{% include anchor.html edit="true" title="Get an attachment" hash="get_attachment" %} {% highlight js %} db.getAttachment(docId, attachmentId, [options], [callback]) {% endhighlight %} Get attachment data. ### Options * `options.rev`: as with [get()](#fetch_document), you can pass a `rev` in and get back an attachment for the document at that particular revision. #### Example Usage: Get an attachment with filename `'att.txt'` from document with ID `'doc'`: {% include code/start.html id="get_att1" type="callback" %} {% highlight js %} db.getAttachment('doc', 'att.txt', function(err, blobOrBuffer) { if (err) { return console.log(err); } // handle result }); {% endhighlight %} {% include code/end.html %} {% include code/start.html id="get_att1" type="async" %} {% highlight js %} try { var blobOrBuffer = await db.getAttachment('doc', 'att.txt'); } catch (err) { console.log(err); } {% endhighlight %} {% include code/end.html %} {% include code/start.html id="get_att1" type="promise" %} {% highlight js %} db.getAttachment('doc', 'att.txt').then(function (blobOrBuffer) { // handle result }).catch(function (err) { console.log(err); }); {% endhighlight %} {% include code/end.html %} Get an attachment with filename `'att.txt'` from document with ID `'doc'`, at the revision `'1-abcd'`: {% include code/start.html id="get_att2" type="callback" %} {% highlight js %} db.getAttachment('doc', 'att.txt', {rev: '1-abcd'}, function(err, blobOrBuffer) { if (err) { return console.log(err); } // handle result }); {% endhighlight %} {% include code/end.html %} {% include code/start.html id="get_att2" type="async" %} {% highlight js %} try { var blobOrBuffer = await db.getAttachment('doc', 'att.txt', {rev: '1-abcd'}); } catch (err) { console.log(err); } {% endhighlight %} {% include code/end.html %} {% include code/start.html id="get_att2" type="promise" %} {% highlight js %} db.getAttachment('doc', 'att.txt', {rev: '1-abcd'}).then(function (blobOrBuffer) { // handle result }).catch(function (err) { console.log(err); }); {% endhighlight %} {% include code/end.html %} #### Response type: The response will be a `Blob` object in the browser, and a `Buffer` object in Node.js. See [blob-util](https://github.com/nolanlawson/blob-util) for utilities to transform `Blob`s to other formats, such as base64-encoded strings, data URLs, array buffers, etc. #### Inline base64 attachments You can specify `{attachments: true}` to most "read" operations, such as `get()`, `allDocs()`, `changes()`, and `query()`. The attachment data will then be included inlined in the resulting doc(s). However, it will always be supplied as base64. For example: {% highlight js %} { "_attachments": { "att.txt": { "content_type": "text/plain", "digest": "d5ccfd24a8748bed4e2c9a279a2b6089", "data": "SXMgdGhlcmUgbGlmZSBvbiBNYXJzPw==" } }, "_id": "mydoc", "_rev": "1-e147d9ec9c85139dfe7e93bc17148d1a" } {% endhighlight %} For such APIs, when you don't specify `{attachments: true}`, you will instead get metadata about the attachments. For example: {% highlight js %} { "_attachments": { "att.txt": { "content_type": "text/plain", "digest": "d5ccfd24a8748bed4e2c9a279a2b6089", "stub": true } }, "_id": "mydoc", "_rev": "1-e147d9ec9c85139dfe7e93bc17148d1a" } {% endhighlight %} This "summary" operation may be faster in some cases, because the attachment itself does not need to be read from disk.