How do I use the JSON type?

[jakejscott]

I have the following code:

Cargo.toml file has this in it:

[package]
name = "postgres-queue"
version = "0.0.1"

[dependencies]
postgres = "0.8.4"
rustc-serialize = "0.3"

extern crate rustc_serialize as serialize;
extern crate postgres;

use serialize::json;
use postgres::*;


#[derive(Debug)]
struct Job {
    id: i32,
    name: String,
    json: json::Json,
    state: i32,
}

fn main() {
    let conninfo = "postgres://postgres:[email protected]/queuedb";
    let conn = Connection::connect(conninfo, &SslMode::None).unwrap();

    let stmt = conn.prepare("SELECT id, name, json, state FROM job LIMIT 10").unwrap();
    let rows = stmt.query(&[]).unwrap();

    for row in rows {

        let job = Job {
            id: row.get(0),
            name: row.get(1),
            json: row.get(2),
            state: row.get(3),
        };

        println!("Job: {:?}", job);
    }
}

When I compile I get the following error

jakescott@rustbox:~/rust/postgres-queue$ cargo run
   Compiling postgres-queue v0.0.1 (file:///home/jakescott/rust/postgres-queue)
src/main.rs:28:14: 28:20 error: the trait `postgres::types::FromSql` is not implemented for the type `rustc_serialize::json::Json` [E0277]
src/main.rs:28          json: row.get(2),
                                  ^~~~~~
error: aborting due to previous error
Could not compile `postgres-queue`.

To learn more, run the command again with --verbose.
jakescott@rustbox:~/rust/postgres-queue$ 

[jakejscott]

After digging around for a while I found out about rust features.
http://doc.crates.io/manifest.html#the-[features]-section

So I needed to change my Cargo.toml file to:

[package]
name = "postgres-queue"
version = "0.0.1"

[features]
default = ["postgres"]

[dependencies]
rustc-serialize = "*"

[dependencies.postgres]
version = "*"
features = ["uuid", "rustc-serialize", "time"]
optional = true

Leaving this here in case someone else get's tripped up by this. And yes I should RTFM!

[vayn]

@superlogical This error is hard to solve. Thank you for saving my day!