SharePoint 2013 Business Data Connectivity Services questions

You first question seems to indicate a misunderstanding about SharePoint. A SharePoint list is found in a SQL database, but you don't need BDC to get to data in a SharePoint list.

Are you referring to something else besides and just calling it a SharePoint list?

let me reframe my questions.

My objective is fetched data from ASP.NET application and that is using MS SQL database.

Now I want that data to be accessed using SharePoint BDC service and have following questions.

1. How to edit data in SharePoint list once it is fetched from SQL database?
 2. Later can we add more fields to SharePoint list if needed?
 3. How user permission will be remapped or updated? to ensure only user who is authorized is updating the SharePoint list?
 4. Can we have two sync meaning if someone update the data on SQL using another ASP.net application and someone using SharePoint list? will both changes be seen on ASP.Net application as well SharePoint list?
 5. Can we have versioning enabled on SharePoint list which is created through BDC process?

Thanks for the reframe, it makes more sense now:

When you connect to a SQL database from SharePoint using Business Connectivity Service (BCS), you can create an external content type for that data. That content type can be used in a SharePoint list just as a normal content type. When you create the connection, via SharePoint designer, you determine the type of access be it read only, write access etc...

SharePoint list permissions will apply, so if you have the connection set up as a full read \ write connection, a user with read only access to the list will not be able to write to the list, including the external content type (the SQL database.)

As far as changes being seen, yes they will be seen, however the user using the ASP.net will not see any changes to the SharePoint list that are not connected to the SQL database using the external content type. That means, that is the SharePoint list has multiple content types putting various columns in use, the columns that are not a part of the external content type will not write back to the SQL data base. This could become a problem depending upon what specifically you are trying to do.

As far as versioning, standard list item versioning can be enabled, but it would not be linked to any type of versioning on the SQL database.

Honestly, this approach you are considering seems that it is going to lead to big problems. You have a challenge of keeping two separate databases in sync, (consider unique ID's for example). If users are allowed write access in both SharePoint and your ASP.Net application there could be data integrity problems, not to mention possible conflicts of data that needs to be resolved, a difficult process to code for. If possible, decide on one data source and design around that and not attempt to keep two data sources in-sync that have such different purpose and design. Just my two cents worth...

Good luck...

Thank you Brother!!

So I think the best would be not write data back to that SQL database from SharePoint, instead just create new column in SharePoint and use SharePoint database and then only update those columns.

Could you please confirm if this is possible.

Thank you very much SneekCo

I appreciate all your help. Excellent Job!!

Thanks, glad I could help and good luck!