Struct diesel::query_builder::UpdateStatement

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pub struct UpdateStatement<T: QuerySource, U, V = SetNotCalled, Ret = NoReturningClause> { /* private fields */ }
Expand description

Represents a complete UPDATE statement.

See update for usage examples, or the update guide for a more exhaustive set of examples.

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impl<T: QuerySource, U> UpdateStatement<T, U, SetNotCalled>

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pub fn set<V>(self, values: V) -> UpdateStatement<T, U, V::Changeset>
where T: Table, V: AsChangeset<Target = T>, UpdateStatement<T, U, V::Changeset>: AsQuery,

Provides the SET clause of the UPDATE statement.

See update for usage examples, or the update guide for a more exhaustive set of examples.

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impl<T: QuerySource, U, V, Ret> UpdateStatement<T, U, V, Ret>

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

Adds the given predicate to the WHERE clause of the statement being constructed.

If there is already a WHERE clause, the predicate will be appended with AND. There is no difference in behavior between update(table.filter(x)) and update(table).filter(x).

§Example
let updated_rows = diesel::update(users)
    .set(name.eq("Jim"))
    .filter(name.eq("Sean"))
    .execute(connection);
assert_eq!(Ok(1), updated_rows);

let expected_names = vec!["Jim".to_string(), "Tess".to_string()];
let names = users.select(name).order(id).load(connection);

assert_eq!(Ok(expected_names), names);
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pub fn into_boxed<'a, DB>(self) -> IntoBoxed<'a, Self, DB>
where DB: Backend, Self: BoxedDsl<'a, DB>,

Boxes the WHERE clause of this update statement.

This is useful for cases where you want to conditionally modify a query, but need the type to remain the same. The backend must be specified as part of this. It is not possible to box a query and have it be useable on multiple backends.

A boxed query will incur a minor performance penalty, as the query builder can no longer be inlined by the compiler. For most applications this cost will be minimal.

§Example
let mut query = diesel::update(users)
    .set(name.eq("Jerk"))
    .into_boxed();

if !params["tess_has_been_a_jerk"] {
    query = query.filter(name.ne("Tess"));
}

let updated_rows = query.execute(connection)?;
assert_eq!(1, updated_rows);

let expected_names = vec!["Jerk", "Tess"];
let names = users.select(name).order(id).load::<String>(connection)?;

assert_eq!(expected_names, names);
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impl<T: QuerySource, U, V> UpdateStatement<T, U, V, NoReturningClause>

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pub fn returning<E>( self, returns: E ) -> UpdateStatement<T, U, V, ReturningClause<E>>
where T: Table, UpdateStatement<T, U, V, ReturningClause<E>>: Query,

Specify what expression is returned after execution of the update.

§Examples
§Updating a single record:
let updated_name = diesel::update(users.filter(id.eq(1)))
    .set(name.eq("Dean"))
    .returning(name)
    .get_result(connection);
assert_eq!(Ok("Dean".to_string()), updated_name);

Trait Implementations§

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impl<T, U, V> AsQuery for UpdateStatement<T, U, V, NoReturningClause>

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type SqlType = <<UpdateStatement<T, U, V> as AsQuery>::Query as Query>::SqlType

The SQL type of Self::Query
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type Query = UpdateStatement<T, U, V, ReturningClause<<T as Table>::AllColumns>>

What kind of query does this type represent?
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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.
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impl<'a, T, U, V, Ret, DB> BoxedDsl<'a, DB> for UpdateStatement<T, U, V, Ret>
where T: QuerySource, U: Into<BoxedWhereClause<'a, DB>>,

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type Output = UpdateStatement<T, BoxedWhereClause<'a, DB>, V, Ret>

The return type of internal_into_boxed
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fn internal_into_boxed(self) -> Self::Output

See the trait documentation.
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impl<T: Clone + QuerySource, U: Clone, V: Clone, Ret: Clone> Clone for UpdateStatement<T, U, V, Ret>
where T::FromClause: Clone,

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fn clone(&self) -> UpdateStatement<T, U, V, Ret>

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<T: Debug + QuerySource, U: Debug, V: Debug, Ret: Debug> Debug for UpdateStatement<T, U, V, Ret>
where T::FromClause: Debug,

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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<T, U, V, Ret, Predicate> FilterDsl<Predicate> for UpdateStatement<T, U, V, Ret>
where T: QuerySource, U: WhereAnd<Predicate>, Predicate: AppearsOnTable<T>,

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type Output = UpdateStatement<T, <U as WhereAnd<Predicate>>::Output, V, Ret>

The type returned by .filter.
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fn filter(self, predicate: Predicate) -> Self::Output

See the trait documentation.
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impl<T, U, V, Ret> Query for UpdateStatement<T, U, V, ReturningClause<Ret>>

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type SqlType = <Ret as Expression>::SqlType

The SQL type that this query represents. Read more
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impl<T, U, V, Ret, DB> QueryFragment<DB> for UpdateStatement<T, U, V, Ret>

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fn walk_ast<'b>(&'b self, 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::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. Read more
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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. Read more
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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? Read more
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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?
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impl<T, U, V, Ret> QueryId for UpdateStatement<T, U, V, Ret>
where T: QuerySource,

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type QueryId = ()

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

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<T: QuerySource, U, V, Ret, Conn> RunQueryDsl<Conn> for UpdateStatement<T, U, V, Ret>

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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. Read more
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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. Read more
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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. Read more
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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. Read more

Auto Trait Implementations§

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impl<T, U, V, Ret> Freeze for UpdateStatement<T, U, V, Ret>
where <T as QuerySource>::FromClause: Freeze, U: Freeze, V: Freeze, Ret: Freeze,

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impl<T, U, V, Ret> RefUnwindSafe for UpdateStatement<T, U, V, Ret>

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impl<T, U, V, Ret> Send for UpdateStatement<T, U, V, Ret>
where <T as QuerySource>::FromClause: Send, U: Send, V: Send, Ret: Send,

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impl<T, U, V, Ret> Sync for UpdateStatement<T, U, V, Ret>
where <T as QuerySource>::FromClause: Sync, U: Sync, V: Sync, Ret: Sync,

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impl<T, U, V, Ret> Unpin for UpdateStatement<T, U, V, Ret>
where <T as QuerySource>::FromClause: Unpin, U: Unpin, V: Unpin, Ret: Unpin,

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impl<T, U, V, Ret> UnwindSafe for UpdateStatement<T, U, V, Ret>

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> AsQuery for T
where T: Query,

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type SqlType = <T as Query>::SqlType

The SQL type of Self::Query
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type Query = T

What kind of query does this type represent?
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fn as_query(self) -> <T as AsQuery>::Query

Converts a type which semantically represents a SQL query into the actual query being executed. See the trait level docs for 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) -> AsExprOf<Self, T>

Convert self to an expression for Diesel’s query builder. Read more
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fn as_sql<'a, T>(&'a self) -> AsExprOf<&'a Self, T>

Convert &self to an expression for Diesel’s query builder. Read more
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impl<T, DB> QueryFragmentForCachedStatement<DB> for T
where DB: Backend, <DB as Backend>::QueryBuilder: Default, T: QueryFragment<DB>,

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fn construct_sql(&self, backend: &DB) -> Result<String, Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Convert the query fragment into a SQL string for the given backend
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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.
Check whether it’s safe to cache the query
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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