1.5.4. /{db}/_design/{ddoc}/_view/{view}
¶
- GET /{db}/_design/{ddoc}/_view/{view}¶
Executes the specified view function from the specified design document.
- Parameters:
db – Database name
ddoc – Design document name
view – View function name
- Request Headers:
Accept –
application/json
text/plain
- Query Parameters:
conflicts (boolean) – Include conflicts information in response. Ignored if
include_docs
isn’ttrue
. Default isfalse
.descending (boolean) – Return the documents in descending order by key. Default is
false
.endkey (json) – Stop returning records when the specified key is reached.
end_key (json) – Alias for
endkey
paramendkey_docid (string) – Stop returning records when the specified document ID is reached. Ignored if
endkey
is not set.end_key_doc_id (string) – Alias for
endkey_docid
.group (boolean) – Group the results using the reduce function to a group or single row. Implies
reduce
istrue
and the maximumgroup_level
. Default isfalse
.group_level (number) – Specify the group level to be used. Implies
group
istrue
.include_docs (boolean) – Include the associated document with each row. Default is
false
.attachments (boolean) – Include the Base64-encoded content of attachments in the documents that are included if
include_docs
istrue
. Ignored ifinclude_docs
isn’ttrue
. Default isfalse
.att_encoding_info (boolean) – Include encoding information in attachment stubs if
include_docs
istrue
and the particular attachment is compressed. Ignored ifinclude_docs
isn’ttrue
. Default isfalse
.inclusive_end (boolean) – Specifies whether the specified end key should be included in the result. Default is
true
.key (json) – Return only documents that match the specified key.
keys (json-array) – Return only documents where the key matches one of the keys specified in the array.
limit (number) – Limit the number of the returned documents to the specified number.
reduce (boolean) – Use the reduction function. Default is
true
when a reduce function is defined.skip (number) – Skip this number of records before starting to return the results. Default is
0
.sorted (boolean) – Sort returned rows (see Sorting Returned Rows). Setting this to
false
offers a performance boost. Thetotal_rows
andoffset
fields are not available when this is set tofalse
. Default istrue
.stable (boolean) – Whether or not the view results should be returned from a stable set of shards. Default is
false
.stale (string) – Allow the results from a stale view to be used. Supported values:
ok
andupdate_after
.ok
is equivalent tostable=true&update=false
.update_after
is equivalent tostable=true&update=lazy
. The default behavior is equivalent tostable=false&update=true
. Note that this parameter is deprecated. Usestable
andupdate
instead. See Views Generation for more details.startkey (json) – Return records starting with the specified key.
start_key (json) – Alias for
startkey
.startkey_docid (string) – Return records starting with the specified document ID. Ignored if
startkey
is not set.start_key_doc_id (string) – Alias for
startkey_docid
paramupdate (string) – Whether or not the view in question should be updated prior to responding to the user. Supported values:
true
,false
,lazy
. Default istrue
.update_seq (boolean) – Whether to include in the response an
update_seq
value indicating the sequence id of the database the view reflects. Default isfalse
.
- Response Headers:
application/json
text/plain; charset=utf-8
ETag – Response signature
Transfer-Encoding –
chunked
- Response JSON Object:
offset (number) – Offset where the document list started.
rows (array) – Array of view row objects. By default the information returned contains only the document ID and revision.
total_rows (number) – Number of documents in the database/view.
update_seq (object) – Current update sequence for the database.
- Status Codes:
200 OK – Request completed successfully
400 Bad Request – Invalid request
401 Unauthorized – Read permission required
404 Not Found – Specified database, design document or view is missed
Request:
GET /recipes/_design/ingredients/_view/by_name HTTP/1.1 Accept: application/json Host: localhost:5984
Response:
HTTP/1.1 200 OK Cache-Control: must-revalidate Content-Type: application/json Date: Wed, 21 Aug 2013 09:12:06 GMT ETag: "2FOLSBSW4O6WB798XU4AQYA9B" Server: CouchDB (Erlang/OTP) Transfer-Encoding: chunked { "offset": 0, "rows": [ { "id": "SpaghettiWithMeatballs", "key": "meatballs", "value": 1 }, { "id": "SpaghettiWithMeatballs", "key": "spaghetti", "value": 1 }, { "id": "SpaghettiWithMeatballs", "key": "tomato sauce", "value": 1 } ], "total_rows": 3 }
Changed in version 1.6.0: added attachments
and att_encoding_info
parameters
Changed in version 2.0.0: added sorted
parameter
Changed in version 2.1.0: added stable
and update
parameters
Changed in version 3.3.1: treat single-element keys
as key
Warning
Using the attachments
parameter to include attachments in view results
is not recommended for large attachment sizes. Also note that the
Base64-encoding that is used leads to a 33% overhead (i.e. one third) in
transfer size for attachments.
