Struct diesel::query_builder::UpdateStatement

pub struct UpdateStatement<T, U, V, Ret = NoReturningClause> { /* fields omitted */ }

Represents a complete UPDATE statement.

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

Methods

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

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

impl<T: Debug, U: Debug, V: Debug, Ret: Debug> Debug for UpdateStatement<T, U, V, Ret>

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<T: Copy, U: Copy, V: Copy, Ret: Copy> Copy for UpdateStatement<T, U, V, Ret>

impl<T: Clone, U: Clone, V: Clone, Ret: Clone> Clone for UpdateStatement<T, U, V, Ret>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

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

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

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

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);

impl<T, U, V, Ret, DB> QueryFragment<DB> for UpdateStatement<T, U, V, Ret> where
    DB: Backend,
    T: Table,
    T::FromClause: QueryFragment<DB>,
    U: QueryFragment<DB>,
    V: Changeset<DB>,
    Ret: QueryFragment<DB>, 

fn walk_ast(&self, out: AstPass<DB>) -> QueryResult<()>

Walk over this QueryFragment for all passes.

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

Converts this QueryFragment to its SQL representation

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

Serializes all bind parameters in this query.

fn is_safe_to_cache_prepared(&self) -> QueryResult<bool>

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

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

type QueryId = ()

const HAS_STATIC_QUERY_ID: bool

HAS_STATIC_QUERY_ID: bool = false

fn query_id() -> Option<TypeId>

impl<T, U, V> AsQuery for UpdateStatement<T, U, V, NoReturningClause> where
    T: Table,
    UpdateStatement<T, U, V, ReturningClause<T::AllColumns>>: Query, 

type SqlType = <Self::Query as Query>::SqlType

The SQL type of Self::Query

type Query = UpdateStatement<T, U, V, ReturningClause<T::AllColumns>>

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<T, U, V, Ret> Query for UpdateStatement<T, U, V, ReturningClause<Ret>> where
    T: Table,
    Ret: Expression + SelectableExpression<T> + NonAggregate, 

type SqlType = Ret::SqlType

The SQL type that this query represents.