Trait diesel::row::Row

pub trait Row<'a, DB: Backend>: RowIndex<usize> + for<'b> RowIndex<&'b str> + RowSealed + Sized {
    type Field<'f>: Field<'f, DB>
       where Self: 'f,
             'a: 'f;
    type InnerPartialRow: Row<'a, DB>;

    // Required methods
    fn field_count(&self) -> usize;
    fn get<'b, I>(&'b self, idx: I) -> Option<Self::Field<'b>>
       where Self: RowIndex<I>,
             'a: 'b;
    fn partial_row(
        &self,
        range: Range<usize>
    ) -> PartialRow<'_, Self::InnerPartialRow>;

    // Provided method
    fn get_value<ST, T, I>(&self, idx: I) -> Result<T>
       where Self: RowIndex<I>,
             T: FromSql<ST, DB> { ... }
}

Represents a single database row.

This trait is used as an argument to FromSqlRow.

Required Associated Types

type Field<'f>: Field<'f, DB> where Self: 'f, 'a: 'f

Field type returned by a Row implementation

• Crates using existing backends should not concern themself with the concrete type of this associated type.

• Crates implementing custom backends should provide their own type meeting the required trait bounds

type InnerPartialRow: Row<'a, DB>

Return type of PartialRow

For all implementations, beside of the Row implementation on PartialRow itself this should be Self.

Required Methods

fn field_count(&self) -> usize

Get the number of fields in the current row

fn get<'b, I>(&'b self, idx: I) -> Option<Self::Field<'b>>

where Self: RowIndex<I>, 'a: 'b,

Get the field with the provided index from the row.

Returns None if there is no matching field for the given index

fn partial_row( &self, range: Range<usize> ) -> PartialRow<'_, Self::InnerPartialRow>

Returns a wrapping row that allows only to access fields, where the index is part of the provided range.

Provided Methods

fn get_value<ST, T, I>(&self, idx: I) -> Result<T>

where Self: RowIndex<I>, T: FromSql<ST, DB>,

Get a deserialized value with the provided index from the row.

Object Safety

This trait is not object safe.

Implementors

impl<'a, 'b, DB, R> Row<'a, DB> for PartialRow<'b, R>

where DB: Backend, R: Row<'a, DB>,

type Field<'f> = <R as Row<'a, DB>>::Field<'f> where R: 'f, Self: 'f, 'a: 'f

type InnerPartialRow = R