Question

I have a table:

Id  Catg 1   cat01 2   cat01 3   cat01 1   cat02 2   cat02 

now I want to detect number of occurance of catg01 and catg02,like in this ex, catg01 is 3 times and catg02 is 2 times,I want to count that through LINQ/ simple db query. Pls note: cant use Where clause and hardcode Catg01/catg 02,as there can n number of category.Is it possible to detect? if yes then pls help.

Answer 1

Select Catg, Count(*) From TableName Group By CatG 

For the LINQ Version. Imagine a Class

    class Table     {         public int ID { get; set; }         public string CatG { get; set; }     }  

Then if you had a list of that class, you could query it as follows

List<Table> y = new List<Table>();  y.Add(new Table() { ID = 1, CatG = 'a' }); y.Add(new Table() { ID = 2, CatG = 'a' }); y.Add(new Table() { ID = 3, CatG = 'a' }); y.Add(new Table() { ID = 4, CatG = 'b' }); y.Add(new Table() { ID = 5, CatG = 'b' });   var query = y.GroupBy(table => table.CatG);  // Iterate over each IGrouping in the collection. foreach (var item in query) {     Console.WriteLine('CatG: {0} Number of Items: {1}', item.Key, item.Count()); }