Expression predicates with field name with a ToUpper

Question

I have this code :

public static Expression<Func<T, bool>> CreatePredicate<T>(string typeSearch, string searchField, string stringToSearch)
{
    var parameter = Expression.Parameter(typeof(T));
    var predicate = Expression.Lambda<Func<T, bool>>(
        Expression.Call(
            Expression.PropertyOrField(parameter, searchField),
            "Contains", null,
            Expression.Constant(stringToSearch.ToUpper())), parameter);

    return predicate;
}

the result is : {Param_0 => Param_0.Username.Contains("MX")}

But I'd like this : {Param_0 => Param_0.Username.ToUpper().Contains("MX")}

Thanks,

As a side-note: You should specify `InvariantCulture` for your `ToUpper`. — CodesInChaos, Jul 30 '12 at 12:22

score 2 · Accepted Answer · answered Jul 30 '12 at 12:27

2

public static Expression<Func<T, bool>> CreatePredicate<T>(string typeSearch, string searchField, string stringToSearch)
{
    var parameter = Expression.Parameter(typeof(T));
    var predicate = Expression.Lambda<Func<T, bool>>(
        Expression.Call(
            Expression.Call(Expression.PropertyOrField(parameter, searchField), "ToUpper", null),
            "Contains", null,
            Expression.Constant(stringToSearch.ToUpper())), parameter);

    return predicate;
}

answered Jul 30 '12 at 12:27

Sergei Rogovtcev

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Bonus. I have some string with letters with an accent "é,è, ...". Is there a way to treat 'é' as 'e' ? – TheBoubou Jul 30 '12 at 12:45
You'll have to look into `CultureInfo culture` parameter of `ToUpper`. – Sergei Rogovtcev Jul 30 '12 at 12:46
I don't understand your problem. Begin by writing normal, not generated code, which does what you want, *then* convert it to expression. – Sergei Rogovtcev Jul 30 '12 at 12:59
when I do a search on "élève" (student in English) and I do a search contains with "eve", I have no result but I have a result with "ève". I'd like if I search with "ève" or "eve" get "élève" as result. I don't want to consider the accent in the search – TheBoubou Jul 30 '12 at 13:06
http://stackoverflow.com/questions/359827/ignoring-accented-letters-in-string-comparison – Sergei Rogovtcev Jul 30 '12 at 13:11
I saw that but I don't want remove or change my list, I'd like, if possible, add "Culture Info" to the ToUpper in the ExpressionCall and avoid the loop – TheBoubou Jul 30 '12 at 13:15
Either way that has nothing with this question. Please close this one and open another. – Sergei Rogovtcev Jul 30 '12 at 13:35

Expression predicates with field name with a ToUpper

1 Answers1