You can update an array of documents in PouchDB at once using the bulkDocs() method. To do so you need to create an array of documents where, each document contains _id, _rev and the values that are to be updated.
Suppose the database named my_database that is stored locally in PouchDB contains 3 documents namely doc1, doc2, doc3 with the following contents.
doc1 = {_id: ''001'', name: ''Ram'', age: 23, Designation: ''Programmer''}
doc2 = {_id: ''002'', name: ''Robert'', age: 24, Designation: ''Programmer''}
doc3 = {_id: ''003'', name: ''Rahim'', age: 25, Designation: ''Programmer''}
Suppose we have to increase the age values in all the 3 documents by 2 years. For this to happen, first you need to get the _rev values. Therefore, fetch the contents of these documents using the following code.
//Requiring the package
var PouchDB = require(''PouchDB'');
//Creating the database object
var db = new PouchDB(''my_database'');
//Retrieving all the documents in PouchDB
db.allDocs({include_docs: true},function(err, docs) {
if (err) {
return console.log(err);
} else {
console.log(docs.rows);
}
});
Save the above code as bulk_fetch.js. On executing, the above program gives you the _id and _rev values of the documents in the database as shown below.
[
{
id: ''001'',
key: ''001'',
value: { rev: ''1-1604b0c3ff69dc1e261265fd60808404'' }
},
{
id: ''002'',
key: ''002'',
value: { rev: ''1-b5e49db7e984841bf12a13e3ee548125'' }
},
{
id: ''003'',
key: ''003'',
value: { rev: ''1-a7b342786ecc707aa91f3b321a177b51'' }
}
]
Now, you can update the documents using their respective _id and _rev values as shown below.
//Requiring the package
var PouchDB = require(''PouchDB'');
//Creating the database object
var db = new PouchDB(''my_databas'');
//Preparing the document
docs = [{_id : ''001'', _rev: ''1-1604b0c3ff69dc1e261265fd60808404'', age : 25, },
{_id : ''002'', _rev: ''1-b5e49db7e984841bf12a13e3ee548125'', age : 26, },
{_id : ''003'', _rev: ''1-a7b342786ecc707aa91f3b321a177b51'', age : 27 }]
//Updating the documents in bulk
db.bulkDocs(docs, function(err, response) {
if (err) {
return console.log(err);
} else {
console.log("Documents Updated Successfully");
}
});
Save the above code in a file with the name Update_All_Document.js. Open the command prompt and execute the JavaScript file using node as shown below.
C:PouchDB_Examples >node Update_All_Document.js
This updates all the documents that exists in the database named my_database which is stored locally, displaying the following message.
Documents Updated Successfully
Now, if you execute the bulk_fetch.js program by adding {include_docs: true} as a parameter to allDocs() function, before the callback, then, you will can see the values of the documents updated, as shown below.
[
{
id: ''001'',
key: ''001'',
value: { rev: ''2-77f3a9974dd578d12f3f2a33aae64c8d'' },
doc: {
age: 25,
_id: ''001'',
_rev: ''2-77f3a9974dd578d12f3f2a33aae64c8d''
}
},
{
id: ''002'',
key: ''002'',
value: { rev: ''2-43966007568ce9567c96422195fcfa0d'' },
doc: {
age: 26,
_id: ''002'',
_rev: ''2-43966007568ce9567c96422195fcfa0d''
}
},
{
id: ''003'',
key: ''003'',
value: { rev: ''2-6c5349652527f4f39583ff14f23cd677'' },
doc: {
age: 27,
_id: ''003'',
_rev: ''2-6c5349652527f4f39583ff14f23cd677''
}
}
]
Updating Batch from a Remote Database
You can update all the documents from the database that is stored remotely on the server (CouchDB).
To do so, instead of a database name, you need to pass the path to the database in CouchDB, which contains the document that is to be read.
Example
Suppose there is a database named my_database in the CouchDB server. Then, if you verify the list of databases in CouchDB using the URL http://127.0.0.1:5984/_utils/index.html you will get the following screenshot.
And assume if we select the database named my_database, you can observe that it contains 3 documents as shown in the following screenshot.
Now, fetch the contents of these documents using the following code.
//Requiring the package
var PouchDB = require(''PouchDB'');
//Creating the database object
var db = new PouchDB(''http://localhost:5984/my_database'');
//Retrieving all the documents in PouchDB
db.allDocs({include_docs: true}, function(err, docs) {
if (err) {
return console.log(err);
} else {
console.log(docs.rows);
}
});
Save the above code as remote_bulk_fetch.js. On executing, the above program gives you the contents of all the documents in the database as shown below.
[
{
id: ''001'',
key: ''001'',
value: { rev: ''3-552920d1ca372986fad7b996ce365f5d'' },
doc: {
_id: ''001'',
_rev: ''3-552920d1ca372986fad7b996ce365f5d'',
name: ''Raju'',
age: 23,
designation: ''Designer''
}
},
{
id: ''002'',
key: ''002'',
value: { rev: ''1-9af15cb11054ebe03a7816bf6c5e4128'' },
doc: {
_id: ''002'',
_rev: ''1-9af15cb11054ebe03a7816bf6c5e4128'',
name: ''Robert'',
age: 24,
Designation: ''Programmer''
}
},
{
id: ''003'',
key: ''003'',
value: { rev: ''1-3033b5a78e915c52fd37325d42eb3935'' },
doc: {
_id: ''003'',
_rev: ''1-3033b5a78e915c52fd37325d42eb3935'',
name: ''Rahim'',
age: 25,
Designation: ''Programmer''
}
}
]
Following is an example of updating all the documents that exists in a database named my_database which is stored in the CouchDB server.
//Requiring the package
var PouchDB = require(''PouchDB'');
//Creating the database object
var db = new PouchDB(''http://localhost:5984/my_database'');
//Preparing the document
docs = [{_id : ''001'', _rev: ''3-552920d1ca372986fad7b996ce365f5d'', age : 24, },
{_id : ''002'', _rev: ''1-9af15cb11054ebe03a7816bf6c5e4128'', age : 26, },
{_id : ''003'', _rev: ''1-3033b5a78e915c52fd37325d42eb3935'', age : 27}]
//Inserting Document
db.bulkDocs(docs, function(err, response) {
if (err) {
return console.log(err);
} else {
console.log(+"Documents Updated Successfully");
}
});
Save the above code in a file with the name Remote_Update_Document.js. Open the command prompt and execute the JavaScript file using node as shown below.
C:PouchDB_Examples >node Remote_Update_Document.js
This updates the contents of all given document that exists in the database named my_database which is stored in CouchDB, and displays the following message.
Documents Updated Successfully
Now, if you execute the remote_bulk_fetch.js program you will can see the values of the documents updated, as shown below.
[
{
id: ''001'',
key: ''001'',
value: { rev: ''4-6bc8d9c7a60fed2ed1667ec0740c1f39'' },
doc: {
_id: ''001'',
_rev: ''4-6bc8d9c7a60fed2ed1667ec0740c1f39'',
age: 25
}
},
{
id: ''002'',
key: ''002'',
value: { rev: ''2-1aa24ce77d96bb9d2a0675cdf1e113e0'' },
doc: {
_id: ''002'',
_rev: ''2-1aa24ce77d96bb9d2a0675cdf1e113e0'',
age: 26
}
},
{
id: ''003'',
key: ''003'',
value: { rev: ''2-fa113149ba618eda77f73072974a2bc1'' },
doc: {
_id: ''003'',
_rev: ''2-fa113149ba618eda77f73072974a2bc1'',
age: 27
}
}
]
