base on A MySQL-compatible relational database with a storage agnostic query engine. Implemented in pure Go. <img height="240" src="./mascot.png"/>
# A MySQL compatible database engine written in pure Go
**go-mysql-server** is a data-source agnostic SQL engine and server
which runs queries on data sources you provide, using the MySQL
dialect and wire protocol. A simple in-memory database implementation
is included, and you can query any data source you want by
implementing your own backend.
[Dolt](https://www.doltdb.com), a SQL database with Git-style
versioning, is the main production database implementation of this
package. [Check
out](https://docs.dolthub.com/introduction/what-is-dolt) that project
for a reference implementation. Or, hop into the Dolt Discord server
[here](https://discord.com/invite/RFwfYpu) if you want to talk to the
[core developers](https://www.dolthub.com/team) behind
**go-mysql-server** and Dolt.
## Compatibility
With the exception of specific limitations (see below),
**go-mysql-server** is a drop-in replacement for MySQL. Any client
library, tool, query, SQL syntax, SQL function, etc. that works with
MySQL should also work with **go-mysql-server**. If you find a gap in
functionality, please file an issue.
For full MySQL compatibility documentation, see the [Dolt
docs](https://docs.dolthub.com/sql-reference/sql-support) on this
topic.
## Scope of this project
- SQL server and engine to query your data sources.
- In-memory database backend implementation suitable for use in tests.
- Interfaces you can use to implement new backends to query your own
data sources.
- With a few caveats and using a full database implementation, a
drop-in MySQL database replacement.
**go-mysql-server** has two primary uses case:
1. Stand-in for MySQL in a golang test environment, using the built-in
`memory` database implementation.
2. Providing access to arbitrary data sources with SQL queries by
implementing a handful of interfaces. The most complete real-world
implementation is [Dolt](https://github.com/dolthub/dolt).
## Installation
Add **go-mysql-server** as a dependency to your project. In the
directory with the `go.mod` file, run:
```
go get github.com/dolthub/go-mysql-server@latest
```
## Using the in-memory test server
The in-memory test server can replace a real MySQL server in
tests. Start the server using the code in the [_example
directory](_example/main.go), also reproduced below.
```go
package main
import (
"context"
"fmt"
"time"
"github.com/dolthub/vitess/go/vt/proto/query"
sqle "github.com/dolthub/go-mysql-server"
"github.com/dolthub/go-mysql-server/memory"
"github.com/dolthub/go-mysql-server/server"
"github.com/dolthub/go-mysql-server/sql"
"github.com/dolthub/go-mysql-server/sql/types"
)
// This is an example of how to implement a MySQL server.
// After running the example, you may connect to it using the following:
//
// > mysql --host=localhost --port=3306 --user=root mydb --execute="SELECT * FROM mytable;"
// +----------+-------------------+-------------------------------+----------------------------+
// | name | email | phone_numbers | created_at |
// +----------+-------------------+-------------------------------+----------------------------+
// | Jane Deo |
[email protected] | ["556-565-566","777-777-777"] | 2022-11-01 12:00:00.000001 |
// | Jane Doe |
[email protected] | [] | 2022-11-01 12:00:00.000001 |
// | John Doe |
[email protected] | ["555-555-555"] | 2022-11-01 12:00:00.000001 |
// | John Doe |
[email protected] | [] | 2022-11-01 12:00:00.000001 |
// +----------+-------------------+-------------------------------+----------------------------+
//
// The included MySQL client is used in this example, however any MySQL-compatible client will work.
var (
dbName = "mydb"
tableName = "mytable"
address = "localhost"
port = 3306
)
func main() {
pro := createTestDatabase()
engine := sqle.NewDefault(pro)
session := memory.NewSession(sql.NewBaseSession(), pro)
ctx := sql.NewContext(context.Background(), sql.WithSession(session))
ctx.SetCurrentDatabase(dbName)
// This variable may be found in the "users_example.go" file. Please refer to that file for a walkthrough on how to
// set up the "mysql" database to allow user creation and user checking when establishing connections. This is set
// to false for this example, but feel free to play around with it and see how it works.
