Struct Alias

#[non_exhaustive]
pub struct Alias<S> {
    pub source: S,
}

Represents an alias within diesel’s query builder

See alias! for more details.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

source: S

The inner alias definition

Implementations

impl<S: AliasSource> Alias<S>

pub fn field<F>(&self, field: F) -> AliasedField<S, F>

where F: Column<Table = S::Target>,

Maps a single field of the source table in this alias

pub fn fields<Fields>(&self, fields: Fields) -> AliasedFields<S, Fields>

where Fields: FieldAliasMapper<S>,

Maps multiple fields of the source table in this alias (takes in tuples and some expressions)

Trait Implementations

impl<S, QS> AppearsInFromClause<QS> for Alias<S>

where S: AliasSource, S::Target: AliasAppearsInFromClause<S, QS>,

type Count = <<S as AliasSource>::Target as AliasAppearsInFromClause<S, QS>>::Count

How many times does Self appear in QS?

impl<S> AsQuery for Alias<S>

where S: AliasSource, S::Target: AsQuery, Self: QuerySource, <Self as QuerySource>::DefaultSelection: ValidGrouping<()>,

type SqlType = <<Alias<S> as QuerySource>::DefaultSelection as Expression>::SqlType

The SQL type of Self::Query

type Query = SelectStatement<FromClause<Alias<S>>>

What kind of query does this type represent?

fn as_query(self) -> Self::Query

Converts a type which semantically represents a SQL query into the actual query being executed. See the trait level docs for more.

impl<'a, S, DB> BoxedDsl<'a, DB> for Alias<S>

where Alias<S>: QuerySource + AsQuery<Query = SelectStatement<FromClause<Alias<S>>>>, SelectStatement<FromClause<Alias<S>>>: BoxedDsl<'a, DB>, <Alias<S> as QuerySource>::DefaultSelection: Expression<SqlType = <Alias<S> as AsQuery>::SqlType> + ValidGrouping<()>, <Alias<S> as AsQuery>::SqlType: TypedExpressionType,

type Output = <SelectStatement<FromClause<Alias<S>>> as BoxedDsl<'a, DB>>::Output

The return type of internal_into_boxed

fn internal_into_boxed(self) -> Self::Output

See the trait documentation.

impl<S: Clone> Clone for Alias<S>

fn clone(&self) -> Alias<S>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<S> CombineDsl for Alias<S>

where S: AliasSource, S::Target: Table, Self: AsQuery,

type Query = <Alias<S> as AsQuery>::Query

What kind of query does this type represent?

fn union<Rhs>(self, rhs: Rhs) -> Union<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL UNION

fn union_all<Rhs>(self, rhs: Rhs) -> UnionAll<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL UNION ALL

fn intersect<Rhs>(self, rhs: Rhs) -> Intersect<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL INTERSECT

fn intersect_all<Rhs>(self, rhs: Rhs) -> IntersectAll<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL INTERSECT ALL

fn except<Rhs>(self, rhs: Rhs) -> Except<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL EXCEPT

fn except_all<Rhs>(self, rhs: Rhs) -> ExceptAll<Self, Rhs>

where Rhs: AsQuery<SqlType = <<Self as AsQuery>::Query as Query>::SqlType>,

Combine two queries using a SQL EXCEPT ALL

impl<S: Debug> Debug for Alias<S>

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

Formats the value using the given formatter.

impl<S: Default> Default for Alias<S>

fn default() -> Alias<S>

Returns the “default value” for a type.

impl<S, Selection> DistinctOnDsl<Selection> for Alias<S>

where S: AliasSource, Selection: SelectableExpression<Self>, Self: QuerySource + AsQuery<Query = SelectStatement<FromClause<Self>>>, SelectStatement<FromClause<Self>>: DistinctOnDsl<Selection>, <Self as QuerySource>::DefaultSelection: Expression<SqlType = <Self as AsQuery>::SqlType> + ValidGrouping<()>, <Self as AsQuery>::SqlType: TypedExpressionType,

Available on crate feature postgres_backend only.

type Output = <SelectStatement<FromClause<Alias<S>>> as DistinctOnDsl<Selection>>::Output

The type returned by .distinct_on

fn distinct_on(self, selection: Selection) -> DistinctOn<Self, Selection>

See the trait documentation

impl<S, Predicate> FilterDsl<Predicate> for Alias<S>

where Self: AsQuery, <Self as AsQuery>::Query: FilterDsl<Predicate>,

type Output = <<Alias<S> as AsQuery>::Query as FilterDsl<Predicate>>::Output

The type returned by .filter.

