go-mysql-server 新版本发布

go-mysql-server 是在原有的基础上进行可增强，2021 q1版本实现了好多新的特性
如果结合以前的版本，triger 是一个很不错的特性，优化点也是很多的，很值得学习下
同时记得以前有写过与pg fdw 集成的，使用go-mysql-server或者一个基于mysql 的db
引擎，实现一些特殊业务操作还是很不错的

参考pdw 集成

• server 代码

package main

 

import (

    sqle "github.com/dolthub/go-mysql-server"

    "github.com/dolthub/go-mysql-server/auth"

    "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/information_schema"

)

 

 

func main() {

    engine := sqle.NewDefault()

    engine.AddDatabase(createTestDatabase())

    engine.AddDatabase(information_schema.NewInformationSchemaDatabase(engine.Catalog))

 

    config := server.Config{

        Protocol: "tcp",

        Address:  "0.0.0.0:3306",

        Auth:     auth.NewNativeSingle("root", "dalong", auth.AllPermissions),

    }

 

    s, err := server.NewDefaultServer(config, engine)

    if err != nil {

        panic(err)

    }

 

    s.Start()

}

 

func createTestDatabase() *memory.Database {

    const (

        dbName    = "mydb"

        tableName = "mytable"

    )

 

    db := memory.NewDatabase(dbName)

    table := memory.NewTable(tableName, sql.Schema{

        {Name: "name", Type: sql.Text, Nullable: false, Source: tableName},

        {Name: "email", Type: sql.Text, Nullable: false, Source: tableName},

    })

 

    db.AddTable(tableName, table)

    ctx := sql.NewEmptyContext()

    table.Insert(ctx, sql.NewRow("John Doe", "john@doe.com"))

    table.Insert(ctx, sql.NewRow("John Doe", "johnalt@doe.com"))

    table.Insert(ctx, sql.NewRow("Jane Doe", "jane@doe.com"))

    table.Insert(ctx, sql.NewRow("Evil Bob", "evilbob@gmail.com"))

    return db

}

 

• pdw 命令

CREATE EXTENSION mysql_fdw;

 

CREATE SERVER mysql_server

FOREIGN DATA WRAPPER mysql_fdw

OPTIONS (host '192.168.0.102', port '3306');

 

CREATE USER MAPPING FOR postgres

SERVER mysql_server

OPTIONS (username 'root', password 'dalong');

 

CREATE FOREIGN TABLE mydemo

(

    name text,

    email text

)

SERVER mysql_server

OPTIONS (dbname 'mydb', table_name 'mytable');

select name,count(*) from mydemo group by name;

 

trigger 使用

create table a (x int primary key)

create trigger a1 before insert on a for each row set new.x = new.x + 1

参考资料

https://github.com/dolthub/go-mysql-server/releases
https://www.cnblogs.com/rongfengliang/p/14021349.html
https://sourcegraph.com/github.com/dolthub/go-mysql-server/-/blob/enginetest/memory_engine_test.go#L119