C#•4y ago

Help recquired please! I got stuck at using ui controls like dropdowns and radio buttons im .net cor

Hi, I got stuck in using ui such as Drop-down list and radio buttons for binding data from db and to push to database as well.

I am confused to pick some best way to do this. Does anyone point some resources or pdfs please?

Binto86•8/29/22, 2:49 PM

No resources, but i did something like this so i can maybe help

Binto86•8/29/22, 2:49 PM

What is your scenario exactly?

BBinto86 No resources, but i did something like this so i can maybe help

cnetworksOP•8/30/22, 3:59 PM

thank you
I hv drop down list in my mvc create view. Which gets dynamically binder from db

Now it's shows redundant values.
For ex if my table has 3 IT, 2 Admin, a Account items in Dept field, then my drop-down in view, fetches IT 3 times and Adm8n 2 times as it was in database.How to eliminate thus redundancy?

BTW, I just using one table in database.Thank in Advance

Binto86•8/30/22, 4:03 PM

So u have table something like this?

IT
2.IT
3.IT
4.Admin
5.Admin

Ccnetworks thank you I hv drop down list in my mvc create view. Which gets dynamically bi...

Binto86•8/30/22, 4:06 PM

I think you can just use on the db select

BBinto86 I think you can just use `SELECT DISTINCT` on the db select

cnetworksOP•8/30/22, 5:31 PM

yes.i am scaffolding by database first..Not write a single query.entity framework core does all this.

Is it I need to use a separate Department table in that same db?
like a Dept table with DeptId(pk), DeptName
along with main database table Employee fields( Id(pk), EmpName, DeptId(fk))

I tried this but while establishing fk,pk relation it spit error showing a message that two tables must have same number of fields.

Ccnetworks yes.i am scaffolding by database first..Not write a single query.entity framewor...

Binto86•8/30/22, 5:58 PM

Um ok im not sure what are you talking about in the second part? But if you are using ef you can just juse linq for the sorting and scree on the sql

BBinto86 Um ok im not sure what are you talking about in the second part? But if you are ...

cnetworksOP•8/30/22, 6:11 PM

I try to explain.

sorry just basic thing.i appreciate your spending of time.

Let's for instance, you are doing a sample crud in .net core mvc db first approach.

Name: Employee having three fields
1.Id(key)
2.EmpName
3.Department - drop-down
you have to show a list of department values dynamically retriieved from db and need to binded to this control.

Now, in Index view normally you list the all the data from table in a grid format.

In Create view,as you know you need to show the empty view with drop-down binded with values.

In Edit View, you need to retain the user's details and as you know let them to edit.Here too, I can retain the department choice in drop-down.i did that in my sample.

But when users enter various inputs (records) in create view with same department, I should not repeat any of the dept items binded to the drop down.
Fir that should I need to make a separate table for holding department values? like Employee table and dept table?

Sorry a bit long writeup thanks many!

Ccnetworks I try to explain. sorry just basic thing.i appreciate your spending of time. L...

Binto86•8/30/22, 6:48 PM

Ok i hope i understand you now

Binto86•8/30/22, 6:50 PM

So if you have a set of options the user needs to chose from, than you want a separet table to store the options and reference the id of given option from main table

BBinto86 So if you have a set of options the user needs to chose from, than you want a se...

cnetworksOP•8/31/22, 3:52 PM

okay for that I tried to create a Separate Department Table with 2 fields I'd and Name

and I tried to associate it's DepartmentId field to main table Employee as foreign key.
Butt error display that both table must hv equal number of fields for pk and foreign key relationship.

cnetworksOP•8/31/22, 3:53 PM

For example if the main table Employee has 6 fields,then do I need to have 6 fields in Dept table too?

Binto86•8/31/22, 3:53 PM

That seems weird

cnetworksOP•8/31/22, 3:54 PM

sorry for respond late.was off a little

Binto86•8/31/22, 3:54 PM

Where do u get this error from? Ef core?

cnetworksOP•8/31/22, 3:55 PM

no in sql server mgmt studio 2017

Binto86•8/31/22, 3:55 PM

Ok i never actualy set up forgein key, i always just specified it in query

cnetworksOP•8/31/22, 3:56 PM

but I tried creating the Dept table, after the ef scaffolding done and model generated.might be that could render error?

BBinto86 Ok i never actualy set up forgein key, i always just specified it in query

cnetworksOP•8/31/22, 3:56 PM

oh i see!

Binto86•8/31/22, 3:57 PM

I think you can do something like put the data in dropdown, than get the id of the selected option and write jt into the DepartmentId

Ccnetworks but I tried creating the Dept table, after the ef scaffolding done and model gen...

