📚 Kivik - Awesome Go Library for Database Drivers
Kivik provides a common Go and GopherJS client library for CouchDB, PouchDB, and similar databases.
Detailed Description of Kivik
Kivik
Package kivik provides a common interface to CouchDB or CouchDB-like databases.
The kivik package must be used in conjunction with a database driver.
The kivik driver system is modeled after the standard library's sql and sql/driver packages, although the client API is completely different due to the different database models implemented by SQL and NoSQL databases such as CouchDB.
Versions
You are browsing the current stable branch of Kivik, v4. If you are upgrading from the previous stable version, v3, read the list of breaking changes.
Example configuration for common dependency managers follow.
Go Modules
Kivik 3.x and later supports Go modules, which is the recommended way to use it for Go version 1.11 or newer. Kivik 4.x only supports Go 1.17 and later. If your project is already using Go modules, simply fetch the desired version:
go get github.com/go-kivik/kivik/v4
Installation
Install Kivik as you normally would for any Go package:
go get -u github.com/go-kivik/kivik/v4
This will install the main Kivik package and the CouchDB database driver. Three officially supported drivers are shipped with this Go module:
- CouchDB: github.com/go-kivik/kivik/v4/couchdb
- PouchDB: github.com/go-kivik/kivik/v4/pouchdb (requires GopherJS)
- MockDB: github.com/go-kivik/kivik/v4/mockdb
In addition, there are partial/experimental drivers available:
- FilesystemDB: github.com/go-kivik/kivik/v4/x/fsdb
- MemoryDB: github.com/go-kivik/kivik/v4/x/memorydb
- SQLite: github.com/go-kivik/kivik/x/sqlite/v4
CLI
Consult the CLI README for full details on the kivik
CLI tool.
Example Usage
Please consult the the package documentation for all available API methods, and a complete usage documentation, and usage examples.
package main
import (
"context"
"fmt"
kivik "github.com/go-kivik/kivik/v4"
_ "github.com/go-kivik/kivik/v4/couchdb" // The CouchDB driver
)
func main() {
client, err := kivik.New("couch", "http://localhost:5984/")
if err != nil {
panic(err)
}
db := client.DB("animals")
doc := map[string]interface{}{
"_id": "cow",
"feet": 4,
"greeting": "moo",
}
rev, err := db.Put(context.TODO(), "cow", doc)
if err != nil {
panic(err)
}
fmt.Printf("Cow inserted with revision %s\n", rev)
}
Frequently Asked Questions
Nobody has ever asked me any of these questions, so they're probably better called "Never Asked Questions" or possibly "Imagined Questions."
Why another CouchDB client API?
I had a number of specific design goals when creating this package:
- Provide a generic database API for a variety of CouchDB-like databases. The previously existing drivers for CouchDB had patchy support for different versions of CouchDB, and different subsets of functionality.
- Work equally well with CouchDB 1.6, 2.x, 3.x, and any future versions, as well as PouchDB.
- Be as Go-idiomatic as possible.
- Be unambiguously open-source. Kivik is released under the Apache license, same as CouchDB and PouchDB.
- Separate out the basic implementation of a database driver (implementing the
kivik/driver
interfaces) vs the implementation of all the user-level types and convenience methods. It ought to be reasonably easy to create a new driver, for testing, mocking, implementing a new backend data storage system, or talking to other CouchDB-like databases.
What are Kivik's requirements?
Kivik's test suite is automatically run on Linux for every pull request, but should work on all supported Go architectures. If you find it not working for your OS/architecture, please submit a bug report.
Below are the compatibility targets for specific runtime and database versions. If you discover a bug affecting any of these supported environments, please let me know by submitting a bug report via GitHub.
- Go Kivik 4.x aims for full compatibility with all stable releases of Go from 1.13. For Go 1.7 or 1.8 you can use Kivik 1.x. For Go 1.9 through 1.12, you can use Kivik 3.x.
- CouchDB The Kivik 4.x CouchDB driver aims for compatibility with all stable releases of CouchDB from 2.x.
- GopherJS GopherJS always requires the latest stable version of Go, so building Kivik with GopherJS has this same requirement.
