Or between Where operators

If I would run a query like this:

.Where(ts => ts.p_tsID == 10)

       .Where(ts => ts.p_tsID == 20);

Query((IEntityQuery<EntTs>)query, callback);

it would return empty because there is an AND between the two Where operators – so an ID cannot be 10 and 20 at the same time.

Can I make my own OrWhere operator?

And does anyone know how to do that?

Sbelini,

I know. But what I want, is to build my query dynamically – something like this:

var query = p_manager.EntTsSet;

if (Something)

query = query.Where(ts => ts.p_tsID == 10);

if (SomethingElse)

query = query.Where(ts => ts.p_tsID == 20);

query = query.OrderBy(ts => ts.p_tsID);

Query((IEntityQuery<EntTs>)query, callback);

This is just a simple example. I want to be able to construct more complex queries dynamically, based on that a user enters in a search dialog.

Thanx sbelini!

Looks interesting! I will look into this.

Here is what I am working on at the moment:

The user can search for some items by typing some intervals of ids in a search dialog.

The user would for example type this: 10-20,40-45,100-110

Meaning that the user wants to see the items whose ids range from 10 to 20 and 40 to 45 and 100 to 110.

I would make my query dynamically like this, because I do not know how many intervals the user is going to type into the search dialog:

IQueryable<EntTs> query = p_manager.EntTsSet;

var strings = param.Split(',');

foreach (string s in strings)

{

var intervals = s.Split('-');

       query = query.Where(ts => ts.p_tsID >= Int32.Parse(intervals[0].Trim()) && ts.p_tsID <= Int32.Parse(intervals[1].Trim()));

}

query = query.OrderBy(ts => ts.p_tsID);

Query((IEntityQuery<EntTs>) query, callback);

But this does not work because this returns only 100 to 110. But if the Where operators had an Or between them I would get the union, which is that I want.

Thanx again sbelini!

This PredicateBuilder is excellent!

This is exactly what I was looking for!

Here is what my query ends up looking like:

var predicate = PredicateBuilder.True<EntTs>();

var strings = param.p_text.Split(',');

foreach (string s in strings)

{

var intervals = s.Split('-');

       predicate = predicate.Or(ts => ts.p_tsID >= Int32.Parse(intervals[0].Trim()) && ts.p_tsID <= Int32.Parse(intervals[1].Trim()));

}

var query = p_manager.EntTsSet.Where(predicate);

query = query.OrderBy(ts => ts.p_tsID);

Query(query,callback);

And if I use the help from my JetBrains Reshaper, it ends up looking like this:

var predicate = PredicateBuilder.True<EntTs>();

var strings = param.p_text.Split(',');

predicate = strings.Select(s => s.Split('-')).Aggregate(predicate, (current, intervals) => current.Or(ts => ts.p_tsID >= Int32.Parse(intervals[0].Trim()) && ts.p_tsID <= Int32.Parse(intervals[1].Trim())));

var query = p_manager.EntTsSet.Where(predicate);

query = query.OrderBy(ts => ts.p_tsID);

Query(query,callback);

Just love it!