Cannot get out a Connection and Transaction from inside of fn. Is by design of SQLX? or i missing something?.

[sirlordt]

I try the next code work. But i don't known is sqlx design that not work or i missing something.

I need a function can return both the DBConnection and DBTransaction, the transaction started in the body of the function.

use std::cell::RefCell;
use std::rc::Rc;

use sqlx::{pool::PoolConnection, Acquire, Error, MySql, Pool, Transaction};

type DBConn = Rc<RefCell<sqlx::pool::PoolConnection<MySql>>>;
type DBTrans<'t> = Rc<RefCell<sqlx::Transaction<'t, MySql>>>;

// This work!!!. But is only the connection
async fn connection_mysql<'c>(connection_pool: Option<&'c Pool<MySql>>) -> Result<DBConn, Error> {
    match connection_pool {
        Some(connection_pool) => {

            let conn: PoolConnection<MySql> = match connection_pool.acquire().await {
                Ok(conn) => conn,
                Err(error) => return Err(error),
            };

            let rc_conn: Rc<RefCell<PoolConnection<MySql>>> = Rc::new( RefCell::new( conn ) );

            Ok(rc_conn)

        }
        None => {
            Err(Error::PoolClosed)
        }
    }
}

//Not work. I Need the connection and the transaction
async fn begin_transaction_mysql<'c>(connection_pool: Option<&'c Pool<MySql>>) -> Result<(DBConn,DBTrans), Error> {
    match connection_pool {
        Some(connection_pool) => {

            let conn: PoolConnection<MySql> = match connection_pool.acquire().await {
                Ok(conn) => conn,
                Err(error) => return Err(error),
            };

            let rc_conn: Rc<RefCell<PoolConnection<MySql>>> = Rc::new( RefCell::new( conn ) );

            let rc_conn_cloned = rc_conn.clone();

            let trans_onwed: Transaction<'c, MySql> = Rc::try_unwrap( rc_conn_cloned ).ok().unwrap().into_inner().begin().await.unwrap();

            let rc_trans: Rc<RefCell<Transaction<'c, MySql>>> = Rc::new( RefCell::new( trans_onwed ) );

            //let rc_trans: Rc<RefCell<Transaction<'_, MySql>>> = Rc::new( RefCell::new( rc_conn_cloned.borrow_mut().begin().await.unwrap()) );

            //let rc_trans_cloned = rc_trans.clone();

            Ok((rc_conn, rc_trans))

        }
        None => {
            Err(Error::PoolClosed)
        }
    }
}

   Compiling sqlx_mysql_tokio_01 v0.1.0 (/home/dsystems01/Desktop/rust-lang/projects/test/sqlx_mysql_tokio_01)
error[E0716]: temporary value dropped while borrowed
   --> src/main.rs:358:55
    |
345 | async fn begin_transaction_mysql<'c>(connection_pool: Option<&'c Pool<MySql>>) -> Result<(DBConn,DBTrans), Error> {
    |                                  -- lifetime `'c` defined here
...
358 |             let trans_onwed: Transaction<'c, MySql> = Rc::try_unwrap( rc_conn_cloned ).ok().unwrap().into_inner().begin().await.unwrap();
    |                              ----------------------   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                       - temporary value is freed at the end of this statement
    |                              |                        |
    |                              |                        creates a temporary value which is freed while still in use
    |                              type annotation requires that borrow lasts for `'c`

For more information about this error, try `rustc --explain E0716`.
error: could not compile `sqlx_mysql_tokio_01` (bin "sqlx_mysql_tokio_01") due to 1 previous error

I changed the code to include temp. But still not work

//Not work. I Need the connection and the transaction
async fn begin_transaction_mysql<'c>(connection_pool: Option<&'c Pool<MySql>>) -> Result<(DBConn,DBTrans), Error> {
    match connection_pool {
        Some(connection_pool) => {

            let conn: PoolConnection<MySql> = match connection_pool.acquire().await {
                Ok(conn) => conn,
                Err(error) => return Err(error),
            };

            let rc_conn: Rc<RefCell<PoolConnection<MySql>>> = Rc::new( RefCell::new( conn ) );

            let rc_conn_cloned = rc_conn.clone();

            let temp = &mut Rc::try_unwrap( rc_conn_cloned ).ok().unwrap().into_inner();

            let trans_onwed: Transaction<'c, MySql> = temp.begin().await.unwrap();

            let rc_trans: Rc<RefCell<Transaction<'c, MySql>>> = Rc::new( RefCell::new( trans_onwed ) );

            //let rc_trans: Rc<RefCell<Transaction<'_, MySql>>> = Rc::new( RefCell::new( rc_conn_cloned.borrow_mut().begin().await.unwrap()) );

            //let rc_trans_cloned = rc_trans.clone();

            Ok((rc_conn, rc_trans))

        }
        None => {
            Err(Error::PoolClosed)
        }
    }
}

   Compiling sqlx_mysql_tokio_01 v0.1.0 (/home/dsystems01/Desktop/rust-lang/projects/test/sqlx_mysql_tokio_01)
error[E0716]: temporary value dropped while borrowed
   --> src/main.rs:358:29
    |
345 | async fn begin_transaction_mysql<'c>(connection_pool: Option<&'c Pool<MySql>>) -> Result<(DBConn,DBTrans), Error> {
    |                                  -- lifetime `'c` defined here
...
358 |             let temp = &mut Rc::try_unwrap( rc_conn_cloned ).ok().unwrap().into_inner();
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
359 |
360 |             let trans_onwed: Transaction<'c, MySql> = temp.begin().await.unwrap();
    |                              ---------------------- type annotation requires that borrow lasts for `'c`
...
370 |         }
    |         - temporary value is freed at the end of this statement

For more information about this error, try `rustc --explain E0716`.
error: could not compile `sqlx_mysql_tokio_01` (bin "sqlx_mysql_tokio_01") due to 1 previous error

[frederikhors]

@sirlordt did you find a way?