In Firebase, we have four methods available to write a data into the Firebase database:
| set( ) | Write or replace data to a defined path, like messages/tickets/<uid>. |
| update( ) | Update to specific children of node without replacing the other child nodes. We can also use the update method to update the data into multiple locations. |
| push( ) | To add a list of data in the database, we can use the push() method; it generates a unique ID every time when it calls, such as helpdesk/tickets/<unique-user-id>/<unique-ticket-id>. |
| transaction( ) | We can use this method when we are working with complex data that can be corrupted by concurrent updates such as incremental counters. |
Now, let's take a look at how data is structured in our helpdesk application:
{
"tickets": {
"-L4L1BLYiU-UQdE6lKA_": {
"comments": "Need extra 4GB RAM in my system"
"date": "Fri Feb 02 2018 15:51:10 GMT+0530 (India Standa..."
"department": "IT"
"email": "[email protected]"
"issueType": "Hardware Request"
"status": "progress"
},
"-L4K01hUSDzPXTIXY9oU": {
"comments": "Need extra 4GB RAM in my system"
"date": "Fri Feb 02 2018 15:51:10 GMT+0530 (India Standa..."
"department": "IT"
"email": "[email protected]"
"issueType": "Hardware Request"
"status": "progress"
}
}
}
Now, let's take an example of the preceding data structure and use the set() method to store the data with autoincrementing integer:
{
"tickets": {
"0": {
"comments": "Need extra 4GB RAM in my system"
"date": "Fri Feb 02 2018 15:51:10 GMT+0530 (India Standa..."
"department": "IT"
"email": "[email protected]"
"issueType": "Hardware Request"
"status": "progress"
},
"1": {
"comments": "Need extra 4GB RAM in my system"
"date": "Fri Feb 02 2018 15:51:10 GMT+0530 (India Standa..."
"department": "IT"
"email": "[email protected]"
"issueType": "Hardware Request"
"status": "progress"
}
}
}
Now if you see the preceding data structure, new tickets will be stored as /tickets/1. This will work if only a single user were adding tickets, but in our application, many users can add tickets at the same time. If two employees write to /tickets/2 simultaneously, then one of the tickets will be deleted by the other. So this will not be recommended practices and always recommend to use the push() method to generate a unique ID (refer to the preceding data structure) when you are working with list of data.