Trait diesel::expression::AsExpression
source · pub trait AsExpression<T>where
T: SqlType + TypedExpressionType,{
type Expression: Expression<SqlType = T>;
// Required method
fn as_expression(self) -> Self::Expression;
}Expand description
Converts a type to its representation for use in Diesel’s query builder.
This trait is used directly. Apps should typically use IntoSql instead.
Implementations of this trait will generally do one of 3 things:
-
Return
selffor types which are already parts of Diesel’s query builder -
Perform some implicit coercion (for example, allowing
nowto be used as bothTimestampandTimestamptz. -
Indicate that the type has data which will be sent separately from the query. This is generally referred as a “bind parameter”. Types which implement
ToSqlwill generally implementAsExpressionthis way.
This trait could be derived
Required Associated Types§
sourcetype Expression: Expression<SqlType = T>
type Expression: Expression<SqlType = T>
The expression being returned
Required Methods§
sourcefn as_expression(self) -> Self::Expression
fn as_expression(self) -> Self::Expression
Perform the conversion