I have a very typical linq-to-entities data binding in WinForms: myGrid.DataSource = myEntities.entity When it reaches that line of code it simply hangs. Similar assignment a different entity work fine elsewhere in the code. The database contains no more than 50 lines of data in all entities (it's a new project) so it's not waiting on...
Say I have an array of strings: string[] strArray = {"aa", "bb", "xx", "cc", "xx", "dd", "ee", "ff", "xx","xx","gg","xx"}; How do I use LINQ to extract the strings between the "xx" markers as groups? Say by writing them to the console as: cc dd,ee,ff gg ...
What are the drawbacks of linq in general. ...
Hello Everyone I am programming space invaders for practise ;-) and works quite well but I have a problem with my invaders returning fire. All invaders are stored in a list and I use linq to group those invaders by their X-location so I can access a group randomly and take the invader that is at the bottom of that column to shoot back....
Hello, I have multiple linq queries for searching a database of information based on a single specific piece of criteria per query. e.g. by ID or by Name etc. Currently, the user can search by use of only one query method. The problem is that I want the user to be able to search using multiple criteria, without having to write new quer...
Here's another one of these LinqToSQL questions where I'm sure I must have missed the boat somewhere, because the behavior of the O/R Designer is very puzzling to me... I have a base class for my LinqToSQL tables, which I called LinqedTable. I've successfully used reflection to get hold of all the properties of the descendant classes a...
I am new to SubSonic and Linq Stuff and I am trying a figure out the shortest and optimal way of retrieving a single record. What other way is quicker and requires less code to write than this to get a single record? User user2 = DB.Select().From(User.Schema) .Where(User.PasswordColumn).IsEqualTo(password) .And(User.SINumberColumn).IsE...
SingleOrDefault returns null, but what if I want to assign values to represent the object that wasnt found? ...
Hi everyone! Is it possible to make LinQ to SQL read and understand a pure SQL query sucha as "SELECT * from myTable"?? My boss asked me to write directly to database the pure SQL querys in a certain table and this table will have a field named "typeOfSelect", for example. And, in my application, I will have to read this field "typeO...
How can I write a console application that prompts me and lets me enter LINQ expressions and it will spit out the results of that LINQ query? What would be the easiest way to parse/evaluate a incoming string as a LINQ expression? ...
I would like to select only few columns from a certain (Blobs) table. I have fields like: Id, RowVersion, Size, Signature, Blob, and I want to select only first four. I do it like this: (---> is an error place) public List<BlobDetails> GetAllBlobsNames() { RichTekstModelDataContext dc = new RichTekstModelDataContext(); var ...
Hi guys, I refactored my foreach loop from this before: foreach (KeyValuePair[string, string] param in paramsList) { XmlElement mainNode = xmlDoc.CreateElement("parameter"); mainNode.SetAttribute("name", param.Key); mainNode.SetAttribute("value", param.Value); rootNode.AppendChild(mainNo...
I have a (C#) class called Hit with an ItemID (int) and a Score (int) property. I skip the rest of the details to keep it short. Now in my code, I have a huge List on which I need to do the following select (into a new List): I need to get the sum of all Hit.Score's for each individual Hit.ItemID, ordered by Score. So if I have the follo...
I would like to build an Expression that would equate to expected... Expression<Func<ReferencedEntity, bool>> expected = (ReferencedEntity referencedEntity) => foreignKeys.Contains(referencedEntity.Id); Expression<Func<ReferencedEntity, bool>> actual; foreignKeys type is a List<object> Here is what I have so far and I think it would ...
I recently need to build a Expression tree so I wrote a Test method like so... /// <summary> /// /// </summary> [TestMethod()] [DeploymentItem("WATrust.Shared.Infrastructure.dll")] public void BuildForeignKeysContainsPredicate_shoud_build_contains_predicate() { RemoteEntityRefLoader_Accessor<ReferencedEntity> target = CreateRe...
I have the following three tables: With LinqToSql I would like to retreive a list of InventoryItems where (pointsName="Level" AND pointsValue <= maxStoreLevel) AND pointsName="Buy Price" and Note that maxStoreLevel is an Integer and it is the value of the points row that has pointsName = "Level". Since you can't use a where inside...
Suppose I have 2 enumerations that I know have the same number of elements and each element "corresponds" with the identically placed element in the other enumeration. Is there a way to process these 2 enumerations simultaneously so that I have access to the corresponding elements of each enumeration at the same time? Using a theoretic...
I have a list<> of an "region" class with two variables, "startLocation" and "endLocation". I'd like to combine those two into a new sorted 2 dimensional array where its just Location and an integer representing whether its start or an end. For example, if the list has three region objects with [Region 1] : startLocation = 5, endLocati...
Say I have a linq query select r in db.Roles where r.RoleName DOES NOT contain ("Administrator") select r; It is the does not contain part that has me confused. I realize I can do that .Contains call but how do you do the opposite? Thanks! Update: I found the Exclude method and here is how I used it: var role = (from r in db.Roles...
I got a list of RegionGroup objects with two properties: an int "number" and a list<> of "Regions". I need to output a distribution of number of Region objects combined for each number. For example, given: [Region 1] - number: 1 - list<> has 5 members [Region 2] - number: 3 - list<> has 2 members [Region 3] - number: 4 - list<> has 9...