Function when

datafusion/expr/src/expr_fn.rs:385–387

Create a CASE WHEN statement with boolean WHEN expressions and no base expression.

(when: Expr, then: Expr)

/// Create a CASE WHEN statement with boolean WHEN expressions and no base expression.
pub fn when(when: Expr, then: Expr) -> CaseBuilder {
    CaseBuilder::new(None, vec![when], vec![then], None)
}

/// Create a Unnest expression
pub fn unnest(expr: Expr) -> Expr {