Writing Data Access Layer in C# for MongoDB

As discussed from our previous post, MongoDB is pretty good if we can work it in int's unique way. So, to do all of the work, we need to have a propert DB layer. Let's first look at how we can connect and then do a sample select.

 var client = new MongoClient("mongodb://localhost:27017");  
 mongoDatabase = client.GetDatabase("TemplateManager");  
 public List<T> Select<T>(string TableName, string SelectColumnName, BsonValue WhereValue)  
     {  
       var collection = mongoDatabase.GetCollection<T>(TableName);  
       var filter = Builders<T>.Filter.Eq(SelectColumnName, WhereValue);  
       return collection.Find(filter).ToList();  
     }    

Using above code, you can connect to the locally installed DB server get a list of records which can be converted into a list of entity.

Lets see how this is used.

 List<Person> personList = new bllPerson().Select();  

The Person is an entity which we use in the collection. The bllPerson is a class that handles DB calls. So it gets all the people saved under Person collection in the Database.

Try it and next time lets talk about Updated and Delete method.

Happy coding.

Using MongoDB for your .Net applications - Data Access (Layer)

Hopefully you might have worked on MongoDB or probably not. Anyway, MongoDB can be downloaded https://www.mongodb.com/download-center/community here. It's the community version and free version. Install and run the server. It runs on localhost:27017.

If you want to know more about what is MongoDB, visit here https://www.mongodb.com/what-is-mongodb

When you download the server and install, you can easily do all the CRUD operations. for that you need to install the MongoDB nuget package. Those have the necessary dlls to perform database actions. following are the packages you need to install.

Once you have it, you can reference the namespaces.

So, you now you are ready to write your own codes to deal with MongoDB. For example, you can think of the following code.

This is how you can get this to use in your front end.

try to understand the basics here. documentation of MongoDB is here (https://developer.mongodb.com/learn?languages=C%23)

Next time, lets see how we can write our own Data Access Layer.

Until that, happy coding.

MS Sql Server - Alternative to Cursor

Hello Friends,

If you are working with MS SQL Server, you may familier with Cursor which we use to loop through a recordset. But as everyone knows, cursors are expensive. They consume more memory and also take more time.

So lets discuss how to avoid cursors but how to loop as we use a cursor.

Create a temp table.

 create table #ttProduct (  
      [id] int identity(1,1) NOT NULL,  
      [idProduct] inIdentifier not null,       
      [idCategory] inIdentifier not null, ...etc  

and here we get selected records into the temp table.

 insert #ttProduct(  
 [idProduct],   
 [idCategory],   
 [lbCategory],  
 .  
 .  
 )  
 select   
      cp.idProduct,  
      po.idCategory,  
      cat.ShortName AS 'lbCategory',  
 .  
 .  

And now let's see how it is done.

 while exists (select * from #ttProduct)  
           begin  
                select top 1 @recordId = id, @idProduct=idProduct  
                from #ttProduct  
                order by id asc  
                --select * from #ttProduct where id = @recordId  
                -- Do something with your TableID  
                delete #ttProduct  
                where id = @recordId  
           end  
 drop table #ttProduct  

it is basically a while loop and each iteration we delete the top record once processed. So it will ultimately run out from records. End of everything, drop the tempory table too.

Hope you have got your idea.

c# method to return dynamic types

This is a simple method that return dynamic types based on what it recieves from the parameter.

 private dynamic GetValue<T>(object value, bool toString)  
     {  
       Type type = typeof(T);  
       if (value == null || (value != null && string.IsNullOrEmpty(value.ToString())))  
       {  
         if (toString)  
           return string.Empty;  
         else  
           return null;  
       }  
       else  
       {  
         if (toString)  
           return value.ToString();  
         else  
           return Convert.ChangeType(value, type);  
       }  
     }  

value : the value you want to get
toString : whether the return type needs to be as a string.

example,

 item.EXT_PRODUCT_ID = this.GetValue<int?>(p.idProduct, true);  

The value we pass is

p.idProduct

and it is a nullable integer. Also we set toString as true. so the return value is :
"466565" or empty string.

Instead of checking null everytime, we can use this method.

Happy coding.

Multithreading - passing parameters

    When you need to write multithreading application, you might need to pass parameters to the method that is executed by another thread. Sometimes, assigining the value to a variable and access it from the method works but what if it's countless threads that access the same method. 

You can directly pass the values to the parameter. Look at the below code.

This is the method that needs to be executed by another thread. (Actually a loop of threads). This is how it can be done.

k.Key is the keyword and v is the url.

This way you can pass parameters and will not be effected to any thread.

Happy coding..

Implementing PIGNOSE Calendar in your webpage

PIGNOSE Calendar is beautiful and eidetic jQuery date picker plguin. It is easy to setup too. Lets see how it s done step by step.

You can download it from here.
https://github.com/KennethanCeyer/pg-calendar

The calendar looks like below when it is implemented.

Lets see how it is done.

