Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>If you are looking for less lines you can replace the if/else with ternary operator:</p> <pre><code>query = SearchType == SearchType.And ? PredicateBuilder.True&lt;Job&gt;() : PredicateBuilder.False&lt;Job&gt;(); foreach (var predicate in predicates) { query = SearchType == SearchType.And ? query.And(predicate) : query.Or(predicate); } </code></pre> <p>for the <code>'and not' / 'or not'</code> part the <code>!</code> operator should do the trick.</p> <p><strong>PD:</strong> Did you test the <code>foreach</code> part is correctly setting the predicates?, as far as i remember you are building the expression that will be executed at later point in time, so you may have a literal reference just to the last set predicate in the final iteration, and that's why you must use a temp variable to save the value of each iteration.</p> <p><strong>EDIT:</strong> If you want to negate a expression programmatic, that's a tricky one, you can try something like:</p> <pre><code>internal static Expression&lt;Func&lt;Job, bool&gt;&gt; Description(string term, bool invert) { return NegateExp&lt;Func&lt;Job, bool&gt;&gt;(p =&gt; p.Description.Contains(term), invert); } </code></pre> <p>And the NegateExp method will be something like:</p> <pre><code>public static Expression&lt;TDelegate&gt; NegateExp&lt;TDelegate&gt;(Expression&lt;TDelegate&gt; expression, bool inverse) { if (inverse) { return Expression.Lambda&lt;TDelegate&gt;(Expression.Not(expression.Body), expression.Parameters); } return expression; } </code></pre> <p>You can take a look at this question for more examples <a href="https://stackoverflow.com/questions/2166591/is-there-any-way-to-negate-a-predicate">Is there any way to negate a Predicate?</a></p>
    singulars
    1. This table or related slice is empty.
    1. POLinq PredicateBuilder with conditional AND, OR and NOT filters
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USJOBG
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POLinq PredicateBuilder with conditional AND, OR and NOT filters
      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. COI've been profiling the generated SQL, and it all looks ok. Fair comment about using ternary operators although i'm more concerned about the duplication in my updated predicates.
      singulars
      1. PO
      1. USricheym
    2. COusing Expression.Not with a delegate should be usefull here. Added a little example above.
      singulars
      1. PO
      1. USJOBG
    3. COThat's an interesting one, will give it a try tomorrow. It also occurred to me that I could simply XOR the expression with the invert parameter - It works but it generates some pretty inefficient SQL.
      singulars
      1. PO
      1. USricheym
 

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