72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
package main
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import (
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"fmt"
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"gorm.io/driver/sqlite"
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"gorm.io/gorm"
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)
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//type User struct {
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// ID uint `gorm:"primaryKey"`
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// Name string `gorm:"size:100"`
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// Orders []Order
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//}
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//
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//type Order struct {
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// ID uint `gorm:"primaryKey"`
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// UserID uint
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// Product string `gorm:"size:100"`
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// Amount int
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//}
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func main() {
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db, _ := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})
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db.AutoMigrate(&User{}, &Order{})
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//user := User{Name: "Alice"}
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//db.Create(&user)
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//查询用户根据名称
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var user User
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db.Where("name = ?", "Alice").First(&user)
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//order1 := Order{Product: "Laptop"}
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//order2 := Order{Product: "Mouse"}
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//order3 := Order{Product: "Keyboard"}
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// 1. Append - 添加关联
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//db.Model(&user).Association("Orders").Append(&order1, &order2)
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//fmt.Println("Orders appended")
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// 2. Count - 统计关联数量
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//count := db.Model(&user).Association("Orders").Count()
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//fmt.Printf("Order count: %d\n", count)
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// 4. Replace - 替换所有关联
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//db.Model(&user).Association("Orders").Replace(&order3)
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//查询订单 Keyboard
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var order3 Order
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db.Where("product = ?", "Keyboard").First(&order3)
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// 5. Delete - 删除关联（不删除记录本身）
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//db.Model(&user).Association("Orders").Delete(&order3)
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//fmt.Println("Association deleted")
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//fmt.Println("Orders replaced with Keyboard")
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// 6. Clear - 清空所有关联
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//db.Model(&user).Association("Orders").Append(&order3)
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db.Model(&user).Association("Orders").Clear()
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fmt.Println("All associations cleared")
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// 3. Find - 查找关联
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var orders []Order
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db.Model(&user).Association("Orders").Find(&orders)
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fmt.Println("Orders found:")
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for _, o := range orders {
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fmt.Printf(" - %s\n", o.Product)
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}
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}
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