Varint | ScyllaDB Docs

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 which is a very simple wrapper representing the value as signed binary number in big-endian order.

Example¶

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?
    .into_typed::<(BigInt,)>();
while let Some((varint_value,)) = iter.try_next().await? {
    println!("{:?}", varint_value);
}

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