(P, S)
• Float32, Float64
• String, FixedString(N)
• UInt8, UInt16, UInt32, UInt64, Int8, Int16, Int32, Int64
• Nullable(T)
• Array(UInt/Int/String/Date/DateTime)

DNS

url schema://user:password@host[:port]/database?param1=value1&...&paramN=valueN

parameters:

• compression - Whether or not use compression (defaults to none). Possible choices:

  • none
  • lz4

• connection_timeout - Timeout for connection (defaults to 500 ms)

• keepalive - TCP keep alive timeout in milliseconds.

• nodelay - Whether to enable TCP_NODELAY (defaults to true).

• pool_max - Lower bound of opened connections for Pool (defaults to 10).

• pool_min - Upper bound of opened connections for Pool (defaults to 20).

• ping_before_query - Ping server every time before execute any query. (defaults to true).

• send_retries - Count of retry to send request to server. (defaults to 3).
• retry_timeout - Amount of time to wait before next retry. (defaults to 5 sec).
• ping_timeout - Timeout for ping (defaults to 500 ms).

example: url tcp://user:password@host:9000/clicks?compression=lz4&ping_timeout=42ms

Optional features

clickhouse-rs puts some functionality behind optional features to optimize compile time for the most common use cases. The following features are available.

• tokio_io (enabled by default) — I/O based on Tokio.
• async_std — I/O based on async-std (doesn't work together with tokio_io).
• tls — TLS support (allowed only with tokio_io).

Example

```rust use clickhouse_rs::{Block, Pool}; use std::error::Error;

[tokio::main]

async fn main() -> Result<(), Box> { let ddl = r" CREATE TABLE IF NOT EXISTS payment ( customerid UInt32, amount UInt32, accountname Nullable(FixedString(3)) ) Engine=Memory";

let block = Block::new()
    .column("customer_id",  vec![1_u32,  3,  5,  7,  9])
    .column("amount",       vec![2_u32,  4,  6,  8, 10])
    .column("account_name", vec![Some("foo"), None, None, None, Some("bar")]);

let pool = Pool::new(database_url);

let mut client = pool.get_handle().await?;
client.execute(ddl).await?;
client.insert("payment", block).await?;
let block = client.query("SELECT * FROM payment").fetch_all().await?;

for row in block.rows() {
    let id: u32             = row.get("customer_id")?;
    let amount: u32         = row.get("amount")?;
    let name: Option<&str>  = row.get("account_name")?;
    println!("Found payment {}: {} {:?}", id, amount, name);
}

Ok(())

} ```