Trait AssignColumn 

pub trait AssignColumn: Sized {
    type Assignment;

    const TYPE: ColumnType;

    // Required method
    fn assignment(
        self,
        field_value: FieldValue,
    ) -> Result<Self::Assignment, ValueMismatch>;
}

A Diesel column a model’s merge-patch writes can set: one whose SQL type converts a domain value (ColumnValue).

Blanket-implemented over assignment.

Required Associated Constants

const TYPE: ColumnType

What the column takes, for the compile-time check that a domain field’s value fits it (ColumnValue::TYPE).

Required Associated Types

type Assignment

The assignment column = value.

Required Methods

fn assignment( self, field_value: FieldValue, ) -> Result<Self::Assignment, ValueMismatch>

See assignment.

Errors

See assignment.

Dyn Compatibility

This trait is not dyn compatible.

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

Implementors

impl<C> AssignColumn for C

where C: Expression + ExpressionMethods, C::SqlType: SqlType + TypedExpressionType + ColumnValue, ValueOf<C>: AsExpression<C::SqlType>,

Available on crate feature merge-patch only.

const TYPE: ColumnType = <C::SqlType as ColumnValue>::TYPE

type Assignment = Grouped<Eq<C, <<<C as Expression>::SqlType as ColumnValue>::Rust as AsExpression<<C as Expression>::SqlType>>::Expression>>