Struct diesel::query_builder::DeleteStatement

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

Methods

impl<T, U> DeleteStatement<T, U, NoReturningClause>

fn returning<E>(self, returns: E) -> DeleteStatement<T, U, ReturningClause<E>> where
    E: SelectableExpression<T>,
    DeleteStatement<T, U, ReturningClause<E>>: Query, 

Specify what expression is returned after execution of the delete.

Examples

Deleting a record:

let deleted_name = diesel::delete(users.filter(name.eq("Sean")))
    .returning(name)
    .get_result(&connection);
assert_eq!(Ok("Sean".to_string()), deleted_name);

Trait Implementations

impl<T: Debug, U: Debug, Ret: Debug> Debug for DeleteStatement<T, U, Ret>

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

Formats the value using the given formatter.

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

type Output = DeleteStatement<T, U::Output, 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 delete(table.filter(x)) and delete(table).filter(x).

Example

let deleted_rows = diesel::delete(users)
    .filter(name.eq("Sean"))
    .execute(&connection);
assert_eq!(Ok(1), deleted_rows);

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

assert_eq!(Ok(expected_names), names);

impl<T, U, Ret, DB> QueryFragment<DB> for DeleteStatement<T, U, Ret> where
    DB: Backend,
    T: Table,
    T::FromClause: QueryFragment<DB>,
    U: QueryFragment<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, Ret> QueryId for DeleteStatement<T, U, Ret> where
    T: QueryId,
    U: QueryId,
    Ret: QueryId, 

type QueryId = DeleteStatement<T::QueryId, U::QueryId, Ret::QueryId>

const HAS_STATIC_QUERY_ID: bool

HAS_STATIC_QUERY_ID: bool = <T>::HAS_STATIC_QUERY_ID && <U>::HAS_STATIC_QUERY_ID &&
    <Ret>::HAS_STATIC_QUERY_ID && true

fn query_id() -> Option<TypeId>

impl<T, U> AsQuery for DeleteStatement<T, U, NoReturningClause> where
    T: Table,
    T::AllColumns: SelectableExpression<T>,
    DeleteStatement<T, U, ReturningClause<T::AllColumns>>: Query, 

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

The SQL type of Self::Query

type Query = DeleteStatement<T, U, 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, Ret> Query for DeleteStatement<T, U, ReturningClause<Ret>> where
    T: Table,
    Ret: SelectableExpression<T>, 

type SqlType = Ret::SqlType

The SQL type that this query represents.