- PouchDB The Kivik 4.x PouchDB driver aims for compatibility with all stable releases of PouchDB from 8.0.0.
What is the development status?
Kivik 4.x is stable, and suitable for production use.
Why the name "Kivik"?
Kivik is a line of sofas (couches) from IKEA. And in the spirit of IKEA, and build-your-own furniture, Kivik aims to allow you to "build your own" CouchDB client, server, and proxy applications.
What license is Kivik released under?
Kivik is Copyright 2017-2023 by the Kivik contributors, and is released under the terms of the Apache 2.0 license. See LICENCE for the full text of the license.
Changes from 3.x to 4.x
This is a partial list of breaking changes between 3.x and 4.x
- Options are no longer a simple
map[string]interface{}
, but are rather functional parameters. In most cases, you can just usekivik.Param(key, value)
, orkivik.Params(map[string]interface{}{key: value})
as a replacement. Some shortcuts for common params now exist, and driver-specific options may work differently. Consult the GoDoc. - The
Authenticate
method has been removed. Authentication is now handled via option parameters. - The CouchDB, PouchDB, and MockDB drivers, and the experimental FilesystemDB and MemoryDB drivers, have been merged with this repo, rather than being hosted in separate repos. For v3 you would have imported
github.com/go-kivik/couchdb/v3
, for example. With v4, you instead usegithub.com/go-kivik/kivik/v4/couchdb
for CouchDB, orgithub.com/go-kivik/kivik/v4/x/fsdb
for the experimental FilesystemDB driver. - The return type for queries has been significantly changed.
- In 3.x, queries returned a
*Rows
struct. Now they return a*ResultSet
. - The
Offset()
,TotalRows()
,UpdateSeq()
,Warning()
andBookmark()
methods have been removed, and replaced with theResultMetadata
type which is accessed via theMetadata()
method. See issue #552. - Calling most methods on
ResultSet
will now work after closing the iterator. - The new
ResultSet
type supports multi-query mode, which is triggered by callingNextResultSet
beforeNext
. Key
,ID
,Rev
,Attachments
all now return row-specific errors, andScanKey
may successfully decode while also returning a row-specific error.
- In 3.x, queries returned a
- The
Changes
type has been changed to semantically match theResultSet
type. Specifically, theLastSeq()
andPending()
methods have been replaced by theMetadata()
method. - The
DBUpdates()
andChanges()
methods now defer errors to the iterator, for easier chaining and consistency with other iterators. DB.BulkDocs()
no longer returns an iterator, but rather an array of all results.Get
now returns a simpler*Result
type than before.GetMeta
has been replaced withGetRev
, and no longer claims to return the document size. The document size was never really the document size, rather it is theContent-Length
field of the HTTP response, which can vary depending on query parameters, making its use for determining document size dubious at best.- The
StatusCode() int
method on errors has been renamed toHTTPStatus() int
, to be more descriptive. The related package functionStatusCode(error) int
has also been renamed toHTTPStatus(error) int
to match. Client.Close()
andDB.Close()
now block until any relevant calls have returned.Client.Close()
andDB.Close()
no longer take acontext.Context
value. These operations cannot actually be canceled anyway, by the one driver that uses them (PouchDB); it only stops waiting. It makes more senes to make these functions blocking indefinitely, especially now that they wait for client requests to finish, and let the caller stop waiting if it wants to.
CouchDB specific changes
- The
SetTransport
authentication method has been removed, as a duplicate of couchdb.OptionHTTPClient. - Options passed to Kivik functions are now functional options, rather than a map of string to empty interface. As such, many of the options have changed. Consult the relevant GoDoc.
New features and additions
- Kivik now ships with the
kivik
command line tool (previously part of thegithub.com/go-kivik/xkivik
repository). - The new Replicate function allows replication between arbitrary databases, such as between CouchDB and a directory structure using the FilesystemDB.
What projects currently use Kivik?
If your project uses Kivik, and you'd like to be added to this list, create an issue or submit a pull request.
- Cayley is an open-source graph database. It uses Kivik for the CouchDB and PouchDB storage backends.