使用linq或c＃过滤Datatable动态/多重条件？

Question

I have datatable dtResult and it's columns are

BuildSequence,
Build#, 
BOptions,
BJob, 
LogID BType, 
BTypeKey, 
BComponentName, 
BCKey, 
RName, 
Rkey, 
RDescrip, 
RStatus, 
BuildMatchExp,
VPart, 
PNumber, 
SName, 
SKey, 
OName, 
OKey, 
Date

Now i have few filters, these filters are created dynamically and then user can select those filters. These filters are the columns names of dtResult. I have list of selected filters and list contains the FilterName and Its Value. my question is based on Selected filters how i can filter dtResult? As these filters are not constant they are changing every time. Changing every time i mean users are allowed to select any Filter.

eg; in one situation user can select BTypeKey and/or BCKey and/or Rkey in-short they can select any filter or no filter.

Now i can filter dResult based on "Fixed" Column but i am not sure how i can do filtration on dynamic filters? Or How i can use linq to do it?

Any Help will be really appreciated, as i am struggling with it.

At code side so far i have just FilterList as this

FilterParameters filterlist = new FilterParameters(); 
filterlist.Add(new FilterParameter(this._BuildSequence, this._BuildSequenceName, FilterParameterTypes.Guid, FilterComparisonTypes.BuildSequence)); 
filterlist.Add(new FilterParameter(this._BCKey, this._BComponentName, FilterParameterTypes.Guid, FilterComparisonTypes.BCKey)); 
filterlist.Add(new FilterParameter(this._BTypeKey, base.BTypeName, FilterParameterTypes.Guid, FilterComparisonTypes.BTypeKey)); 
return filterlist; 

Thanks

Answer 1

I think the way I'd approach this would be to have Filter objects that act on the IQueryable returned by the base query. Then map the Filter objects to the filters selected by users.

For instance:

class SomeDbContext : DbContext
{
    public IDbSet<Person> People { get; set; }
}

class Person
{
    public string Foreame { get; set; }
    public string Surname { get; set; }
    public int Age { get; set; }
}

abstract class PersonFilter
{
    public abstract IQueryable<Person> Filter(IQueryable<Person> query, string value);
}

class PersonForenameFilter : PersonFilter
{
    public override IQueryable<Person> Filter(IQueryable<Person> query, string value)
    {
        return query.Where(t => t.Foreame == value);
    }
}

class PersonAgeFilter : PersonFilter
{
    public override IQueryable<Person> Filter(IQueryable<Person> query, string value)
    {
        return query.Where(t => t.Age.ToString() == value);
    }
}

Then you can create a mapping using say a Dictionary between a friendly label selectable by the user and the Filter object. Then you just do:

string filterValue = "Dave";
var someFilter = new PersonForenameFilter();
var baseQuery = dbContext.People;
var filteredQuery = someFilter.Filter(baseQuery, filterValue);

Where someFilter is actually retrieved from your mapping dictionary.

Also, note that this is composable so you could apply more than one filter.

Answer 2

Thanks @MethodMan, your DataTable.Select Method did work and i converted my Filterlist to expression by using

var a = filterList.GroupBy(g => g.ParameterName).Select(gr => 
    string.Format("{0}={1}", gr.First().ParameterName, string.Join(",", gr.Select(g => g.Value))));
var b = string.Join(" And ", a.ToArray());

However, I am still stick to passing SQL Parameters to a stored procedure because one of the parameters is csv (and i have used Split for csv at database end) and expression for Select method has to be like ID=1 and Name='abc' and Address='here' and city='there' but if you want Name to be 'abc' or 'xyz' you need ".. and Name='abc' or Name='xyz' but its comma separated value for me like Name={'abc,xyz'} and I wasn't able to convert Name to Name='abc' or Name='xyz' .