I am working on automating a license process fro my organization. With asp.net I am able to create a WebPart that submits data to a database in SQL. Now what I want to do is to initiate the approval workflow with that data. My data has a lot of attachments(10) and I realized I cannot pull these into a SharePoint list to initiate the workflow from there. Which steps can I take to achieve this without using Windows Workflow
It's possible you could create a site workflow, and start it programatically. Sample code to stat it programatically is here. However, I'd recommend not starting new development using SharePoint designer, especially when SharePoint is not really part of the solution. The big reason is that SPD 2013 is the final version of the product. MS is not coming out with a new version. Instead, I'd suggest looking into Flow, which is a cloud-based workflow tool from MS that can connect to on-prem sources, including SQL. Alternatively, look into Azure Logic Apps, which provides a bit more flexibility for developers. Or, since you're in .net already, just create your own approval page in .net and send out emails when appropriate. (If the only thing you need is the approval process, adding in SPD or Flow seems like a lot of extra work, IMO).