Enum Expr 

pub enum Expr {
    Alias(Alias),
    Column(ColumnExpr),
    Literal(Literal),
    Binary(BinaryExpr),
    Cast(Cast),
    AggregateFunction(AggregateFunction),
}

Variants

Alias(Alias)

An expression with a specific name.

Column(ColumnExpr)

A named reference to a qualified filed in a schema.

Literal(Literal)

A constant value.

Binary(BinaryExpr)

A binary expression such as “age > 21”

Cast(Cast)

Casts the expression to a given type and will return a runtime error if the expression cannot be cast. This expression is guaranteed to have a fixed type.

AggregateFunction(AggregateFunction)

Represents the call of an aggregate built-in function with arguments.

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.

impl Display for Expr

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

Formats the value using the given formatter.

impl ExprTrait for Expr

fn data_type(&self, input_schema: &Schema) -> QuillSQLResult<DataType>

Get the data type of this expression, given the schema of the input

fn nullable(&self, input_schema: &Schema) -> QuillSQLResult<bool>

Determine whether this expression is nullable, given the schema of the input

fn evaluate(&self, tuple: &Tuple) -> QuillSQLResult<ScalarValue>

Evaluate an expression against a Tuple

fn to_column(&self, input_schema: &Schema) -> QuillSQLResult<Column>

convert to a column with respect to a schema

impl PartialEq for Expr

fn eq(&self, other: &Expr) -> 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 Eq for Expr

impl StructuralPartialEq for Expr