Struct relations::schema::books::columns::star

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pub struct star;
Expand description

Represents table_name.*, which is sometimes needed for efficient count queries. It cannot be used in place of all_columns, and has a SqlType of () to prevent it being used that way

Trait Implementations§

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impl Clone for star

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fn clone(&self) -> star

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for star

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

Formats the value using the given formatter. Read more
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impl Expression for star

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type SqlType = NotSelectable

The type that this expression represents in SQL
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impl<DB: Backend> QueryFragment<DB> for star
where <table as QuerySource>::FromClause: QueryFragment<DB>,

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

Walk over this QueryFragment for all passes. Read more
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fn to_sql( &self, out: &mut <DB as Backend>::QueryBuilder, backend: &DB ) -> Result<(), Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Converts this QueryFragment to its SQL representation. Read more
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fn collect_binds<'b>( &'b self, out: &mut <DB as Backend>::BindCollector<'b>, metadata_lookup: &mut <DB as TypeMetadata>::MetadataLookup, backend: &'b DB ) -> Result<(), Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Serializes all bind parameters in this query. Read more
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fn is_safe_to_cache_prepared(&self, backend: &DB) -> Result<bool, Error>

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? Read more
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fn is_noop(&self, backend: &DB) -> Result<bool, Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Does walking this AST have any effect?
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impl QueryId for star

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type QueryId = star

A type which uniquely represents Self in a SQL query. Read more
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const HAS_STATIC_QUERY_ID: bool = true

Can the SQL generated by Self be uniquely identified by its type? Read more
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fn query_id() -> Option<TypeId>

Returns the type id of Self::QueryId if Self::HAS_STATIC_QUERY_ID. Returns None otherwise. Read more
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impl<__GB> ValidGrouping<__GB> for star
where (id, title): ValidGrouping<__GB>,

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type IsAggregate = <(id, title) as ValidGrouping<__GB>>::IsAggregate

Is this expression aggregate? Read more
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impl AppearsOnTable<table> for star

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impl Copy for star

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impl SelectableExpression<table> for star

Auto Trait Implementations§

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impl Freeze for star

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impl RefUnwindSafe for star

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impl Send for star

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impl Sync for star

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impl Unpin for star

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impl UnwindSafe for star

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<Conn, DB, T> ExecuteDsl<Conn, DB> for T
where Conn: Connection<Backend = DB>, DB: Backend, T: QueryFragment<DB> + QueryId,

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fn execute(query: T, conn: &mut Conn) -> Result<usize, Error>

Execute this command
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoSql for T

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fn into_sql<T>(self) -> Self::Expression
where Self: Sized + AsExpression<T>, T: SqlType + TypedExpressionType,

Convert self to an expression for Diesel’s query builder. Read more
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fn as_sql<'a, T>(&'a self) -> <&'a Self as AsExpression<T>>::Expression
where &'a Self: AsExpression<T>, T: SqlType + TypedExpressionType,

Convert &self to an expression for Diesel’s query builder. Read more
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impl<T> NullableExpressionMethods for T
where T: Expression,

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fn nullable(self) -> Nullable<Self>

Converts this potentially non-null expression into one which is treated as nullable. This method has no impact on the generated SQL, and is only used to allow certain comparisons that would otherwise fail to compile. Read more
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fn assume_not_null(self) -> AssumeNotNull<Self>

Converts this potentially nullable expression into one which will be assumed to be not-null. This method has no impact on the generated SQL, however it will enable you to attempt deserialization of the returned value in a non-Option. Read more
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impl<T> PgExpressionMethods for T
where T: Expression,

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fn is_not_distinct_from<T>( self, other: T ) -> Grouped<IsNotDistinctFrom<Self, <T as AsExpression<Self::SqlType>>::Expression>>
where Self::SqlType: SqlType, T: AsExpression<Self::SqlType>,

Creates a PostgreSQL IS NOT DISTINCT FROM expression. Read more
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fn is_distinct_from<T>( self, other: T ) -> Grouped<IsDistinctFrom<Self, <T as AsExpression<Self::SqlType>>::Expression>>
where Self::SqlType: SqlType, T: AsExpression<Self::SqlType>,

Creates a PostgreSQL IS DISTINCT FROM expression. Read more
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impl<T> SqliteExpressionMethods for T
where T: Expression,

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fn is<T>( self, other: T ) -> Grouped<Is<Self, <T as AsExpression<Self::SqlType>>::Expression>>
where Self::SqlType: SqlType, T: AsExpression<Self::SqlType>,

Creates a Sqlite IS expression. Read more
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fn is_not<T>( self, other: T ) -> Grouped<IsNot<Self, <T as AsExpression<Self::SqlType>>::Expression>>
where Self::SqlType: SqlType, T: AsExpression<Self::SqlType>,

Creates a Sqlite IS NOT expression. Read more
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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impl<T> NonAggregate for T
where T: ValidGrouping<()>, <T as ValidGrouping<()>>::IsAggregate: MixedAggregates<No, Output = No>,