查询

var user User
var users []User 
// 根据主键查询第一条记录
db.First(&user)
//// SELECT * FROM users ORDER BY id LIMIT 1;
// 随机获取一条记录
db.Take(&user)
//// SELECT * FROM users LIMIT 1;
// 根据主键查询最后一条记录
db.Last(&user)
//// SELECT * FROM users ORDER BY id DESC LIMIT 1;
// 查询所有的记录
db.Find(&users)
//// SELECT * FROM users;
// 查询指定的某条记录(仅当主键为整型时可用)
db.First(&user, 10)
//// SELECT * FROM users WHERE id = 10;

Where 条件

普通 SQL

// 获取第一个匹配的记录
db.Where("name = ?", "jinzhu").First(&user)
//// SELECT * FROM users WHERE name = 'jinzhu' limit 1;
// 获取所有匹配的记录
db.Where("name = ?", "jinzhu").Find(&users)
//// SELECT * FROM users WHERE name = 'jinzhu';
// <>
db.Where("name <> ?", "jinzhu").Find(&users)
//// SELECT * FROM users WHERE name <> 'jinzhu';
// IN
db.Where("name IN (?)", []string{"jinzhu", "jinzhu 2"}).Find(&users)
//// SELECT * FROM users WHERE name in ('jinzhu','jinzhu 2');
// LIKE
db.Where("name LIKE ?", "%jin%").Find(&users)
//// SELECT * FROM users WHERE name LIKE '%jin%';
// AND
db.Where("name = ? AND age >= ?", "jinzhu", "22").Find(&users)
//// SELECT * FROM users WHERE name = 'jinzhu' AND age >= 22;
// Time
db.Where("updated_at > ?", lastWeek).Find(&users)
//// SELECT * FROM users WHERE updated_at > '2000-01-01 00:00:00';
// BETWEEN
db.Where("created_at BETWEEN ? AND ?", lastWeek, today).Find(&users)
//// SELECT * FROM users WHERE created_at BETWEEN '2000-01-01 00:00:00' AND '2000-01-08 00:00:00';

Struct & Map

// Struct
db.Where(&User{Name: "jinzhu", Age: 20}).First(&user)
//// SELECT * FROM users WHERE name = "jinzhu" AND age = 20 ORDER BY id LIMIT 1;
// Map
db.Where(map[string]interface{}{"name": "jinzhu", "age": 20}).Find(&users)
//// SELECT * FROM users WHERE name = "jinzhu" AND age = 20;
// 主键切片
db.Where([]int64{20, 21, 22}).Find(&users)
//// SELECT * FROM users WHERE id IN (20, 21, 22);

提示 当通过结构体进行查询时，GORM将会只通过非零值字段查询，这意味着如果你的字段值为0，’’， false 或者其他 零值时，将不会被用于构建查询条件，例如：

db.Where(&User{Name: "jinzhu", Age: 0}).Find(&users)
//// SELECT * FROM users WHERE name = "jinzhu";

你可以使用指针或实现 Scanner/Valuer 接口来避免这个问题.

// 使用指针
type User struct {
  gorm.Model
  Name string
  Age  *int
}
// 使用 Scanner/Valuer
type User struct {
  gorm.Model
  Name string
  Age  sql.NullInt64  // sql.NullInt64 实现了 Scanner/Valuer 接口
}

Not 条件