fn filter(self, predicate: Predicate) -> Self::Output

See the trait documentation.

impl<S, PK> FindDsl<PK> for Alias<S>

where S: AliasSource, S::Target: Table, <S::Target as Table>::PrimaryKey: FieldAliasMapper<S>, <<S::Target as Table>::PrimaryKey as FieldAliasMapper<S>>::Out: EqAll<PK>, Self: FilterDsl<<<<S::Target as Table>::PrimaryKey as FieldAliasMapper<S>>::Out as EqAll<PK>>::Output>,

type Output = <Alias<S> as FilterDsl<<<<<S as AliasSource>::Target as Table>::PrimaryKey as FieldAliasMapper<S>>::Out as EqAll<PK>>::Output>>::Output

The type returned by .find.

fn find(self, id: PK) -> Self::Output

See the trait documentation.

impl<S, Expr> GroupByDsl<Expr> for Alias<S>

where Expr: Expression, Self: QuerySource + AsQuery<Query = SelectStatement<FromClause<Self>>>, <Self as QuerySource>::DefaultSelection: Expression<SqlType = <Self as AsQuery>::SqlType> + ValidGrouping<()>, <Self as AsQuery>::SqlType: TypedExpressionType, <Self as AsQuery>::Query: GroupByDsl<Expr>,

type Output = <SelectStatement<FromClause<Alias<S>>> as GroupByDsl<Expr>>::Output

The type returned by .group_by

fn group_by(self, expr: Expr) -> GroupBy<Self, Expr>

See the trait documentation.

impl<S> LimitDsl for Alias<S>

where Self: AsQuery, <Self as AsQuery>::Query: LimitDsl,

type Output = <<Alias<S> as AsQuery>::Query as LimitDsl>::Output

The type returned by .limit

fn limit(self, limit: i64) -> Self::Output

See the trait documentation

impl<S, Lock> LockingDsl<Lock> for Alias<S>

where Self: QuerySource + AsQuery<Query = SelectStatement<FromClause<Self>>>, <Self as QuerySource>::DefaultSelection: Expression<SqlType = <Self as AsQuery>::SqlType> + ValidGrouping<()>, <Self as AsQuery>::SqlType: TypedExpressionType,

type Output = <SelectStatement<FromClause<Alias<S>>> as LockingDsl<Lock>>::Output

The type returned by set_lock. See dsl::ForUpdate and friends for convenient access to this type.

fn with_lock(self, lock: Lock) -> Self::Output

See the trait level documentation

impl<S> OffsetDsl for Alias<S>

where Self: AsQuery, <Self as AsQuery>::Query: OffsetDsl,

type Output = <<Alias<S> as AsQuery>::Query as OffsetDsl>::Output

The type returned by .offset.

fn offset(self, offset: i64) -> Self::Output

See the trait documentation

impl<S, Predicate> OrFilterDsl<Predicate> for Alias<S>

where Self: AsQuery, <Self as AsQuery>::Query: OrFilterDsl<Predicate>,

type Output = <<Alias<S> as AsQuery>::Query as OrFilterDsl<Predicate>>::Output

The type returned by .filter.

fn or_filter(self, predicate: Predicate) -> Self::Output

See the trait documentation.

impl<S, Expr> OrderDsl<Expr> for Alias<S>

where Expr: Expression, Self: AsQuery, <Self as AsQuery>::Query: OrderDsl<Expr>,

type Output = <<Alias<S> as AsQuery>::Query as OrderDsl<Expr>>::Output

The type returned by .order.

fn order(self, expr: Expr) -> Self::Output

See the trait documentation.

impl<S: AliasSource> QueryDsl for Alias<S>

fn distinct_on<Expr>(self, expr: Expr) -> DistinctOn<Self, Expr>

where Self: DistinctOnDsl<Expr>,

Available on crate feature postgres_backend only.

