Struct butane::query::Query

pub struct Query<T>where
    T: DataResult,{ /* private fields */ }

Representation of a database query.

Implementations

impl<T> Query<T>where T: DataResult,

pub fn new(table: &'static str) -> Query<T>

Creates a query which matches all objects in table. The set of matched objects can be restricted with filter and limit.

pub fn filter(self, expr: BoolExpr) -> Query<T>

Restricts the query to matching only objects for which expr is true. Returns self as this method is expected to be chained.

pub fn limit(self, lim: i32) -> Query<T>

Limits the query to matching the first lim objects. Returns self as this method is expected to be chained.

pub fn offset(self, off: i32) -> Query<T>

Skips the first off objects before returning them. Returns self as this method is expected to be chained.

pub fn order(self, column: &'static str, direction: OrderDirection) -> Query<T>

Order the query results by the given column. Multiple calls to this method may be made, with earlier calls taking precedence. It is recommended to use the colname! macro to construct the column name in a type-safe manner.

pub fn order_asc(self, column: &'static str) -> Query<T>

Shorthand for order(column, OrderDirection::Ascending)

pub fn order_desc(self, column: &'static str) -> Query<T>

Shorthand for order(column, OrderDirection::Descending)

pub fn load_first( self, conn: &impl ConnectionMethods ) -> Result<Option<T>, Error>

Executes the query against conn and returns the first result (if any).

pub fn load( self, conn: &impl ConnectionMethods ) -> Result<Vec<T, Global>, Error>

Executes the query against conn.

pub fn delete(self, conn: &impl ConnectionMethods) -> Result<usize, Error>

Executes the query against conn and deletes all matching objects.

Trait Implementations

impl<T> Clone for Query<T>where T: Clone + DataResult,

fn clone(&self) -> Query<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Query<T>where T: Debug + DataResult,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.