protected IsNullExpression UpdateIsNull(IsNullExpression isnull, Expression expression)
{
if (expression != isnull.Expression)
{
return(new IsNullExpression(expression));
}
return(isnull);
}
protected virtual Expression VisitIsNull(IsNullExpression isnull)
{
var expr = Visit(isnull.Expression);
return(UpdateIsNull(isnull, expr));
}
protected virtual bool CompareIsNull(IsNullExpression a, IsNullExpression b)
{
return(this.Compare(a.Expression, b.Expression));
}
protected override Expression VisitIsNull(IsNullExpression isnull)
{
this.VisitValue(isnull.Expression);
this.Write(" IS NULL");
return(isnull);
}
protected Expression MakeIsNull(Expression expression, bool negate)
{
Expression isnull = new IsNullExpression(expression);
return(negate ? Expression.Not(isnull) : isnull);
}