Databases
StackOverflow2013
Postsdbo
POIenumerable Extension method for dictionary array calls
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POIenumerable Extension method for dictionary array calls
    primarykey
    data
    text
    <p>Im trying to get an enumberable collection from a dictionary held array. Or should I say, I'm trying to write an extension method for my dictionary objects which store arrays to return an IEnumerable item when the result is null.</p> <p>Im using dictionarys to store array datasets (there are speed reasons for this), which I extract at certain search points. the extracted data is used in Linq queries, joins etc but I have problems when a data set doesnt exist.</p> <p>Returning an empty (0 count) row set would fix my problem. what I have so far is this (simplified code ofcourse)</p> <pre><code> public class Supplier { public string ID {get;set} public string Name {get;set} } private sups[] = new Supplier[10]; Dictionary&lt;int,Supplier[]&gt; dic = new Dictionary&lt;int, Supplier[]&gt;(); dic.Add(1,sups[]); public static IEnumerable&lt;Supplier&gt; TryGetValue&lt;Tkey&gt;(this IDictionary&lt;Tkey, Supplier[]&gt; source, Tkey ItemKey) { Supplier[] foundList; IEnumerable&lt;Supplier&gt; retVal; if (source.TryGetValue(ItemKey, out foundList)) { retVal = foundList.AsEnumerable(); } else { retVal = new Supplier[0].AsEnumerable(); } return retVal; } </code></pre> <p>// later in the code there is some thing like:</p> <pre><code>dic.TryGetValue(1).Count() //or a linq join from a in anothertable join d in dic.TryGetValue(1) on a.ID equals d.ID </code></pre> <p>What im trying to acheive is a generic extension method like below:</p> <pre><code>public static IEnumerable&lt;T&gt; TryGetValue&lt;Tkey,TValue&gt;(this IDictionary&lt;Tkey, TValue&gt; source, Tkey ItemKey) { // same code... // returning retVal = new T[0].AsEnumerable(); } </code></pre> <p>I keep getting close but never exactly there.... I would like to keep the extension method parameters simple. Its the passing of T which keeps catching me out.</p> <p>If anybody can help then please send me your feed back.</p> <p>many thanks in advance!</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAni
    1. USDubMan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POIenumerable Extension method for dictionary array calls
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POIenumerable Extension method for dictionary array calls
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO`Enumerable.Empty<T>()`
      singulars
      1. POIenumerable Extension method for dictionary array calls
      1. USWinston Smith
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload