title: Replace all occurences of a substring in a field in all documents in MongoDB
body: <p>I have a collection Brands, I have to replace the path ./assets/ to D:/data/db/images , I have multiple occurrences of this in multiple documents. How do I acheive this using a query ?</p>
  
  <p>Sample of each document </p>
  
  <pre><code>{"name":"Dell","images":["./assets/dell1.jpg","./assets/dell2.jpeg","./assets/dell3.jpg"],
               "captions":["Yours is here","Easy as dell","Uniquely you"],
               "logo":"./assets/dell4.png",
               "details":{"headOffice":"Bangalore","address":"No.12/1, Divyashree Green, Koramangala Inner Ring Rd, Domlur, Bengaluru - 560071",
               "phoneNumber":"(080) 28077000  ","website":"www.dell.com"}
               }
  </code></pre>