The last four blog posts have introduced you to working with a PouchDB database. You learned to modify documents one at time, in bulk, and learned to query the data within that database. In this fifth part of our ongoing series on PouchDB, you learn to use reduce queries to provide summary data such as the sum or average cost data, minimum and maximum, and how to calculate an average of cost data.
In the last three blog posts in this series, you created a PouchDB database and modified documents within it. You learned to search for documents within the database using allDocs() and find(). In this fourth part of our ongoing series on PouchDB, you learn to use map queries and the query() method.
In the last two blog posts, you have been introduced to the PouchDB NoSQL database. You learned to create a new database, modify documents within that database, and retrieve documents using the allDocs(). Now that you have inserted several documents into your PouchDB database, you might wish to retrieve documents based on data in fields other than the _id property. In this third part of our on-going blog posts on PouchDB, you learn to use the find() plug-in to perform queries on any property in your documents.
As more and more users interact with web applications on their mobile devices, it is becoming increasingly important for us to allow them to work offline. There are many cases where users need to work offline, such as on an airplane, in a remote location where there is no cellular access, or perhaps on board a large ship where Wi-Fi is not available. If you can store data local to your web application, the user can continue to work even without a connection.