数据库基本操作与gorm

create database test_db;
use test_db;
create table student(id int(10) auto_increment not null,name varchar(100),age tinyint unsigned,sex tinyint unsigned comment '1表示男，0 表示女',CONSTRAINT sex CHECK (sex in(0,1)) ,primary key (id));
insert into student( name, age, sex) value ('张三',18,1);insert into student( name, age, sex) value ('李四',18,1);insert into student( name, age, sex) value ('王五',18,1);insert into student( name, age, sex) value ('赵云',18,1);insert into student( name, age, sex) value ('张飞',18,1);insert into student( name, age, sex) value ('马超',18,1);insert into student( name, age, sex) value ('刘备',18,1);insert into student( name, age, sex) value ('关羽',18,1);insert into student( name, age, sex) value ('曹操',18,1);insert into student( name, age, sex) value ('貂蝉',18,0);insert into student( name, age, sex) value ('花木兰',18,0);
select * from student;delete from student where name like '%花%';
update student set age = age + 1;
select count(*) from student where sex=1;select count(*) from student where sex=0;

package main
import (  "fmt"  "github.com/jinzhu/gorm"  _ "github.com/jinzhu/gorm/dialects/mysql"  "log")
type User struct {  ID       int64  Name     string `gorm:"default:'vip用户'"`  Age      uint   `gorm:"default:0"`  IsActive bool   `gorm:"default:false"`}
func main() {  db, err := gorm.Open("mysql", "root:123456@(127.0.0.1:3306)/db1?charset=utf8mb4&parseTime=True&loc=Local")  if err != nil {    panic(err)  }
  defer func() {    db.Close()    log.Println("close connection with mysql server")  }()
  db.AutoMigrate(&User{})
  user := User{    Name:     "jack",    Age:      18,    IsActive: true,  } //不给值，都默认为对应数据类型的零值  db.Create(&user)  var u = new(User)  fmt.Printf("%#v\n", u)  var uu User  db.Find(&uu, "Name=?", "jack")  fmt.Printf("%#v\n", uu)  db.Model(&u).Update("Age", 19)  db.Delete(&u)}
/*&main.User{ID:0, Name:"", Age:0x0, IsActive:false}main.User{ID:9, Name:"jack", Age:0x12, IsActive:true}2022/02/17 22:40:04 close connection with mysql server
*/