Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The <code>using</code> statement</p> <pre><code>using(var disposableObject = new object_that_implements_IDisposable()) { ... } </code></pre> <p>is syntactic sugar for code similar to following:</p> <pre><code>var disposableObject = new object_that_implements_IDisposable() try { ... } finally { if(disposableObject != null) { ((IDisposable)your_object).Dispose(); } } </code></pre> <p>This is <strong>only</strong> applicable for classes that implement IDisposable. It is helpful for cleaning up code where you have objects that take, for example, system resources (file handles, database connections, sockets, etc.) that need to be cleaned up after you are done to free the resource for the rest of the system.</p> <p>In theory, you could leave out the <code>.Dispose()</code> call, but then you would have to wait for the Garbage Collector to free the kept resources. The GC is awesome at knowing when to free objects to reclaim their memory usage, but it has <em>no idea</em> that it needs to free objects to have them give up other system resources. Thus, these critical resources might not be given up until after the GC decides it needs the memory used by the owner. Thus, you definitely want to dispose of your objects when you are done with them (if they are disposable)!</p> <p>As to why you'd use <code>using</code> over <code>try</code>/<code>finally</code>, it is purely a coder's preference. I prefer <code>using</code> because you can cascade them:</p> <pre><code>using(var a = new class()) using(var b = new class()) using(var c = new class()) using(var d = new class()) { ... } </code></pre> <p>You'd need quite a few more lines of code to do that with <code>try</code>/<code>finally</code>.</p> <p><code>using</code> has additional advantages as well. For example, whereas calling <code>x.Dispose</code> directly might throw a <code>NullReferenceException</code> if <code>x</code> is null, <code>using(x)</code> will not.</p> <p>See also:</p> <ul> <li><a href="http://blogs.msdn.com/b/shawnfa/archive/2004/03/29/101466.aspx" rel="nofollow noreferrer">http://blogs.msdn.com/b/shawnfa/archive/2004/03/29/101466.aspx</a></li> <li><a href="https://stackoverflow.com/questions/614959/using-the-using-statment-in-c">Using the using statment in c#</a></li> <li><a href="https://stackoverflow.com/questions/212198/what-is-the-c-using-block-and-why-should-i-use-it">What is the C# Using block and why should I use it?</a></li> <li><a href="http://msdn.microsoft.com/en-us/library/yh598w02%28VS.80%29.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/yh598w02%28VS.80%29.aspx</a></li> </ul>
    singulars
    1. This table or related slice is empty.
    1. POWhat does Using(.....){...} mean
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USDavid Pfeffer
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POWhat does Using(.....){...} mean
      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. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThe key is "you would have to wait for the Garbage Collector to free the kept resources." +1
      singulars
      1. PO
      1. USEugene Yokota
    2. COWhen leaving a **using** block, IDisposable.Dispose will be called. This may be different than your object's defined Dispose method if you have also defined IDisposable.Dispose explicitly.
      singulars
      1. PO
      1. USKevin Kibler
    3. COThanks for edit fixing placement of declaration and initialization of variable before the try. Removed my comment pointing out the flaw.
      singulars
      1. PO
      1. USGBegen
 

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