Method normalize

pkg/sql/sem/tree/normalize.go:29–61

(v *NormalizeVisitor)

}

func (expr *CoalesceExpr) normalize(v *NormalizeVisitor) TypedExpr {
	// This normalization checks whether COALESCE can be simplified
	// based on constant expressions at the start of the COALESCE
	// argument list. All known-null constant arguments are simply
	// removed, and any known-nonnull constant argument before
	// non-constant argument cause the entire COALESCE expression to
	// collapse to that argument.
	last := len(expr.Exprs) - 1
	for i := range expr.Exprs {
		subExpr := expr.TypedExprAt(i)

		if i == last {
			return subExpr
		}

		if !v.isConst(subExpr) {
			exprCopy := *expr
			exprCopy.Exprs = expr.Exprs[i:]
			return &exprCopy
		}

		val, err := subExpr.Eval(v.ctx)
		if err != nil {
			v.err = err
			return expr
		}

		if val != DNull {
			return subExpr
		}
	}
	return expr
}

func (expr *IfExpr) normalize(v *NormalizeVisitor) TypedExpr {
	if v.isConst(expr.Cond) {