Struct CaseBuilder 

pub struct CaseBuilder<'a, V: SQLParam, T: DataType, N: Nullability, A: AggregateKind> { /* private fields */ }

Builder state after at least one WHEN branch has been added.

The result type T and accumulated nullability N are tracked.

Implementations

impl<'a, V, T, N, A> CaseBuilder<'a, V, T, N, A>

where V: SQLParam + 'a, T: DataType, N: Nullability, A: AggregateKind,

pub fn when<C, R>( self, condition: C, result: R, ) -> CaseBuilder<'a, V, T, <N as NullOr<R::Nullable>>::Output, <<A as AggOr<C::Aggregate>>::Output as AggOr<R::Aggregate>>::Output>

where C: Expr<'a, V>, R: Expr<'a, V>, C::SQLType: BooleanLike, T: Compatible<R::SQLType>, N: NullOr<R::Nullable>, R::Nullable: Nullability, A: AggOr<C::Aggregate>, <A as AggOr<C::Aggregate>>::Output: AggOr<R::Aggregate>, C::Aggregate: AggregateKind, R::Aggregate: AggregateKind,

Add another WHEN branch.

The result type must be compatible with the type established by the first branch. Nullability is accumulated via NullOr.

pub fn end(self) -> SQLExpr<'a, V, T, Null, A>

Finish the CASE expression without an ELSE clause.

Without ELSE, unmatched rows produce NULL, so the result is always Null regardless of branch nullability.

pub fn else<D>( self, default: D, ) -> SQLExpr<'a, V, T, <N as NullOr<D::Nullable>>::Output, <A as AggOr<D::Aggregate>>::Output>

where D: Expr<'a, V>, T: Compatible<D::SQLType>, N: NullOr<D::Nullable>, D::Nullable: Nullability, A: AggOr<D::Aggregate>, D::Aggregate: AggregateKind,

Finish the CASE expression with an ELSE clause.

The ELSE value must have a compatible type. Nullability is the combination of all branch nullabilities and the default’s nullability.