Need Design Suggestions

Question

Hi All, 
 I need some design suggestions on my requirement below . 
 I have a excel which has around 1000 rows and has 5 columns . All four columns are some labels and the last column has VALUE(Sample below) 
 My requirement is to upload this excel file and save into Appian DB but before i save this data i want to perform some validations on VALUE column let say : 
 1. first 5 rows should fall into tolerance band of 100-200 
 2. Next five rows should fall into tolerance band of 10-35 
 3. first 5 rows should sum upto 100 
 If values doesn't pass above validations then i need to tell user to re upload the excel with correct values .

Col 1 
 Col 2 
 VALUE

ABC 
 XYZ 
 200

ABC 
 XYZ 
 1290

ABC 
 XYZ 
 506

ABC 
 XYZ 
 6.88

ABC 
 XYZ 
 5.18

Thanks in advance

Dude · Answer

This you can achieve by providing the upload file interface component. 
 Reading the file in the process 
 Create an expression to select the number of rows 
 Keep the timer for delay if you want to delay the row writing. 
 Let me know the definition of tolerance band with respect to your explanation. Because its more relevant to resistors in electronics.

Mike Schmitt · Answer

I'm not personally an expert in Stored Procedures, so I can't speak to whether the method suggested by Stewart above would be easier or not. For me, though, it would be harder than simply handling the logic within Appian. 
 Here's a quick breakdown of my suggested design/process flow: 
 
 The user provides the Excel file on a SAIL form via a!fileUploadField() - this will include a validation that the uploaded file's extension is exactly ".xlsx". The user will click a button or submit link labelled "validate", which will submit from the form and run through a set of script tasks 
 The first script task will call an expression rule which first uses readExcelSheet() (found in the Excel Tools plug-in) to read the contents of the excel file and formats it into an array of your own custom-defined CDT type 
 The second script task will call a second expression rule that accepts the previously-defined CDT array as an input, and (assuming it's not blank, empty, or in some other rule-out exception state) validates the values based on the logic you've defined above. Appian expression rules can easily handle logic like your requirements (or even quite a bit more complicated) with some practice. The expression rule would return "true" if the values pass your validation, and "false" otherwise. This would save into a PV i.e. "pv!isValidExcel". 
 If the validation value is "false", loop back to the form and pass the failed validation state into a Rule Input, which you use in order to display some validation text to the user. 
 If the validation passes, here is a design choice for you: you can:
 
 loop back to the form and show the user a friendly "valid data" message, followed by an additional submit button labelled i.e. "Save", which will let them submit and save the values to the database. The advantage of this method is visibility and also facilitates allowing the user to remove their original upload and provide a new version if they're unsatisfied with it for some other reason. They can also be required to provide other on-form details, etc.
 
 (This would be my personal preference, unless required otherwise by external factors such as customer preference etc).

continue straight to the Write to DB node(s) and then exit. This method would be most useful in cases where it's an assumption on the user's part that they will usually only need to perform a single step to upload/save a valid file, and the validation error will be a rare event and there isn't other on-form data that they'd be expected to provide. It's not as good for visibility but minimizes clicks (from 2 clicks to 1 click, anyway).

Regardless of the route taken above, the process would eventually write the validated CDT data to the database per your particular requirements. 
 
 A slightly simplified version of the process flow I'm thinking of is pictured here: