PouchDB Replication
PouchDB Replication
- Replication means make a copy of a database. We can replicate either a CouchDB instance stored remotely or a PouchDB instance stored locally.
Syntax
PouchDB.replicate(source, target, [options])Replicating PouchDB (Local) to CouchDB
- Let's take a database named "sample_database" in PouchDB which have 3 documents doc1, doc2, and doc3, having following content.
{
"_id": "001",
"name": "Admin",
"age": "23",
"Designation": "Programmer",
"_rev": "1-a87843ccb443c46028a7704a82de00fc"
}
{
"_id": "002",
"name": "nisha",
"age": "24",
"Designation": "Teacher",
"_rev": "1-ed94f5772105ae15ae508a46f19f9941"
}
{
"_id": "003",
"name": "Asha",
"age": "25",
"Designation": "Mechanic",
"_rev": "1-513742e37a5cb67c2cb017f04fa329d8"
}
Read Also
- Now create a replication of this database in CouchDB:
//Requiring the package
var PouchDB = require('PouchDB');
var localDB = 'sample_database';
//Creating remote database object
var remoteDB = 'http://localhost:5984/sample_database';
//Replicating a local database to Remote
PouchDB.replicate(localDB, remoteDB);
console.log ("Database replicated successfully");
Save the file name as "Remote_Replication.js" within a folder name "PouchDB_Examples". Open the command prompt and execute the javascript file using node.
node Remote_Replication.js
Output
PouchDB Replication
Verification
- You can open CouchDB link and see that a database "sample_database" is created.
PouchDB Replication
PouchDB Replication
PouchDB Replication
PouchDB Replication
Replicate CouchDB to PouchDB
- Let's create a database named "remote_database" on CouchDB server with three documents doc1, doc2, and doc3, having contents as following:
doc1 = {_id: '001', name: 'princy', age: 20, Designation: 'Teacher'}
doc2 = {_id: '002', name: 'priya', age: 24, Designation: 'Lawyer'}
doc3 = {_id: '003', name: 'John', age: 36, Designation: 'Plumber'}
PouchDB Replication
- Let's replicate this database in local server PouchDB.
//Requiring the package
var PouchDB = require('PouchDB');
var localdb = 'remote_database';
var remotedb2 = 'http://localhost:5984/remote_database';
//Replicating a local database to Remote
PouchDB.replicate(remotdb, localdb);
console.log("Database replicated successfully to PouchDB");
Save the file name as "Local_Replication.js" within a folder name "PouchDB_Examples". Open the command prompt and execute the javascript file using node.
node Local_Replication.js
Read Also
Output:
PouchDB Replication
- You can verify if the database is replicated in your Pouch instance by using the following code.
//Requiring the package
var PouchDB = require('PouchDB');
//Creating the database object
var db = new PouchDB('remotedb');
//Retrieving all the documents in PouchDB
db.allDocs({include_docs: true, attachments: true}, function(err, docs) {
if (err) {
return console.log(err);
} else {
console.log(docs.rows);
}
});
- .Open the command prompt and execute the JavaScript file using node:
node Verify_Replication.js
Output
PouchDB Replication
[
{
id: '001',
key: '001',
value: { rev: '1-c1b32f27861dc6b2f16c22baf6547c9a' },
doc: {
name: 'princy',
age: '20',
Designation: 'Teacher',
_id: '001',
_rev: '1-c1b32f27861dc6b2f16c22baf6547c9a'
}
},
{
id: '002',
key: '002',
value: { rev: '1-57098ae011ecba8a95d5e42c1ec4ebb5' },
doc: {
name: 'priya',
age: '24',
Designation: 'Lawyer',
_id: '002',
_rev: '1-57098ae011ecba8a95d5e42c1ec4ebb5'
}
},
{
id: '003',
key: '003',
value: { rev: '1-1351db822f6565cee5ad7bbb08c6d27f' },
doc: {
name: 'John',
age: '36',
Designation: 'Plumber',
_id: '003',
_rev: '1-1351db822f6565cee5ad7bbb08c6d27f'
}
}
]