Archives by Tag 'LINQ'
How does LINQ to SQL concurrency detect conflicts
LINQ to SQL utlises optimistic concurrency control (OCC) to determine the conflicts. OCC compares the loaded record to existing record before performing an update operation on the row so that the underlying conflicts could be detected. The followings are steps to replicate the scenario, Table Fruit Id Name UnitPrice Description 1 Apple 2.5 very long [...]
LINQ InsertOnSubmit, DeleteOnSubmit and SubmitChanges not working
I had the same problem with SQLExpress database file. In one word, I looked at the records from the wrong database. There were actually two versions of the database file. The mdf file gets copied over to bin\debug\data folder e.g. bin\debug\data\test.mdf after compilation, but I verify the data against the one within solution. This likely [...]
Separator Delimited ToString for Array, List, Dictionary, Generic IEnumerable
Often programmers want to convert an array into one string with for example comma delimited. Traditionally, in C#, it can be achieved by int[] array = {1,2,3}; string delimited = string.Join(”,”, array); Console.WriteLine(delimited ) // output: "1,2,3" However, string.Join does not apply to any generic IEnumerable object. It would be so much easier if [...]
LINQ: Combine elements in nested collection
Simple script to combine elements within nested list (A list’s elements are lists) static void Main(string[] args) { // initialize a list object with List<string> elements List<List<string>> nestedList = new List<List<string>>(); // add an element to the main list object nestedList.Add(new List() { “a”, “b”, “c” }); // add another [...]