About MVC view and DataBinding from SQL

Question

hello, I have view with textbox and I have given @Value to that textbox as 15 by default. Please refer textbox below : @Html.TextBoxFor(Model => Model.quantity, new { @id = "txtquantity", @type = "number", @class = "form-control", @Value = "15" }) I am able to save that or any other value in SQL DB. But when I edit that textbox, it should bind the value which is saved in a database, but still it binds that by default "15" value, even in db the value is saved different. Anything can be done to make this work? Thank you in advance!

Kiran Mohanty · Answer

In your approach, as while rendering view, compiler always finds 15 as the value you are trying to bind (no matter whether you have any saved data or not. So what you can do is, bind "15" as default value in model constructor like public class DataViewModel { public int Quantity { get ; set ;} public DataViewModel (){ this .Quantity = 15; } }

Sachin Singh · Answer

if you want to delete records which is foreign key then make cascade delete OFF. open SSMS-->Table--->relationship--->cascade delete off

Satya Karki · Answer

Hi, you can bind textbox value from Model. @Html.TextBoxFor( Model = > Model.quantity, new { @ id = "txtquantity" , @ type = "number" , @ class = "form-control" , @ Value = Model .Quantity })

Rijwan Ansari · Answer

Use default value in your model and bind model in textbox as shown. Update model default value [System.ComponentModel.DefaultValue(15)] public int Quantity{ get ; set ; } then use code binding @Html.TextBoxFor(Model => Model.quantity, new { @id = "txtquantity" , @type = "number" , @ class = "form-control" , @Value = Model.Quantity }) Try this and let me know if it works. Regards Rijwan

Sachin Singh · Answer

so , if you have already given the default value then how do you suppose it to update itself? it will always be the default value untill you will not make it dynamic. you need it to bind with model value otherwise how the value field will be update automatically. @value=model.Quantity so that it will change each time.

Sachin Singh · Answer

Please go through article https://www.sharpencode.com/article/MVC/modals-and-strongly-typed-views The summary is , use strongly typed model and pass the values from controller to view at edit time. public ActionResult Edit( int Id) { var product= context.Products.where(x=>x.productId==Id).single(); return view(product); } in the view, now bind values from model and it will work as expected. @model MyAppName.Models.Product @Html.TextBoxFor(Model => Model.quantity, new { @id = "txtquantity" , @type = "number" , @ class = "form-control" , @Value = Model.Quantity })

Guest User · Answer

Also, just a question about SQL database, I want to delete records in my table, but the primary id of my table is a foreign key in another table. So I am not able to delete records from my table Any simple way to work on this, so I can delete records from that table? Thak you

Guest User · Answer

Thank you, everyone, for your replies and valuable time in this. The issue has been fixed.

Sachin Singh · Answer

your question is really confusing, you are saying , you want to show 15 so that user don't need to enter anything or they could change if they want. again you are saying you want to bind from database. what do you actually want 15 or value from database? you can't get both at the sametime.

Guest User · Answer

I mean I have to show @Value="15" on "Add Product" Screen, so user don't have to enter anything in that textbox, it will save that 15 value or he can change that value also. But when user edit that product, it still bind that 15 , even if database has different value stored So is there any way I can achieve that. Thank You!

Guest User · Answer

hello Sachin, Thank you for your reply. The solution you gave is right, but this is not what i'm looking for. My edit query is working and it getting all the fields in query properly, it is just not binding to the textbox, because i have given my textbox @Value="1" by default in view. it should bind the value which I am getting from my edit query

Guest User · Answer

hey kiran, i have tried and this is not working, it binds value from db, but on page load it binds textbox value as blank, it should be 15