Enum HandlerReadSelector 

pub enum HandlerReadSelector<X: Extension = NoExt> {
    Scan {
        direction: HandlerScanDirection,
        meta: Meta,
    },
    Index {
        index: Ident,
        direction: HandlerIndexDirection,
        meta: Meta,
    },
    Key {
        index: Ident,
        comparison: HandlerKeyComparison,
        key: ThinVec<ValuesItem<X>>,
        meta: Meta,
    },
}

The row-selection shape of a HANDLER … READ (sql_yacc.yy handler_scan_function / handler_rkey_function / handler_rkey_mode), independent of the shared WHERE/LIMIT tail carried by HandlerOperation::Read.

Variants

Scan

READ { FIRST | NEXT } — a full scan in storage order with no index named. Restricted to FIRST/NEXT (HandlerScanDirection); PREV/LAST require a named index (HANDLER t READ PREV is ER_PARSE_ERROR on mysql:8).

Fields

direction: HandlerScanDirection

The scan direction (FIRST/NEXT only).

meta: Meta

Source location and node identity.

Index

READ <index> { FIRST | NEXT | PREV | LAST } — traverse a named index in the given direction (HandlerIndexDirection, the wider PREV/LAST set). A PRIMARY key is spelled with the reserved word quoted (READ `PRIMARY`).

Fields

index: Ident

The index name.

direction: HandlerIndexDirection

The traversal direction (FIRST/NEXT/PREV/LAST).

meta: Meta

Source location and node identity.

Key

READ <index> <op> ( <value> [, …] ) — seek a named index by key: position at the first row whose index value satisfies comparison against the key tuple. The key is a non-empty expr_or_default list (ValuesItem, so a bare DEFAULT element is admitted like the INSERT values path); ( ) is ER_PARSE_ERROR on mysql:8.

Fields

index: Ident

The index name.

comparison: HandlerKeyComparison

The key comparison operator; see HandlerKeyComparison.

key: ThinVec<ValuesItem<X>>

The key tuple, a non-empty list of value expressions (DEFAULT admitted).

meta: Meta

Source location and node identity.

Trait Implementations

impl<X: Clone + Extension> Clone for HandlerReadSelector<X>

fn clone(&self) -> HandlerReadSelector<X>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<X: Debug + Extension> Debug for HandlerReadSelector<X>

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

Formats the value using the given formatter.

impl<'de, X> Deserialize<'de> for HandlerReadSelector<X>

where X: Deserialize<'de> + Extension,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<X: Eq + Extension> Eq for HandlerReadSelector<X>

impl<X: Hash + Extension> Hash for HandlerReadSelector<X>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<X: PartialEq + Extension> PartialEq for HandlerReadSelector<X>

fn eq(&self, other: &HandlerReadSelector<X>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<X: Extension + Render> Render for HandlerReadSelector<X>

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

Return the render for this value.

fn operand_binding_power(&self) -> Option<BindingPower>

The binding power this node contributes when it appears as an operand, or None (the default) for a self-delimiting node — an atom, call, or constructor — that never needs parentheses.

impl<X> Serialize for HandlerReadSelector<X>

where X: Serialize + Extension,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<X: Extension> Spanned for HandlerReadSelector<X>

fn span(&self) -> Span

Return the span for this value.

impl<X: PartialEq + Extension> StructuralPartialEq for HandlerReadSelector<X>