/
main.go
97 lines (83 loc) · 2.45 KB
/
main.go
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package main
import (
"fmt"
"log"
"github.com/spf13/pflag"
"gorm.io/driver/mysql"
"gorm.io/gorm"
)
type Product struct {
gorm.Model
Code string `gorm:"column:code"`
Price uint `gorm:"column:price"`
}
// TableName maps to mysql table name.
func (p *Product) TableName() string {
return "product"
}
var (
host = pflag.StringP("host", "H", "127.0.0.1:3306", "MySQL service host address")
username = pflag.StringP("username", "u", "root", "Username for access to mysql service")
password = pflag.StringP("password", "p", "root", "Password for access to mysql, should be used pair with password")
database = pflag.StringP("database", "d", "test", "Database name to use")
help = pflag.BoolP("help", "h", false, "Print this help message")
)
func main() {
// Parse command line flags
pflag.CommandLine.SortFlags = false
pflag.Usage = func() {
pflag.PrintDefaults()
}
pflag.Parse()
if *help {
pflag.Usage()
return
}
dns := fmt.Sprintf(`%s:%s@tcp(%s)/%s?charset=utf8&parseTime=%t&loc=%s`,
*username,
*password,
*host,
*database,
true,
"Local")
db, err := gorm.Open(mysql.Open(dns), &gorm.Config{})
if err != nil {
panic("failed to connect database")
}
// 1. Auto migration for given models
db.AutoMigrate(&Product{})
// 2. Insert the value into database
if err := db.Create(&Product{Code: "D42", Price: 100}).Error; err != nil {
log.Fatalf("Create error: %v", err)
}
PrintProducts(db)
// 3. Find first record that match given conditions
product := &Product{}
if err := db.Where("code= ?", "D42").First(&product).Error; err != nil {
log.Fatalf("Get product error: %v", err)
}
// 4. Update value in database, if the value doesn't have primary key, will insert it
product.Price = 200
if err := db.Save(product).Error; err != nil {
log.Fatalf("Update product error: %v", err)
}
PrintProducts(db)
// 5. Delete value match given conditions
if err := db.Where("code = ?", "D42").Delete(&Product{}).Error; err != nil {
log.Fatalf("Delete product error: %v", err)
}
PrintProducts(db)
}
// List products
func PrintProducts(db *gorm.DB) {
products := make([]*Product, 0)
var count int64
d := db.Where("code like ?", "%D%").Offset(0).Limit(2).Order("id desc").Find(&products).Offset(-1).Limit(-1).Count(&count)
if d.Error != nil {
log.Fatalf("List products error: %v", d.Error)
}
log.Printf("totalcount: %d", count)
for _, product := range products {
log.Printf("\tcode: %s, price: %d\n", product.Code, product.Price)
}
}