Struct ExprIsNull 

pub struct ExprIsNull {
    pub expr: Box<Expr>,
    pub negated: bool,
}

Tests whether an expression is null.

Returns true if the expression evaluates to null, or the opposite when negated is set. The flag makes IS NOT NULL a predicate in its own right rather than the negation of IS NULL: statement normalization attaches variant guards to the predicate before expanding the negated form to not(is_null(..)), so the guards end up outside the negation.

Examples

is_null(x)      // returns `true` if x is null
is_not_null(x)  // returns `true` if x is not null

Fields

expr: Box<Expr>

The expression to check for null.

negated: bool

Whether the check is IS NOT NULL.

Trait Implementations

impl Clone for ExprIsNull

fn clone(&self) -> ExprIsNull

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExprIsNull

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

Formats the value using the given formatter.

impl From<ExprIsNull> for Expr

fn from(value: ExprIsNull) -> Expr

Converts to this type from the input type.

impl PartialEq for ExprIsNull

fn eq(&self, other: &ExprIsNull) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ExprIsNull