serde-sqlx

Allows deserializing Postgres rows into Rust types using serde. Work in progress.

Implementation Status

Completed ✅

• Simple Primitives:

  • Strings: TEXT, VARCHAR, BPCHAR
  • Booleans
  • Integers: i16, i32, i64 (INT2, INT4, INT8/BIGINT)
  • Floating point: f32 (REAL), f64 (DOUBLE PRECISION)
  • Support for special float values (NaN, Infinity)

• Structs and Tuples:

  • Deserialize into named structs with primitive fields
  • Support for tuple structs and anonymous tuples
  • Deep nesting of structs using Serde's flattening

• Optional Values:

  • NULL values into Option

• JSON and JSONB:

  • Directly deserialize JSON data into Rust structures

• Newtypes:

  • Support for newtype pattern (e.g., struct UserId(i32))

• PostgreSQL Arrays:

  • Convert Postgres arrays into Rust vectors
  • Support for arrays of primitive types and nullable types

Planned/untested 📝

• Enums:
  • Support for Rust enums with Postgres enums or discriminated JSON
• Timestamps and Dates:
  • Testing for chrono and time types
• UUID:
  • Testing for uuid crate types

Usage

Add serde-sqlx to your Cargo.toml:

[dependencies]
serde-sqlx = "0.1"
serde = { version = "1", features = ["derive"] }
sqlx = { version = "0.6", features = ["postgres", "runtime-tokio-native-tls"] }

Basic example:

use serde::Deserialize;

#[derive(Deserialize, Debug)]
struct User {
    id: i32,
    name: String,
    active: bool,
    profile: Option<Profile>,
}

#[derive(Deserialize, Debug)]
struct Profile {
    bio: String,
    age: i32,
}

async fn get_users(pool: &PgPool) -> anyhow::Result<Vec<User>> {
    let rows = sqlx::query(
        "SELECT id, name, active, profile::JSONB FROM users"
    ).fetch_all(pool).await?;

    let users: Result<Vec<_>, _> = rows.into_iter()
        .map(serde_sqlx::from_pg_row)
        .collect();

    users.map_err(Into::into)
}