Adds the DISTINCT ON clause to a query.

fn select<Selection>(self, selection: Selection) -> Select<Self, Selection>

where Selection: Expression, Self: SelectDsl<Selection>,

Adds a SELECT clause to the query.

fn count(self) -> Select<Self, CountStar>

where Self: SelectDsl<CountStar>,

Get the count of a query. This is equivalent to .select(count_star())

fn inner_join<Rhs>(self, rhs: Rhs) -> InnerJoin<Self, Rhs>

where Self: JoinWithImplicitOnClause<Rhs, Inner>,

Join two tables using a SQL INNER JOIN.

fn left_outer_join<Rhs>(self, rhs: Rhs) -> LeftJoin<Self, Rhs>

where Self: JoinWithImplicitOnClause<Rhs, LeftOuter>,

Join two tables using a SQL LEFT OUTER JOIN.

fn left_join<Rhs>(self, rhs: Rhs) -> LeftJoin<Self, Rhs>

where Self: JoinWithImplicitOnClause<Rhs, LeftOuter>,

Alias for left_outer_join.

fn filter<Predicate>(self, predicate: Predicate) -> Filter<Self, Predicate>

where Self: FilterDsl<Predicate>,

Adds to the WHERE clause of a query.

fn or_filter<Predicate>(self, predicate: Predicate) -> OrFilter<Self, Predicate>

where Self: OrFilterDsl<Predicate>,

Adds to the WHERE clause of a query using OR

fn find<PK>(self, id: PK) -> Find<Self, PK>

where Self: FindDsl<PK>,

Attempts to find a single record from the given table by primary key.

fn order<Expr>(self, expr: Expr) -> Order<Self, Expr>

where Expr: Expression, Self: OrderDsl<Expr>,

Sets the order clause of a query.

fn order_by<Expr>(self, expr: Expr) -> OrderBy<Self, Expr>

where Expr: Expression, Self: OrderDsl<Expr>,

Alias for order

fn then_order_by<Order>(self, order: Order) -> ThenOrderBy<Self, Order>

where Self: ThenOrderDsl<Order>,

Appends to the ORDER BY clause of this SQL query.

fn limit(self, limit: i64) -> Limit<Self>

where Self: LimitDsl,

Sets the limit clause of the query.

fn offset(self, offset: i64) -> Offset<Self>

where Self: OffsetDsl,

Sets the offset clause of the query.

fn group_by<GB>(self, group_by: GB) -> GroupBy<Self, GB>

where GB: Expression, Self: GroupByDsl<GB>,

Sets the group by clause of a query.

fn having<Predicate>(self, predicate: Predicate) -> Having<Self, Predicate>

where Self: HavingDsl<Predicate>,

Adds to the HAVING clause of a query.

fn for_update(self) -> ForUpdate<Self>

where Self: LockingDsl<ForUpdate>,

Adds FOR UPDATE to the end of the select statement.

fn for_no_key_update(self) -> ForNoKeyUpdate<Self>

where Self: LockingDsl<ForNoKeyUpdate>,

Adds FOR NO KEY UPDATE to the end of the select statement.

fn for_share(self) -> ForShare<Self>

where Self: LockingDsl<ForShare>,

Adds FOR SHARE to the end of the select statement.

fn for_key_share(self) -> ForKeyShare<Self>

where Self: LockingDsl<ForKeyShare>,

Adds FOR KEY SHARE to the end of the select statement.

fn into_boxed<'a, DB>(self) -> IntoBoxed<'a, Self, DB>

where DB: Backend, Self: BoxedDsl<'a, DB>,

Boxes the pieces of a query into a single type.

impl<S, DB> QueryFragment<DB> for Alias<S>

where S: AliasSource, DB: Backend, Self: QueryFragment<DB, DB::AliasSyntax>,

fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()>

Walk over this QueryFragment for all passes.

fn to_sql(&self, out: &mut DB::QueryBuilder, backend: &DB) -> QueryResult<()>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Converts this QueryFragment to its SQL representation.

fn collect_binds<'b>( &'b self, out: &mut DB::BindCollector<'b>, metadata_lookup: &mut DB::MetadataLookup, backend: &'b DB, ) -> QueryResult<()>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Serializes all bind parameters in this query.

fn is_safe_to_cache_prepared(&self, backend: &DB) -> QueryResult<bool>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Is this query safe to store in the prepared statement cache?

fn is_noop(&self, backend: &DB) -> QueryResult<bool>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Does walking this AST have any effect?

impl<S, DB> QueryFragment<DB, AsAliasSyntax> for Alias<S>

where S: AliasSource, DB: Backend, S::Target: QueryFragment<DB>,

fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()>

Walk over this QueryFragment for all passes.

fn to_sql(&self, out: &mut DB::QueryBuilder, backend: &DB) -> QueryResult<()>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Converts this QueryFragment to its SQL representation.

fn collect_binds<'b>( &'b self, out: &mut DB::BindCollector<'b>, metadata_lookup: &mut DB::MetadataLookup, backend: &'b DB, ) -> QueryResult<()>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Serializes all bind parameters in this query.