Binto86•8/31/22, 3:57 PM

I don't think i understand

cnetworksOP•8/31/22, 3:58 PM

may I know is it a good approach to create table in ql server mgmt studio or need to perform from visual studio?

sorry for basic doubt

Binto86•8/31/22, 3:58 PM

I always just do it in the managment studio

BBinto86 I don't think i understand

cnetworksOP•8/31/22, 4:03 PM

i meant that first I created Emoloyee table and made d project in visual studio, utilized the efcore and saffolded that single Employee database from sql server.
so far so good.project runs.perfect output.but I 9bserved during runtime my drop-down has values duplicates.like IT dept existed multiple times.

So I later created dept table in managementstudiowith just 2 fields and tried to have the keys on those fields..Then the error displayed in sql server management studio.

Binto86•8/31/22, 4:04 PM

Sure i knew all of that

BBinto86 I don't think i understand

Binto86•8/31/22, 4:04 PM

Well nvm don't wory sbout this

BBinto86 I think you can do something like put the data in dropdown, than get the id of t...

Binto86•8/31/22, 4:05 PM

What if you try this?

BBinto86 Sure i knew all of that

cnetworksOP•8/31/22, 4:06 PM

yes sure...

BBinto86 I think you can do something like put the data in dropdown, than get the id of t...

cnetworksOP•8/31/22, 4:08 PM

I think I don't understand what u are advising entirely? could you please elaborate a little?

Binto86•8/31/22, 4:08 PM

Ok sure

Binto86•8/31/22, 4:10 PM

So you take data from your Department table->you feed them to the dropdown->user selects one of the options->you take the option and get the id of the option -> you write that id to the DepartmentId field

BBinto86 So you take data from your Department table->you feed them to the dropdown->user...

cnetworksOP•8/31/22, 4:12 PM

oh I got it..you mean you need me to create one more field DeptId in the employee table? already I hv EmployeeId as one primary key in employee table

Ccnetworks oh I got it..you mean you need me to create one more field DeptId in the employe...

Binto86•8/31/22, 4:13 PM

Um no

Binto86•8/31/22, 4:14 PM

Bcs the forgein key doesn't really work, you can just screw on that and just do what i advised

Binto86•8/31/22, 4:14 PM

You would be writing into your already existing DepartmentId field

BBinto86 Bcs the forgein key doesn't really work, you can just screw on that and just do ...

cnetworksOP•8/31/22, 4:18 PM

haha but I only hv Deptment field in Emoloyee table table which is a nvarcharp showing depth....I don't have Dept Id like..with that Dept(name) only I m using in viewbag in action methods inside Controller to move around the Department Name.

Currently only EmployeeId is in my sql. I think u r advising to create separate table for Department with Id and name and suggest me to use them without creating fk right?

Ccnetworks haha but I only hv Deptment field in Emoloyee table table which is a nvarcharp s...

Binto86•8/31/22, 4:19 PM

Yes

Binto86•8/31/22, 4:19 PM

I thought you have that before, i guess i didint understand you corectly

BBinto86 Yes

cnetworksOP•8/31/22, 4:20 PM

oh in that case how you notify the ef that dept table is also a part of the solution without establishing pk and fk.sorry if it sounds dumb..

BBinto86 I thought you have that before, i guess i didint understand you corectly

cnetworksOP•8/31/22, 4:21 PM

no I got you...you understood my point before

Ccnetworks oh in that case how you notify the ef that dept table is also a part of the solu...

Binto86•8/31/22, 4:21 PM

Part of solution you mean like that this table exist in the db?

BBinto86 Part of solution you mean like that this table exist in the db?

cnetworksOP•8/31/22, 4:21 PM

yes yes

Binto86•8/31/22, 4:22 PM

Um tbh idk, but it should be pretty easy

Binto86•8/31/22, 4:22 PM

There is going to be some command for that

BBinto86 Um tbh idk, but it should be pretty easy

cnetworksOP•8/31/22, 4:22 PM

i see)

BBinto86 There is going to be some command for that

cnetworksOP•8/31/22, 4:22 PM

ok ok I will look into.

cnetworksOP•8/31/22, 4:23 PM

Thank u so much for supporting this far.

cnetworksOP•8/31/22, 4:24 PM

in db I can make the table inside.but in ef in visual studio, I don't know how to specify it.anyways I will refer,

cnetworksOP•8/31/22, 4:28 PM

i am glad friend and I really appreciate ur help.thank you so much once again-

Binto86•8/31/22, 4:34 PM

https://stackoverflow.com/questions/38739950/how-to-update-the-model-when-using-database-first-approach look here

Stack Overflow

How to update the model when using database first approach

I used EntityFramework Core database first to create model as illustrated in the EF Core documentation

But I don't know how to update the model when the database has been edit.