- POST /{db}/_design/{ddoc}/_view/{view}¶
Executes the specified view function from the specified design document. POST view functionality supports identical parameters and behavior as specified in the
GET /{db}/_design/{ddoc}/_view/{view}
API but allows for the query string parameters to be supplied as keys in a JSON object in the body of the POST request.Request:
POST /recipes/_design/ingredients/_view/by_name HTTP/1.1 Accept: application/json Content-Length: 37 Host: localhost:5984 { "keys": [ "meatballs", "spaghetti" ] }
Response:
HTTP/1.1 200 OK Cache-Control: must-revalidate Content-Type: application/json Date: Wed, 21 Aug 2013 09:14:13 GMT ETag: "6R5NM8E872JIJF796VF7WI3FZ" Server: CouchDB (Erlang/OTP) Transfer-Encoding: chunked { "offset": 0, "rows": [ { "id": "SpaghettiWithMeatballs", "key": "meatballs", "value": 1 }, { "id": "SpaghettiWithMeatballs", "key": "spaghetti", "value": 1 } ], "total_rows": 3 }
1.5.4.1. View Options¶
There are two view indexing options that can be defined in a design document
as boolean properties of an options
object. Unlike the others querying
options, these aren’t URL parameters because they take effect when the view
index is generated, not when it’s accessed:
local_seq (boolean): Makes documents’ local sequence numbers available to map functions (as a
_local_seq
document property)include_design (boolean): Allows map functions to be called on design documents as well as regular documents
1.5.4.2. Querying Views and Indexes¶
The definition of a view within a design document also creates an index based on the key information defined within each view. The production and use of the index significantly increases the speed of access and searching or selecting documents from the view.
However, the index is not updated when new documents are added or modified in the database. Instead, the index is generated or updated, either when the view is first accessed, or when the view is accessed after a document has been updated. In each case, the index is updated before the view query is executed against the database.
View indexes are updated incrementally in the following situations:
A new document has been added to the database.
A document has been deleted from the database.
A document in the database has been updated.
View indexes are rebuilt entirely when the view definition changes. To achieve
this, a fingerprint
of the view definition is created when the design
document is updated. If the fingerprint changes, then the view indexes are
entirely rebuilt. This ensures that changes to the view definitions are
reflected in the view indexes.
Note
View index rebuilds occur when one view from the same the view group (i.e. all the views defined within a single a design document) has been determined as needing a rebuild. For example, if you have a design document with different views, and you update the database, all three view indexes within the design document will be updated.
Because the view is updated when it has been queried, it can result in a delay in returned information when the view is accessed, especially if there are a large number of documents in the database and the view index does not exist. There are a number of ways to mitigate, but not completely eliminate, these issues. These include:
Create the view definition (and associated design documents) on your database before allowing insertion or updates to the documents. If this is allowed while the view is being accessed, the index can be updated incrementally.
Manually force a view request from the database. You can do this either before users are allowed to use the view, or you can access the view manually after documents are added or updated.
Use the changes feed to monitor for changes to the database and then access the view to force the corresponding view index to be updated.
None of these can completely eliminate the need for the indexes to be rebuilt or updated when the view is accessed, but they may lessen the effects on end-users of the index update affecting the user experience.
Another alternative is to allow users to access a ‘stale’ version of the view index, rather than forcing the index to be updated and displaying the updated results. Using a stale view may not return the latest information, but will return the results of the view query using an existing version of the index.
For example, to access the existing stale view by_recipe
in the
recipes
design document:
http://localhost:5984/recipes/_design/recipes/_view/by_recipe?stale=ok
Accessing a stale view:
Does not trigger a rebuild of the view indexes, even if there have been changes since the last access.
Returns the current version of the view index, if a current version exists.
Returns an empty result set if the given view index does not exist.
As an alternative, you use the update_after
value to the stale
parameter. This causes the view to be returned as a stale view, but for the
update process to be triggered after the view information has been returned to
the client.
In addition to using stale views, you can also make use of the update_seq
query argument. Using this query argument generates the view information
including the update sequence of the database from which the view was
generated. The returned value can be compared this to the current update
sequence exposed in the database information (returned by GET /{db}
).
1.5.4.3. Sorting Returned Rows¶
Each element within the returned array is sorted using native UTF-8 sorting according to the contents of the key portion of the emitted content. The basic order of output is as follows:
null
false
true
Numbers
Text (case sensitive, lowercase first)
Arrays (according to the values of each element, in order)
Objects (according to the values of keys, in key order)
Request:
GET /db/_design/test/_view/sorting HTTP/1.1
Accept: application/json
Host: localhost:5984
Response:
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Wed, 21 Aug 2013 10:09:25 GMT
ETag: "8LA1LZPQ37B6R9U8BK9BGQH27"
Server: CouchDB (Erlang/OTP)
Transfer-Encoding: chunked
{
"offset": 0,
"rows": [
{
"id": "dummy-doc",
"key": null,
"value": null
},
{
"id": "dummy-doc",
"key": false,
"value": null
},
{
"id": "dummy-doc",
"key": true,
"value": null
},
{
"id": "dummy-doc",
"key": 0,
"value": null
},
{
"id": "dummy-doc",
"key": 1,
"value": null
},
{
"id": "dummy-doc",
"key": 10,
"value": null
},
{
"id": "dummy-doc",
"key": 42,
"value": null
},
{
"id": "dummy-doc",
"key": "10",
"value": null
},
{
"id": "dummy-doc",
"key": "hello",
"value": null
},
{
"id": "dummy-doc",
"key": "Hello",
"value": null
},
{
"id": "dummy-doc",
"key": "\u043f\u0440\u0438\u0432\u0435\u0442",
"value": null
},
{
"id": "dummy-doc",
"key": [],
"value": null
},
{
"id": "dummy-doc",
"key": [
1,
2,
3
],
"value": null
},
{
"id": "dummy-doc",
"key": [
2,
3
],
"value": null
},
{
"id": "dummy-doc",
"key": [
3
],
"value": null
},
{
"id": "dummy-doc",
"key": {},
"value": null
},
{
"id": "dummy-doc",
"key": {
"foo": "bar"
},
"value": null
}
],
"total_rows": 17
}
You can reverse the order of the returned view information
by using the descending
query value set to true:
Request:
GET /db/_design/test/_view/sorting?descending=true HTTP/1.1
Accept: application/json
Host: localhost:5984
Response:
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Wed, 21 Aug 2013 10:09:25 GMT
ETag: "Z4N468R15JBT98OM0AMNSR8U"
Server: CouchDB (Erlang/OTP)
Transfer-Encoding: chunked
{
"offset": 0,
"rows": [
{
"id": "dummy-doc",
"key": {
"foo": "bar"
},
"value": null
},
{
"id": "dummy-doc",
"key": {},
"value": null
},
{
"id": "dummy-doc",
"key": [
3
],
"value": null
},
{
"id": "dummy-doc",
"key": [
2,
3
],
"value": null
},
{
"id": "dummy-doc",
"key": [
1,
2,
3
],
"value": null
},
{
"id": "dummy-doc",
"key": [],
"value": null
},
{
"id": "dummy-doc",
"key": "\u043f\u0440\u0438\u0432\u0435\u0442",
"value": null
},
{
"id": "dummy-doc",
"key": "Hello",
"value": null
},
{
"id": "dummy-doc",
"key": "hello",
"value": null
},
{
"id": "dummy-doc",
"key": "10",
"value": null
},
{
"id": "dummy-doc",
"key": 42,
"value": null
},
{
"id": "dummy-doc",
"key": 10,
"value": null
},
{
"id": "dummy-doc",
"key": 1,
"value": null
},
{
"id": "dummy-doc",
"key": 0,
"value": null
},
{
"id": "dummy-doc",
"key": true,
"value": null
},
{
"id": "dummy-doc",
"key": false,
"value": null
},
{
"id": "dummy-doc",
"key": null,
"value": null
}
],
"total_rows": 17
}
1.5.4.3.1. Sorting order and startkey/endkey¶
The sorting direction is applied before the filtering applied using the
startkey
and endkey
query arguments. For example the following query
will operate correctly when listing all the matching entries between
carrots
and egg
:
GET http://couchdb:5984/recipes/_design/recipes/_view/by_ingredient?startkey="carrots"&endkey="egg" HTTP/1.1
Accept: application/json
If the order of output is reversed with the descending
query argument,
the view request will get a 400 Bad Request response:
GET /recipes/_design/recipes/_view/by_ingredient?descending=true&startkey="carrots"&endkey="egg" HTTP/1.1
Accept: application/json
Host: localhost:5984
{
"error": "query_parse_error",
"reason": "No rows can match your key range, reverse your start_key and end_key or set descending=false",
"ref": 3986383855
}
The result will be an error because the entries in the view are reversed before
the key filter is applied, so the endkey
of “egg” will be seen before the
startkey
of “carrots”.
