Crate sqlm_postgres

An sql! macro to write compile-time checked database queries similar to how format! works.

Example

use sqlm_postgres::{sql, Enum, FromRow, FromSql, ToSql};

let id: i64 = 1;
let user: User = sql!("SELECT * FROM users WHERE id = {id}").await?;

#[derive(Debug, FromRow)]
struct User {
    id: i64,
    name: String,
    role: Role,
}

#[derive(Debug, Default, FromSql, ToSql, Enum)]
#[postgres(name = "role")]
enum Role {
    #[default]
    #[postgres(name = "user")]
    User,
    #[postgres(name = "admin")]
    Admin,
}

Usage

• Add sqlm-postgres to your dependencies
• Make the DATABASE_URL env variable available during compile time (e.g. via adding an .env file)
• Start using the sql! macro (no further setup necessary; a connection pool is automatically created for you)

Caveats

• Automatically creates a global connection pool for you with no way to opt out
• Compile-time checks cannot be disabled. Thus also requires database access on your CI.
• Does not know whether rows returned from Postgres are nullable and consequentially requires all types to implement Default::default, which it falls back to if Postgres returns null.

Re-exports

• pub use tokio_postgres;

Macros

• sql
  Creates a parameterized, compile-time checked database query that accepts parameters similar to the format! macro.

Structs

• Error
  An error communicating with the Postgres server.
• Row
  A row of data returned from Postgres.
• Sql
  The struct created by sql!; executed by calling .await.
• SqlFuture
  A future for executing an sql query.

Traits

• Connection
  A trait used to allow functions to accept connections without having to explicit about whether it’s a transaction or not.
• FromRow
  A trait for types that can be created from a Row (a postgres row containing columns as constraint by Cols).
• FromSql
  A trait for types that can be created from a Postgres value.
• SqlType
  A trait used to which Rust type a Postgres type is read into.
• ToSql
  A trait for types that can be converted into Postgres values.

Functions

• connect
  Establish a database connection.

Type Aliases

• Client
  An asynchronous PostgreSQL client (basically a non-transactional connection).
• Transaction
  A database transaction.

Derive Macros

• Enum
  A derive necessary to support compile checks between Postgres and Rust enums.
• FromRow
  Derive FromRow for a struct, required read a query result into a struct.