edgedb 基本试用

环境准备

使用docker-compose 运行

• docker-compose 文件

version: "3"
services:
  db:
    image: edgedb/edgedb
    ports:
    - "5656:5656"
    - "8888:8888"

基本数据库schema 操作

• 修改密码

  进入容器

按照提下提示操作
edgedb --admin alter role edgedb --password

• 创建数据库

CREATE DATABASE tutorial; 

• 连接创建的数据库

c tutorial

• 创建sdl

  数据库schema 定义语言

START TRANSACTION;

CREATE MIGRATION movies TO {
    type Movie {
        required property title -> str;
        # the year of release
        property year -> int64;
        required link director -> Person;
        multi link cast -> Person;
    }
    type Person {
        required property first_name -> str;
        required property last_name -> str;
    }
};


COMMIT MIGRATION movies;

COMMIT;

效果

START TRANSACTION;                                                                                                                         
START TRANSACTION
edgedb> CREATE MIGRATION movies TO { 
....... type Movie { 
....... required property title -> str; 
....... # the year of release 
....... property year -> int64; 
....... required link director -> Person; 
....... multi link cast -> Person; 
....... } 
....... type Person { 
....... required property first_name -> str; 
....... required property last_name -> str; 
....... } 
....... };                                                                                                                                         
CREATE MIGRATION
edgedb> COMMIT MIGRATION movies; 
.......                                                                                                                                            
COMMIT MIGRATION
edgedb> COMMIT;                                                                                                                                    
COMMIT TRANSACTION

• ddl

  可选的sdl 方式

CREATE TYPE Person {
    CREATE REQUIRED PROPERTY first_name -> str;
    CREATE REQUIRED PROPERTY last_name -> str;
};
CREATE TYPE Movie {
    CREATE REQUIRED PROPERTY title -> str;
    # the year of release
    CREATE PROPERTY year -> int64;
    CREATE REQUIRED LINK director -> Person;
    CREATE MULTI LINK cast -> Person;
};

EdgeQL查询语言

• 插入数据

INSERT Movie {
    title := 'Blade Runner 2049',
    year := 2017,
    director := (
        INSERT Person {
            first_name := 'Denis',
            last_name := 'Villeneuve',
        }
    ),
    cast := {
        (INSERT Person {
            first_name := 'Harrison',
            last_name := 'Ford',
        }),
        (INSERT Person {
            first_name := 'Ryan',
            last_name := 'Gosling',
        }),
        (INSERT Person {
            first_name := 'Ana',
            last_name := 'de Armas',
        }),
    }
};

效果

{Object { id: <uuid>'66807bcc-5e05-11e9-a37c-2fb9bd2b9a50' }}

• insert select 操作

INSERT Movie {
    title := 'Dune',
    director := (
        SELECT Person
        FILTER
            # the last name is sufficient
            # to identify the right person
            .last_name = 'Villeneuve'
    )
};

• select 操作

select Movie;

效果

select Movie; 
.......                                                                                                                                            
{
    Object { id: <uuid>'66807bcc-5e05-11e9-a37c-2fb9bd2b9a50' },
    Object { id: <uuid>'ae442d8c-5e05-11e9-a37c-cfe0a3967be9' }
}

• 查询指定字段数据

SELECT Movie {
    title,
    year
};

效果

SELECT Movie { 
....... title, 
....... year 
....... };                                                                                                                                         
{Object { title: 'Blade Runner 2049', year: 2017 }, Object { title: 'Dune', year: {} }}

• filter 操作

SELECT Movie {
    title,
    year
}
FILTER .title ILIKE 'blade runner%';

效果

SELECT Movie { 
....... title, 
....... year 
....... } 
....... FILTER .title ILIKE 'blade runner%';                                                                                                       
{Object { title: 'Blade Runner 2049', year: 2017 }}

• 数据类型修改

ALTER TYPE Person {
    ALTER PROPERTY first_name {
        DROP REQUIRED;
    }
};

graphql 查询

• 启动graphql

  注意需要在数据库中操作，先连接数据库 c tutorial

CONFIGURE SYSTEM INSERT Port {
    protocol := "graphql+http",
    database := "tutorial",
    address := "0.0.0.0",
    port := 8888,
    user := "http",
    concurrency := 4,
};

效果

tutorial> CONFIGURE SYSTEM INSERT Port { 
......... protocol := "graphql+http", 
......... database := "tutorial", 
......... address := "0.0.0.0", 
......... port := 8888, 
......... user := "http", 
......... concurrency := 4, 
......... };                                                                                                                                       
CONFIGURE SYSTEM

• 访问地址

http://localhost:8888/explore

• 操作

• graphql 查询

query {
  Movie {
    director {
      id
      last_name
      first_name
    }
    id
    cast {
      id
      last_name
      first_name
    }
    title
    year
  }
}

说明

edgedb schema 定义的地方以及查询上有好多地方和graphql 规范很相近，同时保留了sql 强大的能力，还是很不错的，但是目前的 
client sdk 还是有点少

参考资料

https://edgedb.com/docs/intro 
https://hub.docker.com/r/edgedb/edgedb 
https://github.com/edgedb/edgedb