012-Go ORM框架之Gorm测试

1：参考：https://github.com/jinzhu/gorm

2：数据库脚本（pg）

--
create table posts(
    id            serial primary key,
    content        text,
    author        varchar(100),
    create_time    timestamptz
);

create table comments(
    id            serial primary key,
    content        text,
    author        varchar(100),
    post_id        int references posts(id),
    create_time    timestamptz
);

3：posts.go

package posts

import(
        "fmt"
        "github.com/jinzhu/gorm"
        _"github.com/lib/pq"
        "time"
)


type Comment struct{
        ID                      int             
        Content         string          `sql:"not null"`
        Author          string          `sql:"not null"`
        PostId          int             `sql:"post_id"`
        CreateTime      time.Time       `sql:"create_time"`
}

type Post struct{
        ID                      int             
        Content         string          `sql:"not null"`
        Author          string          `sql:"not null"`
        CreateTime      time.Time       `sql:"create_time"`
        Comments        []Comment
}


const(
    host = "192.168.72.128"
    port = 5432
    user = "test"
    password = "test"
    dbname = "testdb"
)

var Db *gorm.DB

func init(){
        var err error
        
        psqlInfo := fmt.Sprintf("host=%s port=%d user=%s "+
                "password=%s dbname=%s sslmode=disable",host, port, user, password, dbname)

        Db, err = gorm.Open("postgres", psqlInfo)
        if err != nil{
                panic(err)
        }

        Db.AutoMigrate(&Post{}, &Comment{})
}

func (post *Post) CreatePost() error{
        return Db.Create(post).Error
}

func (comment *Comment) CreateComment(post *Post) error{
        return Db.Model(post).Association("Comments").Append(comment).Error
}

func (post *Post) GetComments() (comments []Comment, err error){
        Db.Where("author=$1", "王五").First(post)
        err = Db.Model(&post).Related(&comments).Error
        return
}

　4：main.go

package main

import(
        "fmt"
        "time"
        "Chapter02/posts"
)

func main(){
        post := posts.Post{
                Content:"Hello go!",
                Author:"王五",
                CreateTime:     time.Now(),
        }

        fmt.Println(post)

        err := post.CreatePost()
        if err!=nil{
                panic(err)
        }
        fmt.Println(post)

        comment := posts.Comment{
                Content:"不错哟",
                Author:"小二",
                CreateTime:     time.Now(),
        }
        err = comment.CreateComment(&post)
        if err != nil{
                panic(err)
        }

        post = posts.Post{}
        comments, err := post.GetComments()
        if err != nil{
                panic(err)
        }
        for _,p :=  range comments{
                fmt.Printf("%s-%s\n", p.Author,p.Content)
        }
}