fn is_safe_to_cache_prepared(&self, backend: &DB) -> QueryResult<bool>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Is this query safe to store in the prepared statement cache?

fn is_noop(&self, backend: &DB) -> QueryResult<bool>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Does walking this AST have any effect?

impl<S> QueryId for Alias<S>

where Self: 'static, S: AliasSource, S::Target: QueryId,

const HAS_STATIC_QUERY_ID: bool = <S::Target as QueryId>::HAS_STATIC_QUERY_ID

Can the SQL generated by Self be uniquely identified by its type?

type QueryId = Alias<S>

A type which uniquely represents Self in a SQL query.

fn query_id() -> Option<TypeId>

Returns the type id of Self::QueryId if Self::HAS_STATIC_QUERY_ID. Returns None otherwise.

impl<S> QuerySource for Alias<S>

where Self: Clone, S: AliasSource, S::Target: QuerySource, <S::Target as QuerySource>::DefaultSelection: FieldAliasMapper<S>, <<S::Target as QuerySource>::DefaultSelection as FieldAliasMapper<S>>::Out: SelectableExpression<Self>,

type FromClause = Alias<S>

The type returned by from_clause

type DefaultSelection = <<<S as AliasSource>::Target as QuerySource>::DefaultSelection as FieldAliasMapper<S>>::Out

The type returned by default_selection

fn from_clause(&self) -> Self::FromClause

The actual FROM clause of this type. This is typically only called in QueryFragment implementations.

fn default_selection(&self) -> Self::DefaultSelection

The default select clause of this type, which should be used if no select clause was explicitly specified. This should always be a tuple of all the desired columns, not star

impl<S: AliasSource, Conn> RunQueryDsl<Conn> for Alias<S>

fn execute(self, conn: &mut Conn) -> QueryResult<usize>

where Conn: Connection, Self: ExecuteDsl<Conn>,

Executes the given command, returning the number of rows affected.

fn load<'query, U>(self, conn: &mut Conn) -> QueryResult<Vec<U>>

where Self: LoadQuery<'query, Conn, U>,

Executes the given query, returning a Vec with the returned rows.

fn load_iter<'conn, 'query: 'conn, U, B>( self, conn: &'conn mut Conn, ) -> QueryResult<Self::RowIter<'conn>>

where U: 'conn, Self: LoadQuery<'query, Conn, U, B> + 'conn,

Executes the given query, returning an Iterator with the returned rows.

fn get_result<'query, U>(self, conn: &mut Conn) -> QueryResult<U>

where Self: LoadQuery<'query, Conn, U>,

Runs the command, and returns the affected row.

fn get_results<'query, U>(self, conn: &mut Conn) -> QueryResult<Vec<U>>

where Self: LoadQuery<'query, Conn, U>,

Runs the command, returning an Vec with the affected rows.

fn first<'query, U>(self, conn: &mut Conn) -> QueryResult<U>

where Self: LimitDsl, Limit<Self>: LoadQuery<'query, Conn, U>,

Attempts to load a single record.

impl<S, Selection> SelectDsl<Selection> for Alias<S>

where Selection: Expression, Self: AsQuery, <Self as AsQuery>::Query: SelectDsl<Selection>,

type Output = <<Alias<S> as AsQuery>::Query as SelectDsl<Selection>>::Output

The type returned by .select

fn select(self, selection: Selection) -> Self::Output

See the trait documentation

impl<S, Expr> ThenOrderDsl<Expr> for Alias<S>

where Expr: Expression, Self: AsQuery, <Self as AsQuery>::Query: ThenOrderDsl<Expr>,

type Output = <<Alias<S> as AsQuery>::Query as ThenOrderDsl<Expr>>::Output

The type returned by .then_order_by.

fn then_order_by(self, expr: Expr) -> Self::Output

See the trait documentation.

impl<S: Copy> Copy for Alias<S>

impl<S2, S> JoinTo<Alias<S2>> for Alias<S>

where S2: AliasSource, S: AliasSource + Default, S::Target: JoinTo<Alias<S2>>, <S::Target as JoinTo<Alias<S2>>>::OnClause: FieldAliasMapper<S>,

impl<T, S> JoinTo<T> for Alias<S>

where T: Table, S: AliasSource + Default, S::Target: JoinTo<T>, <S::Target as JoinTo<T>>::OnClause: FieldAliasMapper<S>,

impl<S, C> SelectableExpression<Alias<S>> for AliasedField<S, C>

where S: AliasSource, C: Column<Table = S::Target>, Self: AppearsOnTable<Alias<S>>,