[−][src]Crate tokio_pg_mapper
tokio-postgres-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:
use postgres::row::Row; pub struct User { pub id: i64, pub name: String, pub email: Option<String>, } impl From<Row> 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:
#[macro_use] extern crate tokio_pg_mapper_derive; use tokio_pg_mapper; use tokio_pg_mapper::FromPostgresRow; #[derive(PostgresMapper)] pub struct User { pub id: i64, pub name: String, pub email: Option<String>, } // code to execute a query here and get back a row // `tokio_pg_mapper::FromPostgresRow`'s methods do not panic and return a Result let user = User::from(row)?;
The two crates
This repository contains two crates: postgres-mapper
which contains an Error
enum and traits for converting from a postgres
or tokio-postgres
Row
without panicking, and postgres-mapper-derive
which contains the proc-macro.
postgres-mapper-derive
has 3 features that can be enabled (where T is the
struct being derived with the provided PostgresMapper
proc-macro):
impl From<::tokio_postgres::row::Row> for T
and
impl From<&::tokio_postgres::row::Row> for T
implementations
postgres-mapper
which, for each of the above features, implementspostgres-mapper
'sFromPostgresRow
and/orFromTokioPostgresRow
traits
This will derive implementations for converting from owned and referenced
tokio-postgres::row::Row
s, as well as implementing postgres-mapper
's
FromTokioPostgresRow
trait for non-panicking conversions.
Enums
Error | General error type returned throughout the library. |
Traits
FromTokioPostgresRow | Trait containing various methods for converting from a |