Question

Normally I use stored procedures / work in SQL so apologies if I get the terminology slightly off here..

I have a database, with 3 seperate tables, and I need to search multiple fields in each of the 3 tables.

Im sure that I am not doing this the mose effective way, initially I am trying to do it in simple seteps to understand it.

I have the following;

    var foo1 = entities.table1.Where(a => a.bodyText.Contains(searchString) || a.pageTitle.Contains(searchString));
    var foo2 = entities.table2.Where(b => b.newsArticle.Contains(searchString) || b.newsArticle.Contains(searchString));
    var foo3 = entities.table3.Where(c => c.ImageDescriptionContains(searchString));

I need to combine all these results into a single repeater for display.

At this point all 3 sets of data are in seperate, unique collections of anonymous data. So whats the best way of converting these into a single coherent bindable source?

I was thinking of itereating through each list in turn, pulling out the fields I need to display and putting them in a new class, then binding a lsit of these classes to the repeater.

But it all seems a bit clunky to me.

Is there a way of doing the search across all 3 tables in one go, and returning just the fields I need from each table, with a common name (i.e. in SQL I could write

    select b.newsArticle as myText, 

or

    select newsArticle, '' 

to return the news article and an empty string).

Answer 1

This would combine:

var foos = foo1.ToList();
foos.AddRange(foo2);
foos.AddRange(foo3);

To get just what you want:

var myExtractedValues = foos.Select(x => new { 
         Article = !string.IsNullOrEmpty(x.newsArticle)) 
                           ? x.newsArticle 
                           : string.Empty});

I have used an anonymous type here but you could swap the new {} with a type of your own.

I reverse the operator on the IsNullOrEmpty but that is just a personal preference (I prefer how is reads.)