How to compare tow list of object ?

Question

User632428103 posted

Hello all,

imagine this scenario, i have a device when the user connect i call a web service and get some resutl

IEnumerable<someObject>

i insert all content into the database all works fine.

Now, we add in the back end some new object, modify, update, delete and so on ...

user make a log off, when user connect again i call again the web service and get the new IEnumerable<someObject>

I would like to know i can make a find the DIFFERENCE between these two objects ?

because i need to insert some news, and delete some old ...

I've try that, but that's work only if i have some new object IN the wsDatas

//a: get datas from db
                    var dbDatas = from db in xxx.SelectAll<someObject(true)
                                  select new { db.ProfileCode, db.ProductCode, db.CategoryCode, db.OptionCode };

//b: get data from web service
                    var wsDatas = from ws in datas
                                  select new { ws.ProfileCode, ws.ProductCode, ws.CategoryCode, ws.OptionCode };

                    // compare
                    var newDatas = wsDatas.Except(dbDatas);

of course, i can delete all datas and replace all but i would like to know how to find difference between two list of objects

thanks in advance

Answer 1

User-832373396 posted

<g class="gr_ gr_15 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-ins replaceWithoutSep" id="15" data-gr-id="15">Hi</g> <g class="gr_ gr_5 gr-alert gr_spell gr_inline_cards gr_run_anim ContextualSpelling ins-del multiReplace" id="5" data-gr-id="5">jimmy</g>,

Sir, If you only want to compare two <g class="gr_ gr_55 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar multiReplace" id="55" data-gr-id="55">list</g> of object.

.Except(

This is the way.

and in fact, it is very strange with your logic.

• 1 What represents the old and what represents the new?
• 2 if you already added or modified to the database, then when you get the data from web service,  it should be the updated data.

So they are same, no difference;

• 3 maybe you could show us the data for help you better;

insert some news, and delete some old ...

• 4 is it means that to insert some news into the database?

With regards, Angelina Jolie