PouchDB Delete Attachment
PouchDB Delete Attachment
- removeAttachment() - This method is used to delete an attachment from PouchDB. To delete an attachment, We have to pass the document_id, attachment_id and _rev value.
- This method takes an callback function as a optional parameter.
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/syntax-delete.png)
PouchDB Delete Attachment
Syntax:
db.removeAttachment ( doc_Id, attachment_Id, rev, [callback] );
Example
We have a document in PouchDB with id 002, which contains id, name, age, designation of an employee with attachment.
{
"_id": "001",
"name": "admin",
"age": "28",
"_attachments": {
"att_1.txt": {
"digest": "md5-k7iFrf4NoInN9jSQT9WfcQ==",
"content_type": "text/plain",
"length": 1,
"revpos": 3,
"stub": true
}
},
"_rev": "4-97990b4971035c69450d0f1cf4b6a6f5"
}
- Let's remove the attachment by using removeAttachment() method.
//Requiring the package
var PouchDB = require('PouchDB');
//Creating the database object
var db = new PouchDB('Last_Database');
db.removeAttachment('002', 'attachment_1.txt', '4-97990b4971035c69450d0f1cf4b6a6f5',
function(err, res) {
if (err) {
return console.log(err);
} else {
console.log(res+"document Deleted successfully")
}
});
Save the file name as "Del_Attachment.js " within a folder name "PouchDB_Examples". Open the command prompt and execute the javascript file using node.
node Del_Attachment.js
Output
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/delete-batch-1.png)
PouchDB Delete Attachment
- Attachment is deleted successfully.
Verification
Using read command to verify that the attachment is deleted from the document.
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/delete-batch-2.png)
PouchDB Delete Attachment
Delete Attachment from a Remote Database
Additionally we can delete an attachment in a database that is stored remotely on a server (CouchDB). For this purpose, You just have to pass the path to the database where you want to delete the attachment in CouchDB.
Example
- We have a database name "employees" stored on the CouchDB server
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/pouchdb-delete-attachment-4.png)
PouchDB Delete Attachment
- The database "employees" has a document having id "001".
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/delete-attachment-1.png)
PouchDB Delete Attachment
- Let's delete the attachment.
//Requiring the package
var PouchDB = require('PouchDB');
//Creating the database object
var db = new PouchDB('http://localhost:5984/employees');
db.removeAttachment('001', 'att_1.txt', '4-97990b4971035c69450d0f1cf4b6a6f5',
function(err, res) {
if (err) {
return console.log(err);
} else {
console.log(res+"Attachment Deleted successfully")
}
});
Save the file name as "Delete_Remote_Attachment.js" within a folder name "PouchDB_Examples". Open the command prompt and execute the javascript file using node.
node Delete_Remote_Attachment.js
Output:
![PouchDB Delete Attachment](https://cdn.wikitechy.com/tutorial/pouchdb/pouchdb-delete-attachment-6.png)
PouchDB Delete Attachment