1. Add a textbox to work as the date controller

 <input class="datePicker" type="text" id="dateFrom" name="dateFrom" readonly="readonly" placeholder="Date : du" data-input-style="box" data-label-style="stacked" value="">  

You can see that the class of the input is datePicker

2. In your JS file, write the following.

   $('.datePicker').each(function () {  
     $(this).on('focus', function () {  
       //console.log($(this).pignoseCalendar().settings)  
       $(this).pignoseCalendar({  
         // en, ko, fr, ch, de, jp, pt, fr  
         lang: 'fr',  
         // You can change auto initialized date at first.  
         date: moment(),  
         // light, dark  
         theme: 'light',  
         // date format  
         format: 'DD/MM/YYYY',  
         // CSS class array  
         classOnDays: [],  
         // array of enabled dates  
         enabledDates: [],  
         // disabled dates  
         disabledDates: [],  
         // You can disable by using a weekday number array (This is a sequential number start from 0 [sunday]).  
         disabledWeekdays: [],  
         // This option is advanced way to using disable settings, You can give multiple disabled range by double array date string by formatted to 'YYYY-MM-DD'.  
         disabledRanges: [],  
         // Set and array of events to pin on calendar.   
         // Each event is an object that must contain a date string formatted to 'YYYY-MM-DD' and class key that belong to classOnEvents dictionary indicating its color on calendar.   
         // Events with not color class suitable are all pin with #5c6270.   
         // Issues may arise when the number of color class increase, this could break the calendar cell.  
         schedules: [],  
         // Set a dictionary with class 'key' and color code 'value' used for pin events class by date.  
         scheduleOptions: {  
           colors: {}  
         },  
         // Your first day of week (0: Sunday ~ 6: Saturday).  
         week: 1,  
         // If you set true this option, You can use multiple range picker by one click on your Calendar.  
         pickWeeks: false,  
         // You can turn on/off initialized date by this option.  
         initialize: true,  
         // enable multiple date selection  
         multiple: false,  
         // use toggle in the calendar  
         toggle: false,  
         // reverse mode  
         reverse: false,  
         // display calendar as modal  
         modal: false,  
         // add button controller for confirm by user  
         buttons: true,  
         // minimum disable date range by 'YYYY-MM-DD' formatted string  
         minDate: moment().subtract(10, 'years').endOf('year'),  
         // maximum disable date range by 'YYYY-MM-DD' formatted string  
         maxDate: moment(),  
         // called when you select a date on calendar (date click).  
         select: disabledValidation,  
         // If you set true this option, You can pass the check of disabled dates when multiple mode enabled.  
         selectOver: true,  
         // called when you apply a date on calendar. (OK button click).  
         apply: disabledValidation,  
         // called when you apply a date on calendar. (OK button click).  
         click: disabledValidation  
       });  
     });  
   });  

Note that, if you have a calendar icon, add a css class and have the same as above. then both textbox and calendar will work with the control.

Finally make sure you have added all the necessary files in SRC folder and linked the JQuery as it is required to the page.

The result will be as below. (The language is set as French and you can easily change it to any language that it supports. )

Hope this calenar will give your website a nice look and feel.

Happy coding..

Encrypting Emails using JQuery & CryptoJS

If you have a web page that shows contacts with email addresses, it is advised to use any mechanism that the email is hidden from robots or crawlers so that it can't be collected without any permission. Your customer will certainly like to see this kind of feature implemented in his website too. Lets see how we can get this done. This time, I am using fairly simple way as anyone can easily implement this on any existing website. This doesn't require any changes to your source code but to have some simple javascripts.

You will have to reference the CryptoJS library here.

https://github.com/ihsmarkitosi/CryptoJS-v3.1.2

Next, refer it to your page. In this case, I have downloaded the file and hosted locally.

<script src="/javascript/aes.js"></script>

Now, lets imagine you have a html code like this,

It shows the email address and if you see the source of the page, it's easy to capture. so what we need is to encrypt these emails. we can do this in many ways. one is to encrypt it in DB level. Other is to encrypt in you business layer or in code file.

The last one is to use the java-script. NOTE that this is not for any security and the idea is to hide the email addresses only. 

So, lets move to the javascript file.

For select controls, we can encrypt the options as per below. You need JQuery for this.

 $("#ttMailActorToSelect > option").each(function () {  
     var attr = CryptoJS.AES.encrypt($(this).attr('ttmailactorto'), "Dars1akaI@om");  
     $(this).attr("ttmailactorto", attr);  
 });  

You can replace this Dars1akaI@om on your own 

And for radio buttons, you can use the following. I used a custom attribute ttmailactorcc.

 $(':radio').each(function () {  
     if ($(this).attr("ttmailactorcc") && $(this).attr("ttmailactorcc").length > 0) {  
       //alert($(this).attr("ttmailactorcc"));  
       var attr = CryptoJS.AES.encrypt($(this).attr('ttmailactorcc'), "Dars1akaI@om");  
       $(this).attr("ttmailactorcc", attr);  
     }  
 });  

Note that you have to do this inside document ready state. The result will look like below.

When you need to access these values, you can decrypt it as below,

 var ttMailActorToSelectedValue = $('#ttMailActorToSelect option:selected').attr('ttmailactorto');        
 var ttMailActorTo = CryptoJS.AES.decrypt(ttMailActorToSelectedValue, "Dars1akaI@om").toString(CryptoJS.enc.Utf8);              

Try this. Hope this will help you.