SOAP UI vs POSTMAN

Sometimes SOAP UI displays objects also as arrays for JSON message, better to use Postman tool from google apps which is the best app for JSON or REST API testing.

Swagger doesn't support decimal

As of version 7.10.0 using node.js the swagger doesn't support the decimal however it supports the number of type float of 32 bit, double of 64 bit but not decimal of 128 bit.

So you can declare as a field of type decimal as below..

  "amount" : {

          "type" : "number"

Then cast it to decimal like CAST(amount AS DECIMAL);