Instead, you should reverse the values supplied to the startkey
and
endkey
parameters to match the descending sorting applied to the keys.
Changing the previous example to:
GET /recipes/_design/recipes/_view/by_ingredient?descending=true&startkey="egg"&endkey="carrots" HTTP/1.1
Accept: application/json
Host: localhost:5984
1.5.4.3.2. Using key, keys, start_key and end_key¶
key
: Behaves like setting start_key=$key&end_key=$key
.
keys
: there are some differences between single-element keys
and
multi-element keys
. For single-element keys
, treat it as a key
.
$ curl -X POST http://adm:pass@127.0.0.1:5984/db/_bulk_docs \
-H 'Content-Type: application/json' \
-d '{"docs":[{"_id":"a","key":"a","value":1},{"_id":"b","key":"b","value":2},{"_id":"c","key":"c","value":3}]}'
$ curl -X POST http://adm:pass@127.0.0.1:5984/db \
-H 'Content-Type: application/json' \
-d '{"_id":"_design/ddoc","views":{"reduce":{"map":"function(doc) { emit(doc.key, doc.value) }","reduce":"_sum"}}}'
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?key="a"'
{"rows":[{"key":null,"value":1}]}
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?keys="[\"a\"]"'
{"rows":[{"key":null,"value":1}]}
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?keys=\["a","b"\]'
{"error":"query_parse_error","reason":"Multi-key fetches for reduce views must use `group=true`"}
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?keys=\["a","c"\]&group=true'
{"rows":[{"key":"a","value":1},{"key":"c","value":3}]}
keys
is incompatible with key
, start_key
and end_key
,
but it’s possible to use key
with start_key
and end_key
.
Different orders of query parameters may result in different responses.
Precedence is the order in which query parameters are specified. Usually,
the last argument wins.
# start_key=a and end_key=b
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?key="a"&endkey="b"'
{"rows":[{"key":null,"value":3}]}
# start_key=a and end_key=a
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&key="a"'
{"rows":[{"key":null,"value":1}]}
# start_key=a and end_key=a
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&keys=\["a"\]'
{"rows":[{"key":null,"value":1}]}
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&keys=\["a","b"\]'
{"error":"query_parse_error","reason":"Multi-key fetches for reduce views must use `group=true`"}
$ curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&keys=\["a","b"\]&group=true'
{"error":"query_parse_error","reason":"`keys` is incompatible with `key`, `start_key` and `end_key`"}
1.5.4.3.3. Raw collation¶
By default CouchDB uses an ICU driver for sorting view results. It’s possible use binary collation instead for faster view builds where Unicode collation is not important.
To use raw collation add "options":{"collation":"raw"}
within the view object of the
design document. After that, views will be regenerated and new order applied for the
appropriate view.
See also
1.5.4.4. Using Limits and Skipping Rows¶
By default, views return all results. That’s ok when the number of results is small, but this may lead to problems when there are billions results, since the client may have to read them all and consume all available memory.
