How to check a string character by character in C# linq

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Hi Friends,
I have a field in my database table as "SimCardNumber",
Now, I have a form for search SimCard Number and users can put numbers in the specific position.
for example they will search for 9*2***54**
and i want to show whatever "SimCardNumber" from my table which is in this pattern.
I need a query for it.
thank's for your help

What I have tried:

C#

public IQueryable<SimCardOutPut> GetSimCardBySearch(string number)
        {
            var context = new Entities();
            var simcard = context.SimCards;
            var operators = context.Operators;
            var rondtype = context.RondTypes;
            var city = context.Cities;
            var query = from s in simcard
                        join o in operators on s.IdOperatorFK equals o.IdOperator
                        join r in rondtype on s.IdRondTypeFK equals r.IdRondType
                        join c in city on s.IdCityFK equals c.IdCity
                        where
                            s.Number.Contains(number)
                        select new SimCardOutPut()
                        {
                            IdSimCard = s.IdSimCard,
                            Operator = o.Title,
                            RondType = r.Title,
                            City = c.Title,
                            Number = s.Number,
                            Type = s.Type,
                            Status = s.Status,
                            Quality = s.Quality,
                            Seller = s.Seller,
                            Price = (Int64)s.Price,
                            ShowType = s.ShowType,
                            Active = (Boolean)s.Active
                        };
            return query;
        }

Posted 3-Nov-16 6:47am

hamid-shrk

Updated 3-Nov-16 17:43pm

v3

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3 solutions

Solution 1

Possibly a Regex would be simplest to implement here

C#

Regex r = new Regex(number.Replace("*", @"\d"));
....

where r.Match(s.Number).Success

Posted 3-Nov-16 7:02am

Midi_Mick

Comments

Richard Deeming 3-Nov-16 13:16pm

Good luck getting your database to recognise that! :)

Solution 4

Just a dew useful links for RegEx

Here is a link to RegEx documentation:
perlre - perldoc.perl.org[^]
Here is links to tools to help build RegEx and debug them:
.NET Regex Tester - Regex Storm[^]
Expresso Regular Expression Tool[^]
This one show you the RegEx as a nice graph which is really helpful to understand what is doing a RegEx:
Debuggex: Online visual regex tester. JavaScript, Python, and PCRE.[^]

Posted 3-Nov-16 17:43pm

Patrice T

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Richard Deeming · Accepted Answer · 2016-11-03T07:31:00

Unfortunately, there's no LIKE function in Entity Framework, and with Code First, there doesn't seem to be an option to create one.

However, if you add a reference to the EntityFramework.SqlServer assembly, you can use the SqlFunctions.PatIndex[^] method. Unfortunately, it won't be as quick as a LIKE query, but it should be faster than loading all of the data and filtering client-side.

C#

public IQueryable<SimCardOutPut> GetSimCardBySearch(string number)
{
    string sqlPattern = number.Replace('*', '_');
    
    var context = new Entities();
    var simcard = context.SimCards;
    var operators = context.Operators;
    var rondtype = context.RondTypes;
    var city = context.Cities;
    var query = from s in simcard
                join o in operators on s.IdOperatorFK equals o.IdOperator
                join r in rondtype on s.IdRondTypeFK equals r.IdRondType
                join c in city on s.IdCityFK equals c.IdCity
                where
                    SqlFunctions.PatIndex(sqlPattern, s.Number) != 0
                select new SimCardOutPut()
                {
                    IdSimCard = s.IdSimCard,
                    Operator = o.Title,
                    RondType = r.Title,
                    City = c.Title,
                    Number = s.Number,
                    Type = s.Type,
                    Status = s.Status,
                    Quality = s.Quality,
                    Seller = s.Seller,
                    Price = (Int64)s.Price,
                    ShowType = s.ShowType,
                    Active = (Boolean)s.Active
                };
    return query;
}