protected virtual Expression VisitIsNull(IsNullExpression isnull) { var expr = this.Visit(isnull.Expression); return this.UpdateIsNull(isnull, expr); }
protected override Expression VisitIsNull(IsNullExpression isnull) { this.VisitValue(isnull.Expression); this.Write(" IS NULL"); return isnull; }
protected IsNullExpression UpdateIsNull(IsNullExpression isnull, Expression expression) { if (expression != isnull.Expression) { return new IsNullExpression(expression); } return isnull; }
protected virtual bool CompareIsNull(IsNullExpression a, IsNullExpression b) { return this.Compare(a.Expression, b.Expression); }