Trait diesel::deserialize::Queryable

pub trait Queryable<ST, DB> where
    DB: Backend, {
    type Row: FromSqlRow<ST, DB>;
    fn build(row: Self::Row) -> Self;
}

Trait indicating that a record can be queried from the database.

Types which implement Queryable represent the result of a SQL query. This does not necessarily mean they represent a single database table.

This trait can be derived automatically using #[derive(Queryable)]. This trait can only be derived for structs, not enums.

Diesel represents the return type of a query as a tuple. The purpose of this trait is to convert from a tuple of Rust values that have been deserialized into your struct.

When this trait is derived, it will assume that the order of fields on your struct match the order of the fields in the query. This means that field order is significant if you are using #[derive(Queryable)]. Field name has no affect.

Examples

If we just want to map a query to our struct, we can use derive.

#[derive(Queryable, PartialEq, Debug)]
struct User {
    id: i32,
    name: String,
}

let first_user = users.first(&connection)?;
let expected = User { id: 1, name: "Sean".into() };
assert_eq!(expected, first_user);

If we want to do additional work during deserialization, we can implement the trait ourselves.

use schema::users;
use diesel::deserialize::Queryable;

type DB = diesel::sqlite::Sqlite;

#[derive(PartialEq, Debug)]
struct User {
    id: i32,
    name: String,
}

impl Queryable<users::SqlType, DB> for User {
    type Row = (i32, String);

    fn build(row: Self::Row) -> Self {
        User {
            id: row.0,
            name: row.1.to_lowercase(),
        }
    }
}

let first_user = users.first(&connection)?;
let expected = User { id: 1, name: "sean".into() };
assert_eq!(expected, first_user);

Associated Types

type Row: FromSqlRow<ST, DB>

The Rust type you'd like to map from.

This is typically a tuple of all of your struct's fields.

Required Methods

fn build(row: Self::Row) -> Self

Construct an instance of this type

Implementations on Foreign Types

impl<T, ST> Queryable<Range<ST>, Pg> for (Bound<T>, Bound<T>) where
    T: FromSql<ST, Pg> + Queryable<ST, Pg>, 

type Row = Self

fn build(row: Self) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for Timespec where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for [u8; 6] where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for IpNetwork where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for Uuid where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for Value where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for SystemTime where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for NaiveDate where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for NaiveTime where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for NaiveDateTime where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<Tz: TimeZone, __ST, __DB> Queryable<__ST, __DB> for DateTime<Tz> where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<T, ST, DB> Queryable<Nullable<ST>, DB> for Option<T> where
    T: Queryable<ST, DB>,
    DB: Backend,
    Option<T::Row>: FromSqlRow<Nullable<ST>, DB>,
    ST: NotNull, 

type Row = Option<T::Row>

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for bool where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for i8 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for i16 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for i32 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for i64 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for u16 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for u32 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for u64 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for f32 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for f64 where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for String where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<T, __ST, __DB> Queryable<__ST, __DB> for Vec<T> where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<'a, T: ?Sized, ST, DB> Queryable<ST, DB> for Cow<'a, T> where
    T: 'a + ToOwned,
    DB: Backend,
    Self: FromSqlRow<ST, DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

impl<A, SA, __DB> Queryable<(SA,), __DB> for (A,) where
    __DB: Backend,
    A: Queryable<SA, __DB>, 

type Row = (A::Row,)

fn build(row: Self::Row) -> Self

impl<A, B, SA, SB, __DB> Queryable<(SA, SB), __DB> for (A, B) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>, 

type Row = (A::Row, B::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, SA, SB, SC, __DB> Queryable<(SA, SB, SC), __DB> for (A, B, C) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>, 

type Row = (A::Row, B::Row, C::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, SA, SB, SC, SD, __DB> Queryable<(SA, SB, SC, SD), __DB> for (A, B, C, D) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, SA, SB, SC, SD, SE, __DB> Queryable<(SA, SB, SC, SD, SE), __DB> for (A, B, C, D, E) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, SA, SB, SC, SD, SE, SF, __DB> Queryable<(SA, SB, SC, SD, SE, SF), __DB> for (A, B, C, D, E, F) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, SA, SB, SC, SD, SE, SF, SG, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG), __DB> for (A, B, C, D, E, F, G) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, SA, SB, SC, SD, SE, SF, SG, SH, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH), __DB> for (A, B, C, D, E, F, G, H) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, SA, SB, SC, SD, SE, SF, SG, SH, SI, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI), __DB> for (A, B, C, D, E, F, G, H, I) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ), __DB> for (A, B, C, D, E, F, G, H, I, J) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK), __DB> for (A, B, C, D, E, F, G, H, I, J, K) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, L, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL), __DB> for (A, B, C, D, E, F, G, H, I, J, K, L) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>,
    L: Queryable<SL, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row, L::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM), __DB> for (A, B, C, D, E, F, G, H, I, J, K, L, M) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>,
    L: Queryable<SL, __DB>,
    M: Queryable<SM, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row, L::Row, M::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN), __DB> for (A, B, C, D, E, F, G, H, I, J, K, L, M, N) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>,
    L: Queryable<SL, __DB>,
    M: Queryable<SM, __DB>,
    N: Queryable<SN, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row, L::Row, M::Row, N::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN, SO, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN, SO), __DB> for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>,
    L: Queryable<SL, __DB>,
    M: Queryable<SM, __DB>,
    N: Queryable<SN, __DB>,
    O: Queryable<SO, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row, L::Row, M::Row, N::Row, O::Row)

fn build(row: Self::Row) -> Self

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN, SO, SP, __DB> Queryable<(SA, SB, SC, SD, SE, SF, SG, SH, SI, SJ, SK, SL, SM, SN, SO, SP), __DB> for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P) where
    __DB: Backend,
    A: Queryable<SA, __DB>,
    B: Queryable<SB, __DB>,
    C: Queryable<SC, __DB>,
    D: Queryable<SD, __DB>,
    E: Queryable<SE, __DB>,
    F: Queryable<SF, __DB>,
    G: Queryable<SG, __DB>,
    H: Queryable<SH, __DB>,
    I: Queryable<SI, __DB>,
    J: Queryable<SJ, __DB>,
    K: Queryable<SK, __DB>,
    L: Queryable<SL, __DB>,
    M: Queryable<SM, __DB>,
    N: Queryable<SN, __DB>,
    O: Queryable<SO, __DB>,
    P: Queryable<SP, __DB>, 

type Row = (A::Row, B::Row, C::Row, D::Row, E::Row, F::Row, G::Row, H::Row, I::Row, J::Row, K::Row, L::Row, M::Row, N::Row, O::Row, P::Row)

fn build(row: Self::Row) -> Self

impl<__ST, __DB> Queryable<__ST, __DB> for BigDecimal where
    __DB: Backend,
    Self: FromSql<__ST, __DB>, 

type Row = Self

fn build(row: Self::Row) -> Self

Implementors

• impl<__ST, __DB> Queryable<__ST, __DB> for PgTimestamp where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl<__ST, __DB> Queryable<__ST, __DB> for PgDate where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl<__ST, __DB> Queryable<__ST, __DB> for PgTime where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl<__ST, __DB> Queryable<__ST, __DB> for PgInterval where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl<__ST, __DB> Queryable<__ST, __DB> for PgNumeric where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl<__ST, __DB> Queryable<__ST, __DB> for PgMoney where
    __DB: Backend,
    Self: FromSql<__ST, __DB>,  type Row = Self;
• impl Queryable<(Oid, Oid), Pg> for PgTypeMetadata type Row = (u32, u32);