Struct tidb_query_aggr::impl_max_min::AggFnStateExtremumForEnum

pub struct AggFnStateExtremumForEnum<E> where
    E: Extremum,
    VectorValue: VectorValueExt<Enum>,  {
    extremum: Option<Enum>,
    _phantom: PhantomData<E>,
}

Fields

extremum: Option<Enum>

_phantom: PhantomData<E>

Implementations

impl<E> AggFnStateExtremumForEnum<E> where
    E: Extremum,
    VectorValue: VectorValueExt<Enum>, 

pub fn new() -> Self

fn update_concrete(
    &mut self,
    _ctx: &mut EvalContext,
    value: Option<EnumRef<'_>>
) -> Result<()>

Notes

For MAX(), MySQL currently compares ENUM and SET columns by their string value rather than by the string’s relative position in the set. This differs from how ORDER BY compares them.

ref: https://dev.mysql.com/doc/refman/5.7/en/aggregate-functions.html#function_max

Trait Implementations

impl<E> ConcreteAggrFunctionState for AggFnStateExtremumForEnum<E> where
    E: Extremum,
    VectorValue: VectorValueExt<Enum>, 

type ParameterType = EnumRef<'static>

unsafe fn update_concrete_unsafe(
    &mut self,
    ctx: &mut EvalContext,
    value: Option<Self::ParameterType>
) -> Result<()>

Safety

fn push_result(
    &self,
    _ctx: &mut EvalContext,
    target: &mut [VectorValue]
) -> Result<()>

impl<E: Debug> Debug for AggFnStateExtremumForEnum<E> where
    E: Extremum,
    VectorValue: VectorValueExt<Enum>, 

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

Formats the value using the given formatter.