Struct CaseBuilder 

pub struct CaseBuilder { /* private fields */ }

A CASE expression under construction — bob’s CaseChain.

use keelson_core::expr::{case, literal, quote, Chain, arg};

// (CASE WHEN ("id" = $1) THEN 'A' ELSE 'B' END)
let e = case()
    .when(quote("id").eq(arg(1i32)), literal("A"))
    .else_(literal("B"));

end and else_ both apply the parenthesisation rule, so the result is (CASE .. END) — self-delimiting, and safe to drop into an operand slot or alias with Chain::as_.

Implementations

impl CaseBuilder

pub fn new() -> CaseBuilder

An empty CASE. At least one when is required before it can render.

pub fn when(self, condition: impl IntoExpr, then: impl IntoExpr) -> CaseBuilder

Add a WHEN condition THEN result branch.

pub fn else_(self, then: impl IntoExpr) -> Expr

Finish with an ELSE branch.

pub fn end(self) -> Expr

Finish without an ELSE branch.

Trait Implementations

impl Clone for CaseBuilder

fn clone(&self) -> CaseBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CaseBuilder

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

Formats the value using the given formatter.

impl Default for CaseBuilder

fn default() -> CaseBuilder

Returns the “default value” for a type.