StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
8902658
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
5
CommunityOwnedDate
CreationDate
2012-01-17T22:33:22.177
FavoriteCount
0
LastActivityDate
2012-01-17T22:39:30.877
LastEditDate
2012-01-17T22:39:30.877
LastEditorUserId
390819
OwnerUserId
390819
ParentId
8901695
PostTypeId
2
Score
1
ViewCount
0
LastEditorDisplayName
text
Body
The fundamental difference between the two cases is that: <ul> <li>in the first case, LINQ2SQL translates the <code>Where</code> condition to SQL and passes it to the DB to do the actual filtering</li> <li>in the second case all records are retrieved from the database and the filtering is done on an in-memory list of objects</li> </ul> The result difference may for example be explained by a truncation which might take place in SQL if the <code>Datum</code> columns are defined as <code>date</code> instead of <code>datetime</code>. I managed to reproduce the problem like so: I have a table defined like this: <pre><code>CREATE TABLE [Event] ( [Id] int identity primary key, [EventDate] date ) </code></pre> I entered the following data in the table: <pre><code>Id EventDate -- --------- 1 1/17/2012 2 1/18/2012 </code></pre> In C#, my date limits are defined like so: <pre><code>var startDate = new DateTime(2012, 1, 17); var endDate = new DateTime(2012, 1, 18).AddMinutes(10); </code></pre> Having this set up, I now do: <pre><code>var events1 = dc.Events .Where(d => d.EventDate > startDate && d.EventDate < endDate) .ToList(); foreach (var @event in events1) Console.WriteLine(@event.EventDate); </code></pre> which returns only the first row (EventDate = 1/17/2012) And I do: <pre><code>var events2 = dc.Events.ToList(); foreach (var @event in events2 .Where(d => d.EventDate > startDate && d.EventDate < endDate)) Console.WriteLine(@event.EventDate); </code></pre> which displays both records. The difference is that in the first case, L2S translated the upper date limit from <code>datetime</code> to <code>date</code>, because that's how I defined the <code>[EventDate]</code> column. This loses the time part, and <code>'2012-01-18 00:10'</code> becomes <code>'2012-01-18'</code>. When comparing with '<' (strictly less than), of course the 2012-01-18 record is filtered out by SQL. In the other case I have the dates as they are in SQL, but this time they are filtered in-memory against the <code>endDate</code> value which is defined as a <code>DateTime</code>, thus holds time information and the 'strictly less than' condition becomes true.
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POLinq to SQL c#, Association - what could go wrong?
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USGolfWolf
UserOwnerUserId
1. USGolfWolf
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId

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.