Struct Selector 

pub struct Selector<M> { /* private fields */ }

A SELECT decoded into an arbitrary FromQueryResult type.

Implementations

impl<M: FromQueryResult> Selector<M>

pub fn from_query(query: Select) -> Self

Wraps any SQL select.

pub fn from_statement(statement: Statement) -> RawSelector<M>

Wraps a raw statement.

pub fn build(&self) -> Statement

Renders the statement.

pub async fn one<C: ConnectionTrait>(self, db: &C) -> Result<Option<M>>

Fetches the first row, adding LIMIT 1.

Errors

Returns DbErr::Driver when the query fails or the row cannot be decoded.

pub async fn all<C: ConnectionTrait>(self, db: &C) -> Result<Vec<M>>

Fetches every row.

Errors

Returns DbErr::Driver when the query fails or a row cannot be decoded.

pub async fn stream<'a, C: StreamTrait>( self, db: &'a C, ) -> Result<ModelStream<'a, M>>

where M: 'a,

Streams rows as they are read.

Errors

Returns DbErr::Driver when the query cannot be started; decoding failures surface as items of the stream.

pub async fn count<C: ConnectionTrait>(self, db: &C) -> Result<u64>

Counts the rows with SELECT COUNT(*) FROM (query).

Ordering, limit and offset are stripped from the inner query because they do not affect the total and would only slow the count down.

Errors

Returns DbErr::RecordNotFound when the count query returns no row; DbErr::Driver when the query fails.

pub async fn exists<C: ConnectionTrait>(self, db: &C) -> Result<bool>

Whether the query returns at least one row, through SELECT EXISTS (query).

Errors

Returns DbErr::RecordNotFound when the probe returns no row; DbErr::Driver when the query fails.

pub fn paginate<C: ConnectionTrait>( self, db: &C, page_size: u64, ) -> Paginator<'_, C, M>

Paginates with page_size rows per page; a page size of zero is treated as one.

Trait Implementations

impl<M: Clone> Clone for Selector<M>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<M: Debug> Debug for Selector<M>

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

Formats the value using the given formatter.