But it’s possible to reduce output result rows by specifying limit
query
parameter. For example, retrieving the list of recipes using the by_title
view and limited to 5 returns only 5 records, while there are total 2667
records in view:
Request:
GET /recipes/_design/recipes/_view/by_title?limit=5 HTTP/1.1
Accept: application/json
Host: localhost:5984
Response:
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Wed, 21 Aug 2013 09:14:13 GMT
ETag: "9Q6Q2GZKPH8D5F8L7PB6DBSS9"
Server: CouchDB (Erlang/OTP)
Transfer-Encoding: chunked
{
"offset" : 0,
"rows" : [
{
"id" : "3-tiersalmonspinachandavocadoterrine",
"key" : "3-tier salmon, spinach and avocado terrine",
"value" : [
null,
"3-tier salmon, spinach and avocado terrine"
]
},
{
"id" : "Aberffrawcake",
"key" : "Aberffraw cake",
"value" : [
null,
"Aberffraw cake"
]
},
{
"id" : "Adukiandorangecasserole-microwave",
"key" : "Aduki and orange casserole - microwave",
"value" : [
null,
"Aduki and orange casserole - microwave"
]
},
{
"id" : "Aioli-garlicmayonnaise",
"key" : "Aioli - garlic mayonnaise",
"value" : [
null,
"Aioli - garlic mayonnaise"
]
},
{
"id" : "Alabamapeanutchicken",
"key" : "Alabama peanut chicken",
"value" : [
null,
"Alabama peanut chicken"
]
}
],
"total_rows" : 2667
}
To omit some records you may use skip
query parameter:
Request:
GET /recipes/_design/recipes/_view/by_title?limit=3&skip=2 HTTP/1.1
Accept: application/json
Host: localhost:5984
Response:
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Wed, 21 Aug 2013 09:14:13 GMT
ETag: "H3G7YZSNIVRRHO5FXPE16NJHN"
Server: CouchDB (Erlang/OTP)
Transfer-Encoding: chunked
{
"offset" : 2,
"rows" : [
{
"id" : "Adukiandorangecasserole-microwave",
"key" : "Aduki and orange casserole - microwave",
"value" : [
null,
"Aduki and orange casserole - microwave"
]
},
{
"id" : "Aioli-garlicmayonnaise",
"key" : "Aioli - garlic mayonnaise",
"value" : [
null,
"Aioli - garlic mayonnaise"
]
},
{
"id" : "Alabamapeanutchicken",
"key" : "Alabama peanut chicken",
"value" : [
null,
"Alabama peanut chicken"
]
}
],
"total_rows" : 2667
}
Warning
Using limit
and skip
parameters is not recommended for results
pagination. Read pagination recipe why it’s so
and how to make it better.
1.5.4.5. Sending multiple queries to a view¶
Added in version 2.2.
- POST /{db}/_design/{ddoc}/_view/{view}/queries¶
Executes multiple specified view queries against the view function from the specified design document.
- Parameters:
db – Database name
ddoc – Design document name
view – View function name
- Request Headers:
application/json
Accept –
application/json
- Request JSON Object:
queries – An array of query objects with fields for the parameters of each individual view query to be executed. The field names and their meaning are the same as the query parameters of a regular view request.
- Response Headers:
application/json
ETag – Response signature
Transfer-Encoding –
chunked
- Response JSON Object:
results (array) – An array of result objects - one for each query. Each result object contains the same fields as the response to a regular view request.
- Status Codes:
200 OK – Request completed successfully
400 Bad Request – Invalid request
401 Unauthorized – Read permission required
404 Not Found – Specified database, design document or view is missing
500 Internal Server Error – View function execution error
Request:
POST /recipes/_design/recipes/_view/by_title/queries HTTP/1.1
Content-Type: application/json
Accept: application/json
Host: localhost:5984
{
"queries": [
{
"keys": [
"meatballs",
"spaghetti"
]
},
{
"limit": 3,
"skip": 2
}
]
}
Response:
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Wed, 20 Dec 2016 11:17:07 GMT
ETag: "1H8RGBCK3ABY6ACDM7ZSC30QK"
Server: CouchDB (Erlang/OTP)
Transfer-Encoding: chunked
{
"results" : [
{
"offset": 0,
"rows": [
{
"id": "SpaghettiWithMeatballs",
"key": "meatballs",
"value": 1
},
{
"id": "SpaghettiWithMeatballs",
"key": "spaghetti",
"value": 1
},
{
"id": "SpaghettiWithMeatballs",
"key": "tomato sauce",
"value": 1
}
],
"total_rows": 3
},
{
"offset" : 2,
"rows" : [
{
"id" : "Adukiandorangecasserole-microwave",
"key" : "Aduki and orange casserole - microwave",
"value" : [
null,
"Aduki and orange casserole - microwave"
]
},
{
"id" : "Aioli-garlicmayonnaise",
"key" : "Aioli - garlic mayonnaise",
"value" : [
null,
"Aioli - garlic mayonnaise"
]
},
{
"id" : "Alabamapeanutchicken",
"key" : "Alabama peanut chicken",
"value" : [
null,
"Alabama peanut chicken"
]
}
],
"total_rows" : 2667
}
]
}