https://github.com/Dowwie/tokio-postgres-mapper

Proc-macro library used to map a tokio-postgres row to a Rust type (struct)
https://github.com/Dowwie/tokio-postgres-mapper

Last synced: about 8 hours ago
JSON representation

Proc-macro library used to map a tokio-postgres row to a Rust type (struct)

• Host: GitHub
• URL: https://github.com/Dowwie/tokio-postgres-mapper
• Owner: Dowwie
• License: isc
• Created: 2020-01-10T12:05:20.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2022-07-20T21:01:59.000Z (over 2 years ago)
• Last Synced: 2024-11-11T22:22:50.525Z (5 days ago)
• Language: Rust
• Size: 46.9 KB
• Stars: 64
• Watchers: 5
• Forks: 18
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE.md

Awesome Lists containing this project

README

        
# tokio-pg-mapper

`tokio_postgres-mapper` is a proc-macro designed to make mapping from postgresql

tables to structs simple.

### Why?

It can be frustrating to write a lot of boilerplate and, ultimately, duplicated

code for mapping from postgres Rows into structs.

For example, this might be what someone would normally write:

```rust

extern crate postgres;

use postgres::rows::Row;

pub struct User {

    pub id: i64,

    pub name: String,

    pub email: Option,

}

impl From for User {

    fn from(row: Row) -> Self {

        Self {

            id: row.get("id"),

            name: row.get("name"),

            email: row.get("email"),

        }

    }

}

// code to execute a query here and get back a row

let user = User::from(row); // this can panic

```

This becomes worse when manually implementating using the non-panicking

`get_opt` method variant.

Using this crate, the boilerplate is removed, and panicking and non-panicking

implementations are derived:

```rust

extern crate tokio_pg_mapper_derive;

extern crate tokio_pg_mapper;

use tokio_pg_mapper::FromTokioPostgresRow;

use tokio_pg_mapper_derive::PostgresMapper;

#[derive(PostgresMapper)]

pub struct User {

    pub id: i64,

    pub name: String,

    pub email: Option,

}

// Code to execute a query here and get back a row might now look like:

let stmt = "SELECT * FROM user WHERE username = $1 AND password = $2";

let result = client.query_one(stmt, &[&5, "asdf"]).await?;

let user = User::from_row(result).unwrap(); // or from_row_ref(&result)

```

### The two crates

This repository contains two crates: `postgres-mapper` which contains an `Error`

enum and traits for converting from a `tokio-postgres` `Row`

without panicking, and `postgres-mapper-derive` which contains the proc-macro.

### Installation

Install `tokio-pg-mapper-derive` and `tokio-pg-mapper` from crates.io

### License

ISC.