if enableUsers {
if err := enableUserAccounts(ctx, engine); err != nil {
panic(err)
}
}
config := server.Config{
Protocol: "tcp",
Address: fmt.Sprintf("%s:%d", address, port),
}
s, err := server.NewServer(config, engine, sql.NewContext, memory.NewSessionBuilder(pro), nil)
if err != nil {
panic(err)
}
if err = s.Start(); err != nil {
panic(err)
}
}
func createTestDatabase() *memory.DbProvider {
db := memory.NewDatabase(dbName)
db.BaseDatabase.EnablePrimaryKeyIndexes()
pro := memory.NewDBProvider(db)
session := memory.NewSession(sql.NewBaseSession(), pro)
ctx := sql.NewContext(context.Background(), sql.WithSession(session))
table := memory.NewTable(db, tableName, sql.NewPrimaryKeySchema(sql.Schema{
{Name: "name", Type: types.Text, Nullable: false, Source: tableName, PrimaryKey: true},
{Name: "email", Type: types.Text, Nullable: false, Source: tableName, PrimaryKey: true},
{Name: "phone_numbers", Type: types.JSON, Nullable: false, Source: tableName},
{Name: "created_at", Type: types.MustCreateDatetimeType(query.Type_DATETIME, 6), Nullable: false, Source: tableName},
}), db.GetForeignKeyCollection())
db.AddTable(tableName, table)
creationTime := time.Unix(0, 1667304000000001000).UTC()
_ = table.Insert(ctx, sql.NewRow("Jane Deo", "
[email protected]", types.MustJSON(`["556-565-566", "777-777-777"]`), creationTime))
_ = table.Insert(ctx, sql.NewRow("Jane Doe", "
[email protected]", types.MustJSON(`[]`), creationTime))
_ = table.Insert(ctx, sql.NewRow("John Doe", "
[email protected]", types.MustJSON(`["555-555-555"]`), creationTime))
_ = table.Insert(ctx, sql.NewRow("John Doe", "
[email protected]", types.MustJSON(`[]`), creationTime))
return pro
}
```
This example populates the database by creating `memory.Database` and
`memory.Table` objects via golang code, but you can also populate it
by issuing `CREATE DATABASE`, `CREATE TABLE`, etc. statements to the
server once it's running.
Once the server is running, connect with any MySQL client, including
the golang MySQL connector and the `mysql` shell.
```bash
> mysql --host=localhost --port=3306 --user=root mydb --execute="SELECT * FROM mytable;"
+----------+-------------------+-------------------------------+----------------------------+
| name | email | phone_numbers | created_at |
+----------+-------------------+-------------------------------+----------------------------+
| Jane Deo |
[email protected] | ["556-565-566","777-777-777"] | 2022-11-01 12:00:00.000001 |
| Jane Doe |
[email protected] | [] | 2022-11-01 12:00:00.000001 |
| John Doe |
[email protected] | ["555-555-555"] | 2022-11-01 12:00:00.000001 |
| John Doe |
[email protected] | [] | 2022-11-01 12:00:00.000001 |
+----------+-------------------+-------------------------------+----------------------------+
```
## Limitations of the in-memory database implementation
The in-memory database implementation included with this package is
intended for use in tests. It has specific limitations that we know
of:
- [Not
threadsafe](https://github.com/dolthub/go-mysql-server/issues/1306). To
avoid concurrency issues, limit DDL and DML statements (`CREATE
TABLE`, `INSERT`, etc.) to a single goroutine.
- [No transaction
support](https://github.com/dolthub/go-mysql-server/issues/1506). Statements
like `START TRANSACTION`, `ROLLBACK`, and `COMMIT` are no-ops.
- [Non-performant index
implementation](https://github.com/dolthub/go-mysql-server/issues/1347). Indexed
lookups and joins perform full table scans on the underlying tables.
## Custom backend implementations
You can create your own backend to query your own data sources by
implementing some interfaces. For detailed instructions, see the
[backend guide](./BACKEND.md).
## Technical documentation for contributors and backend developers
- [Architecture](./ARCHITECTURE.md) is an overview of the various
packages of the project and how they fit together.
- [Contribution guide](./CONTRIBUTING.md) for new contributors,
including instructions for how to get your PR merged.
## Powered by go-mysql-server
* [dolt](https://github.com/dolthub/dolt)
* [gitbase](https://github.com/src-d/gitbase) (defunct)
Are you building a database backend using **go-mysql-server**? We
would like to hear from you and include you in this list.
## Security Policy
[go-mysql-server's security
policy](https://github.com/dolthub/go-mysql-server/blob/main/SECURITY.md) is
maintained in this repository. Please follow the disclosure instructions there.
Please do not initially report security issues in this repository's public
GitHub issues.
## Acknowledgements
**go-mysql-server** was originally developed by the `{source-d}`
organzation, and this repository was originally forked from
[src-d](https://github.com/src-d/go-mysql-server). We want to thank
the entire `{source-d}` development team for their work on this
project, especially Miguel Molina (@erizocosmico) and Juanjo Álvarez
Martinez (@juanjux).
## License
Apache License 2.0, see [LICENSE](/LICENSE)
", Assign "at most 3 tags" to the expected json: {"id":"9240","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"