Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Add your own checks prior to invoking the supplied delegate. This way, you can check all of the requirements are met prior to invoking and the checking is done in one place (instead of duplicated in each implementation).</p> <pre><code>public void DoStuff(List&lt;int&gt; list) { CheckPreconditions(list); double ans = Calculate(list); } private void CheckPreconditions(List&lt;int&gt; list) { if(list == null) // throw ... if(list.Length == 0) // throw ... if(Length &lt; list.Count) throw ArgumentException("list", "list must have blah blah blah to satisfy requirements"); } </code></pre> <p>This is similar to the <a href="http://en.wikipedia.org/wiki/Template_method_pattern" rel="nofollow noreferrer">template method pattern</a> except instead of using inheritance, you're delegating to a user-supplied function :)</p> <p>Also, if you make Calculate a field instead of a public property, you can force it to be executed through the DoStuff method, so the checks will always be carried out.</p> <p>Something like:</p> <pre><code>class Test { public int Length{ get; set; } private Func&lt;List&lt;int&gt;, double&gt; m_calculate; // Inject into ctor public Test(Func&lt;List&lt;int&gt;, double&gt; calculate) { if(calculate == null) throw new ArgumentNullException("calculate"); m_calculate = calculate; } // all access to Calculate is now through this method public void DoStuff(List&lt;int&gt; list) { CheckPreconditions(list); double ans = m_calculate(list); } } </code></pre> <p>This would be a good fit if Calculate is only ever set once.</p>
    singulars
    1. This table or related slice is empty.
    1. PORuntime check for a Func delegate
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USMark Simpson
    1. USMark Simpson
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PORuntime check for a Func delegate
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COExcellent. I did think about executing the checks before calling the Func delegate, but missed about making it a private field so that the checks can always happen. Thanks much.
      singulars
      1. PO
      1. USSamik R
 

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