Struct IndexHint 

pub struct IndexHint {
    pub kind: Option<IndexHintKind>,
    pub indexes: Vec<Cow<'static, str>>,
    pub for_: Option<IndexHintScope>,
}

MySQL’s USE | FORCE | IGNORE INDEX [FOR …] (indexes).

Never contributes a bound argument: index names are identifiers.

Fields

kind: Option<IndexHintKind>

Which hint. None is how a default-constructed hint stays absent.

indexes: Vec<Cow<'static, str>>

The index names, quoted. May be empty — USE INDEX () is how MySQL is told to use no index at all, so the parentheses are unconditional.

for_: Option<IndexHintScope>

Restrict the hint to one phase of planning.

Implementations

impl IndexHint

pub fn new( kind: IndexHintKind, indexes: impl IntoIterator<Item = impl Into<Cow<'static, str>>>, ) -> Self

A hint of kind over indexes, applying to the whole query.

pub fn is_empty(&self) -> bool

Whether the hint is absent.

Trait Implementations

impl Clone for IndexHint

fn clone(&self) -> IndexHint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for IndexHint

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

Formats the value using the given formatter.

impl Default for IndexHint

fn default() -> IndexHint

Returns the “default value” for a type.

impl Expression for IndexHint

fn write_sql(&self, w: &mut SqlWriter<'_>)

Append this fragment to w.