Golang Gorm 高级查询之where + find

插入测试数据

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package mainimport ("fmt""gorm.io/driver/mysql""gorm.io/gorm"
)type Student struct {ID    int64Name  string `gorm:"size:6"`Age   intEmail *string
}func (*Student) TableName() string {return "student"
}func main() {dsn := "root:7PXjAkY!&nlR@tcp(192.168.11.128:3306)/test?charset=utf8mb4&parseTime=True&loc=Local"db, _ := gorm.Open(mysql.Open(dsn), &gorm.Config{})db.AutoMigrate(&Student{})var sList []Studentcount := db.Find(&sList).Delete(&sList).RowsAffectedfmt.Println("count=", count)email1 := "[e-mail]"sList = []Student{{ID:    1,Name:  "lucas",Age:   30,Email: &email1,},{ID:    2,Name:  "yanzi",Age:   28,Email: &email1,},{ID:    3,Name:  "lulei",Age:   29,Email: &email1,},{ID:    4,Name:  "jerry",Age:   25,Email: &email1,},}db.Create(&sList)}

 

where + first

---

user := User{}
// 查询用户数据
//自动生成sql： SELECT * FROM `users`  WHERE (username = 'tizi365') LIMIT 1db.Where("username = ?", "tizi365").First(&user)
fmt.Println(user)

 

Where语句里面条件    where + find = select * from table where...........

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其实就是sql语句当中的where 

	var sList []Studentdb.Debug().Where("name = ?", "lucas").Find(&sList)fmt.Println(sList)[0.746ms] [rows:1] SELECT * FROM `student` WHERE name = 'lucas'
[{1 lucas 30 0xc0001c91f0}] var s Studentdb.Debug().Where("name = ?", "yanzi").First(&s)fmt.Println(s)[1.263ms] [rows:1] SELECT * FROM `student` WHERE name = 'yanzi' ORDER BY `student`.`id` LIMIT 1
{2 yanzi 18 <nil>}

之前学的这种写法也是可以的 

	var s Studentdb.Debug().Find(&s, "name = ?", "lucas")fmt.Println(s)[1.552ms] [rows:1] SELECT * FROM `student` WHERE name = 'lucas'              
{1 lucas 30 0xc0001c9300}  

使用结构体查询

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如果是零值，那么查询的时候就不会将零值作为查询带上了 

	s = Student{Name: "lucas",Age:  30,}db.Debug().Where(&s).Find(&s)[1.543ms] [rows:1] SELECT * FROM `student` WHERE `student`.`name` = 'lucas' AND `student`.`age` = 30