insert returning id

[victrcodes]

Postgres has the "insert returning id" (http://www.postgresql.org/docs/9.4/static/sql-insert.html) functionality, is it possible to use this with existing functionality or is this something not yet implemented?

[sfackler]

Yep, it'll act like a normal query that returns a row set

let stmt = try!(conn.prepare("INSERT INTO foo (bar) VALUES ('baz') RETURNING id"));
let id: i32 = try!(stmt.query(&[])).iter().next().unwrap().get(0);

[victrcodes]

Thanks. I'm trying to do this with a transaction, is it possible? I'm currently getting an error

error: no method named `query` found for type `core::result::Result<postgres::Statement<'_>, postgres::error::Error>` in the current scope

let query = "INSERT INTO foo (bar) VALUES ('baz') RETURNING id";
let stmt = trans.prepare(query).unwrap();
let result = stmt.query(&[]);
let id: i32 = result.iter().next().unwrap().get(0);

UPDATE: Sorry, forgot the unwrap(), but getting a different error now:

error: no method named `get` found for type `&postgres::Rows<'_>` in the current scope
                    let id: i32 = result.iter().next().unwrap().get(0);

[sfackler]

query returns a Result as well, so you'll need to get the Rows out of it. Right now it's calling iter on the Result, not the Rows.

[victrcodes]

Got it, thanks, it's working.

[tylerhjones]

@sfackler could you help with an updated version of this?
Using version 0.17.0-alpha.1
I do not see a query method available on a Statement object

Would the following be a correct example?

    let stmt: Statement = conn.prepare(
        "INSERT INTO users \
        (usr_name, email, organization_id, role) \
        VALUES ($1, $2, $3, $4) \
        RETURNING id")?;

    let rows = conn.query(&stmt, &[&name, &usr_email, &org_id, &usr_role.role])?;

[sfackler]

Yes.