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.

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

pub fn starts_with(&self, pattern: impl AsRef<str>) -> Column<'t, S, bool>

Check if the column starts with the string pattern.

Matches case-sensitive. The pattern gets automatically escaped.

pub fn ends_with(&self, pattern: impl AsRef<str>) -> Column<'t, S, bool>

Check if the column ends with the string pattern.

Matches case-sensitive. The pattern gets automatically escaped.

pub fn contains(&self, pattern: impl AsRef<str>) -> Column<'t, S, bool>

Check if the column contains the string pattern.

Matches case-sensitive. The pattern gets automatically escaped.

pub fn like( &self, pattern: impl Into<String> + Clone + 't, ) -> Column<'t, S, bool>

Check if the column matches the pattern docs.

As noted in the docs, it is case-insensitive for ASCII characters. Other characters are case-sensitive. For creating patterns it uses % as a wildcard for any sequence of characters and _ for any single character. Special characters should be escaped with \.

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

Check if the column matches the pattern docs.

This is a case-sensitive version of like. It uses Unix file globbing syntax for wild cards. * matches any sequence of characters and ? matches any single character. [0-9] matches any single digit and [a-z] matches any single lowercase letter. ^ negates the pattern.

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.