Enum SetVariableAssignment 

pub enum SetVariableAssignment<X: Extension = NoExt> {
    SystemVariable {
        scope: SystemVariableScope,
        name: ObjectName,
        assignment: SetAssignment,
        value: SetVariableValue<X>,
        meta: Meta,
    },
    UserVariable {
        name: Ident,
        assignment: SetAssignment,
        value: Box<Expr<X>>,
        meta: Meta,
    },
}

One item of a MySQL SetVariables list: a system variable assignment (with an optional scope on either the keyword or @@ axis) or a user-defined @var assignment.

Variants

SystemVariable

A system-variable assignment: [GLOBAL|SESSION|LOCAL|PERSIST|PERSIST_ONLY] <name> or @@[scope.]<name>, then {= | :=} and a set_expr_or_default value. The scope spelling (keyword prefix vs @@ sigil) is captured in scope; the two are mutually exclusive in the grammar (SET GLOBAL @@x = 1 is a syntax error).

Fields

scope: SystemVariableScope

The scope qualifier and its spelling; see SystemVariableScope.

name: ObjectName

The (optionally dotted) variable name.

assignment: SetAssignment

Which of the exact-synonym = / := separators the source wrote.

value: SetVariableValue<X>

The new value; see SetVariableValue.

meta: Meta

Source location and node identity.

UserVariable

A user-defined @var := <expr> / @var = <expr> assignment. The value is a full expression (@v = a + 1, @v = (SELECT ...)); the sentinels a system variable admits (DEFAULT/ON/…) are not valid here, matching the grammar’s plain expr.

Fields

name: Ident

The user-variable name (sigil stripped), with its source quote style for round-trip.

assignment: SetAssignment

Which of the exact-synonym = / := separators the source wrote.

value: Box<Expr<X>>

The assigned expression.

meta: Meta

Source location and node identity.

Trait Implementations

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

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

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

Formats the value using the given formatter.

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

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

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

Equality operator ==.

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

Inequality operator !=.

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

fn span(&self) -> Span

Return the span for this value.

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