Crate clickhouse_rs

clickhouse-rs

Tokio based asynchronous Yandex ClickHouse client library for rust programming language.

Installation

Library hosted on crates.io.

[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)
• IPv4/IPv6
• UUID

DNS

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

parameters:

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

  • none
  • lz4

• readonly - Restricts permissions for read data, write data and change settings queries. (defaults to none). Possible choices:

  • 0 - All queries are allowed.
  • 1 - Only read data queries are allowed.
  • 2 - Read data and change settings queries are allowed.

• 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).

• alt_hosts - Comma separated list of single address host for load-balancing.

• query_timeout - Timeout for queries (defaults to 180 sec).

• query_block_timeout - Timeout for each block in a query (defaults to 180 sec).

• insert_timeout - Timeout for inserts (defaults to 180 sec).

• execute_timeout - Timeout for execute (defaults to 180 sec).

SSL/TLS parameters:

• secure - establish secure connection (defaults is false).
• skip_verify - skip certificate verification (defaults is false).

example:

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

Example

use futures::Future;
use clickhouse_rs::{Pool, types::Block};

 let ddl = "
     CREATE TABLE IF NOT EXISTS payment (
         customer_id  UInt32,
         amount       UInt32,
         account_name 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 done = pool
    .get_handle()
    .and_then(move |c| c.execute(ddl))
    .and_then(move |c| c.insert("payment", block))
    .and_then(move |c| c.query("SELECT * FROM payment").fetch_all())
    .and_then(move |(_, block)| {
        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(())
    })
    .map_err(|err| eprintln!("database error: {}", err));

tokio::run(done)

Re-exports

pub use crate::pool::Pool;

Modules

errors

Error types.

pool

Pool types.

types

Clickhouse types.

Macros

row

This macro is a convenient way to pass row into a block.

Structs

ClientHandle

Clickhouse client handle.