まずMySQLにデータを作ります。
mysql
create database go;
use go
create table users (
id int auto_increment primary key,
name varchar(255),
age int,
address varchar(255),
update_at datetime
);
mysql> describe users;
+———–+————–+——+—–+———+—————-+
| Field | Type | Null | Key | Default | Extra |
+———–+————–+——+—–+———+—————-+
| id | int | NO | PRI | NULL | auto_increment |
| name | varchar(255) | YES | | NULL | |
| age | int | YES | | NULL | |
| address | varchar(255) | YES | | NULL | |
| update_at | datetime | YES | | NULL | |
+———–+————–+——+—–+———+—————-+
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
)
func main(){
_, err := sqlConnect()
if err != nil {
panic(err.Error())
} else {
fmt.Println("DB connect success!")
}
}
func sqlConnect()(database *gorm.DB, err error){
DBMS := "mysql"
USER := "hoge"
PASS := "fuga"
PROTOCOL := "tcp(localhost:3306)"
DBNAME := "go"
CONNECT := USER + ":" + PASS + "@" + PROTOCOL + "/" + DBNAME + "?charset=utf8&parseTime=true&loc=Asia%2FTokyo"
return gorm.Open(DBMS, CONNECT)
}
$ /home/vagrant/go/bin/dep ensure
$ go run main.go
DB connect success!
### データ挿入
import (
"fmt"
"time"
_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
)
func main(){
db, err := sqlConnect()
if err != nil {
panic(err.Error())
}
defer db.Close()
error := db.Create(&Users{
Name: "山田太郎",
Age: 20,
Address: "東京都港区赤坂1丁目1-1",
UpdateAt: getDate(),
}).Error
if error != nil {
fmt.Println(error)
} else {
fmt.Println("data insert success!")
}
}
func sqlConnect()(database *gorm.DB, err error){
DBMS := "mysql"
USER := "hoge"
PASS := "fuga"
PROTOCOL := "tcp(localhost:3306)"
DBNAME := "go"
CONNECT := USER + ":" + PASS + "@" + PROTOCOL + "/" + DBNAME + "?charset=utf8&parseTime=true&loc=Asia%2FTokyo"
return gorm.Open(DBMS, CONNECT)
}
type Users struct {
ID int
Name string `json:"name"`
Age int `json:"age"`
Address string `json:"address"`
UpdateAt string `json:"updateAt" sql:"not null;type:date"`
}
func getDate() string {
const layout = "2006-01-01 15:05:30"
now := time.Now()
return now.Format(layout)
}
$ go run main.go
data insert success!
mysql> select * from users;
+—-+————–+——+———————————+———————+
| id | name | age | address | update_at |
+—-+————–+——+———————————+———————+
| 1 | 山田太郎 | 20 | 東京都港区赤坂1丁目1-1 | 2021-09-09 14:23:20 |
+—-+————–+——+———————————+———————+
1 row in set (0.00 sec)
### データの取得
func main(){
db, err := sqlConnect()
if err != nil {
panic(err.Error())
}
defer db.Close()
result := []*Users{}
error := db.Find(&result).Error
if error != nil || len(result) == 0 {
return
}
for _, user := range result {
fmt.Println(user.Name)
}
}
$ go run main.go
山田太郎
### データの更新
func main(){
db, err := sqlConnect()
if err != nil {
panic(err.Error())
}
defer db.Close()
result := []*Users{}
error := db.Find(&result).Error
if error != nil || len(result) == 0 {
return
}
for _, user := range result {
fmt.Println(user.Name)
}
fmt.Println("update")
error = db.Model(Users{}).Where("id = ?", 1).Update(&Users{
Name: "佐藤はじめ",
UpdateAt: getDate(),
}).Error
if error != nil {
fmt.Println(error)
}
result = []*Users{}
db.Find(&result)
for _, user := range result {
fmt.Println(user.Name)
}
}
$ go run main.go
山田太郎
update
佐藤はじめ
### DELETE
fmt.Println("Delete")
error = db.Where("id = ?", 1).Delete(Users{}).Error
if error != nil {
fmt.Println(error)
}
result = []*Users{}
db.Find(&result)
for _, user := range result {
fmt.Println(user.Name)
}
$ go run main.go
佐藤はじめ
Delete
mysql> select * from users;
Empty set (0.00 sec)
OK、CRUDは一通りわかった🈴
