varint.md

Varint

Varint is represented as value::CqlVarint or num_bigint::BigInt.

num_bigint::BigInt

To make use of num_bigint::BigInt type, user should enable one of the available feature flags (num-bigint-03 or num-bigint-04). They enable support for num_bigint::BigInt v0.3 and v0.4 accordingly.

value::CqlVarint

Without any feature flags, the user can interact with Varint type by making use of value::CqlVarint or value::CqlVarintBorrowed which are very simple wrappers representing the value as signed binary number in big-endian order.

Example

# extern crate scylla;
# extern crate num_bigint;
# extern crate futures;
# use scylla::Session;
# use std::error::Error;
# async fn check_only_compiles(session: &Session) -> Result<(), Box<dyn Error>> {
use futures::TryStreamExt;
use num_bigint::BigInt;
use std::str::FromStr;

// Insert a varint into the table
let to_insert: BigInt = BigInt::from_str("12345")?;
session
    .query_unpaged("INSERT INTO keyspace.table (a) VALUES(?)", (to_insert,))
    .await?;

// Read a varint from the table
let mut iter = session.query_iter("SELECT a FROM keyspace.table", &[])
    .await?
    .rows_stream::<(BigInt,)>()?;
while let Some((varint_value,)) = iter.try_next().await? {
    println!("{:?}", varint_value);
}
# Ok(())
# }