Trait IntoSelect 

pub trait IntoSelect<'columns, S>: Sized {
    type Out: 'static;

    // Required method
    fn into_select(self) -> Select<'columns, S, Self::Out>;
}

This trait is implemented by everything that can be retrieved from the database.

Making a selection of values to return for each row in the result set is the final step when building queries. rust_query has many different methods of selecting.

• First, you can specify the columns that you want directly. into_vec(&user.name) or into_vec((&user.name, some_other_expr)) Note that this method only supports tuples of size 2 (which can be nested). If you want to have more expressions, then you probably want to use one of the other methods.
• Derive crate::Select, super useful when some of the values are aggregates.
• Derive crate::FromExpr, choose this method if you just want (a subset of) existing columns.
• Finally, you can implement IntoSelect manually, for maximum flexibility.

Note that you can often easily solve ownership issues by adding a reference. So for example instead of into_vec((user, &user.name)), you should use into_vec((&user, &user.name)).

Required Associated Types

type Out: 'static

The type that results from executing the Select.

Required Methods

fn into_select(self) -> Select<'columns, S, Self::Out>

This method is what tells rust-query how to turn the value into a Select.

The only way to implement this method is by constructing a different value that implements IntoSelect and then calling the IntoSelect::into_select method on that other value. The result can then be modified with Select::map.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<'columns, S, A, B> IntoSelect<'columns, S> for (A, B)

where A: IntoSelect<'columns, S>, B: IntoSelect<'columns, S>,

type Out = (<A as IntoSelect<'columns, S>>::Out, <B as IntoSelect<'columns, S>>::Out)

fn into_select(self) -> Select<'columns, S, Self::Out>

impl<'columns, S, T> IntoSelect<'columns, S> for &T

where T: IntoSelect<'columns, S> + Clone,

type Out = <T as IntoSelect<'columns, S>>::Out

fn into_select(self) -> Select<'columns, S, Self::Out>

impl<'columns, S> IntoSelect<'columns, S> for ()

type Out = ()

fn into_select(self) -> Select<'columns, S, Self::Out>

Implementors

impl<'columns, S, Out: 'static> IntoSelect<'columns, S> for Select<'columns, S, Out>

type Out = Out

impl<'columns, S, T> IntoSelect<'columns, S> for Expr<'columns, S, T>

where T: DbTyp,

type Out = T