Khóa học miễn phí PouchDB – Read Document nhận dự án làm có lương

PouchDB – Read Document



You can read/retrieve the contents of a document in PouchDB using the db.get() method.

Syntax

Following is the syntax of using the db.get() method of PouchDB. This method accepts the document id and an optional callback function.

db.get(document, callback)

Example

Following is an example of reading the contents of a document in PouchDB using the get() method.

//Requiring the package
var PouchDB = require(''PouchDB'');

//Creating the database object
var db = new PouchDB(''my_database'');

//Reading the contents of a Document
db.get(''001'', function(err, doc) {
   if (err) {
      return console.log(err);
   } else {
      console.log(doc);
   }
});

Save the above code in a file with name Read_Document.js. Open the command prompt and execute the JavaScript file using node as shown below.

C:PouchDB_Examples >node Read_Document.js

This reads the contents of the given document that exists in the database named my_database which is stored locally. The following message gets displayed on the console.

{
   name: ''Raju'',
   age: 23,
   designation: ''Designer'',
   _id: ''001'',
   _rev: ''1-ba7f6914ac80098e6f63d2bfb0391637''
}

Reading a Document from a Remote Database

You can also read a document 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.

Reading a Document from a Remote Database

By clicking on the database named my_database you can see the following screenshot. Here, you can observe that this database contains a document with id 001.

Reading a Document

Following is an example of reading the contents of the document having id as “001” 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'');

//Reading the contents of a document
db.get(''001'', function(err, doc) {
   if (err) {
      return console.log(err);
   } else {
      console.log(doc);
   }
});

Save the above code in a file with the name Remote_Read_Document.js. Open the command prompt and execute the JavaScript file using node as shown below.

C:PouchDB_Examples >node Remote_Read_Document.js

This reads the contents of the given document that exists in the database named my_database which is stored in CouchDB. The following message is displayed on the console.

{ 
   _id: ''001'',
   _rev: ''3-552920d1ca372986fad7b996ce365f5d'',
   name: ''Raju'',
   age: 23,
   designation: ''Designer'' 
}

Khóa học lập trình tại Toidayhoc vừa học vừa làm dự án vừa nhận lương: Khóa học lập trình nhận lương tại trung tâm Toidayhoc