Struct Query

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

Representation of a database query. See QueryOpsSync and QueryOpsAsync for operations requiring a live database connection.

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)

Trait Implementations

impl<T> Clone for Query<T>

where T: DataResult,

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

Returns a duplicate 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.

impl<T> QueryOpsAsync<T> for Query<T>

where T: DataResult,

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

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

async fn load(self, conn: &impl ConnectionMethodsAsync) -> Result<Vec<T>, Error>

Executes the query against conn.

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

Executes the query against conn and deletes all matching objects.

impl<T> QueryOpsSync<T> for Query<T>

where T: DataResult,

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

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

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

Executes the query against conn.

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

Executes the query against conn and deletes all matching objects.