Struct Column

pub struct Column<'t, S, T>(/* private fields */);

Values of this type reference a collumn in a query.

• The lifetime parameter 't specifies in which query the collumn exists.
• The type parameter S specifies the expected schema of the query.
• And finally the type paramter T specifies the type of the column.

Column implements Deref to have table extension methods in case the type is a table type.

Implementations

impl<'t, S, T: NumTyp> Column<'t, S, T>

pub fn add(&self, rhs: impl IntoColumn<'t, S, Typ = T>) -> Column<'t, S, T>

Add two columns together.

pub fn lt(&self, rhs: impl IntoColumn<'t, S, Typ = T>) -> Column<'t, S, bool>

Compute the less than operator of two columns.

impl<'t, S, T: EqTyp + 't> Column<'t, S, T>

pub fn eq(&self, rhs: impl IntoColumn<'t, S, Typ = T>) -> Column<'t, S, bool>

Check whether two columns are equal.

impl<'t, S> Column<'t, S, bool>

pub fn not(&self) -> Column<'t, S, bool>

Checks whether a column is false.

pub fn and( &self, rhs: impl IntoColumn<'t, S, Typ = bool>, ) -> Column<'t, S, bool>

Check if two columns are both true.

pub fn or(&self, rhs: impl IntoColumn<'t, S, Typ = bool>) -> Column<'t, S, bool>

Check if one of two columns is true.

impl<'t, S, Typ: 't> Column<'t, S, Option<Typ>>

pub fn unwrap_or( &self, rhs: impl IntoColumn<'t, S, Typ = Typ>, ) -> Column<'t, S, Typ>

where Self: IntoColumn<'t, S, Typ = Option<Typ>>,

Use the first column if it is Some, otherwise use the second column.

pub fn is_some(&self) -> Column<'t, S, bool>

Check that the column is Some.

impl<'t, S> Column<'t, S, i64>

pub fn as_float(&self) -> Column<'t, S, f64>

Convert the i64 column to f64 type.

Trait Implementations

impl<'t, S, T> Clone for Column<'t, S, T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'t, S, T: Table> Deref for Column<'t, S, T>

type Target = <T as Table>::Ext<Column<'t, S, T>>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'t, S: 't, T: 't> IntoColumn<'t, S> for Column<'t, S, T>

fn into_column(self) -> Column<'t, S, Self::Typ>

Turn this value into a Column.