343 lines
7.1 KiB
Go
343 lines
7.1 KiB
Go
package main
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import (
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"database/sql"
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"fmt"
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"log"
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"time"
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_ "modernc.org/sqlite"
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)
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// 用户模型
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type User struct {
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ID int
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Name string
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Email string
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Age int
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CreatedAt time.Time
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}
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// 数据库连接
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var db *sql.DB
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func main() {
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var err error
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// 1. 初始化数据库连接
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db, err = initDatabase("test.db")
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if err != nil {
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log.Fatal("初始化数据库失败:", err)
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}
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defer db.Close()
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fmt.Println("SQLite数据库CRUD示例")
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fmt.Println("====================")
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//// 2. 创建用户表
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//err = createTable()
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//if err != nil {
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// log.Fatal("创建表失败:", err)
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//}
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//fmt.Println("✓ 用户表创建成功")
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//
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//// 3. 创建用户
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//user1 := User{
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// Name: "张三",
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// Email: "zhangsan@example.com",
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// Age: 25,
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//}
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//
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//id, err := createUser(user1)
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//if err != nil {
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// log.Fatal("创建用户失败:", err)
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//}
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//fmt.Printf("✓ 创建用户成功，ID: %d\n", id)
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//
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user2 := User{
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Name: "李四",
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Email: "lisi@example.com",
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Age: 30,
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}
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id2, _ := createUser(user2)
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fmt.Printf("✓ 创建用户成功，ID: %d\n", id2)
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//// 4. 查询单个用户
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//fmt.Println("\n查询用户ID=1:")
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//user, err := getUserByID(1)
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//if err != nil {
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// log.Fatal("查询用户失败:", err)
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//}
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//printUser(user)
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// 5. 查询所有用户
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fmt.Println("\n查询所有用户:")
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users, err := getAllUsers()
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if err != nil {
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log.Fatal("查询所有用户失败:", err)
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}
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for _, u := range users {
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printUser(u)
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}
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//// 6. 更新用户
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//fmt.Println("\n更新用户ID=1的信息:")
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//updateData := map[string]interface{}{
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// "name": "张三丰",
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// "email": "zhangsanfeng@example.com",
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// "age": 28,
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//}
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//rowsAffected, err := updateUser(1, updateData)
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//if err != nil {
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// log.Fatal("更新用户失败:", err)
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//}
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//fmt.Printf("✓ 更新成功，影响行数: %d\n", rowsAffected)
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//
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//// 7. 再次查询验证更新
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//updatedUser, _ := getUserByID(1)
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//printUser(updatedUser)
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//
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//// 8. 删除用户
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//fmt.Println("\n删除用户ID=2:")
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//rowsAffected, err = deleteUser(2)
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//if err != nil {
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// log.Fatal("删除用户失败:", err)
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//}
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//fmt.Printf("✓ 删除成功，影响行数: %d\n", rowsAffected)
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//
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//// 9. 查询删除后的用户列表
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//fmt.Println("\n删除后的所有用户:")
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//remainingUsers, _ := getAllUsers()
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//if len(remainingUsers) == 0 {
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// fmt.Println("没有用户数据")
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//}
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//for _, u := range remainingUsers {
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// printUser(u)
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//}
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//
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//// 10. 批量插入示例
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//fmt.Println("\n批量插入用户:")
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//err = batchCreateUsers()
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//if err != nil {
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// log.Fatal("批量插入失败:", err)
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//}
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//
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//// 11. 分页查询示例
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//fmt.Println("\n分页查询（每页2条）:")
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//pageSize := 2
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//fmt.Println("第1页:")
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//page1Users, _ := getUsersByPage(1, pageSize)
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//for _, u := range page1Users {
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// printUser(u)
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//}
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//
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//fmt.Println("\n第2页:")
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//page2Users, _ := getUsersByPage(2, pageSize)
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//for _, u := range page2Users {
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// printUser(u)
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//}
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//
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//// 12. 统计用户数量
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//count, _ := countUsers()
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//fmt.Printf("\n用户总数: %d\n", count)
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}
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// 初始化数据库连接
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func initDatabase(dbPath string) (*sql.DB, error) {
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db, err := sql.Open("sqlite", dbPath)
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if err != nil {
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return nil, err
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}
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// 设置连接池参数
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db.SetMaxOpenConns(10)
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db.SetMaxIdleConns(5)
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db.SetConnMaxLifetime(5 * time.Minute)
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// 验证连接
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err = db.Ping()
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if err != nil {
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return nil, err
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}
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return db, nil
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}
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// 创建用户表
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func createTable() error {
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query := `
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CREATE TABLE IF NOT EXISTS users (
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id INTEGER PRIMARY KEY AUTOINCREMENT,
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name TEXT NOT NULL,
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email TEXT UNIQUE NOT NULL,
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age INTEGER,
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created_at DATETIME DEFAULT CURRENT_TIMESTAMP
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);
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CREATE INDEX IF NOT EXISTS idx_users_email ON users(email);
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CREATE INDEX IF NOT EXISTS idx_users_created_at ON users(created_at);
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`
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_, err := db.Exec(query)
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return err
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}
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// 创建用户（返回生成的ID）
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func createUser(user User) (int64, error) {
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query := `INSERT INTO users (name, email, age) VALUES (?, ?, ?)`
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result, err := db.Exec(query, user.Name, user.Email, user.Age)
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if err != nil {
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return 0, err
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}
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id, err := result.LastInsertId()
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if err != nil {
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return 0, err
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}
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return id, nil
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}
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// 根据ID查询用户
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func getUserByID(id int) (User, error) {
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var user User
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query := `SELECT id, name, email, age, created_at FROM users WHERE id = ?`
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row := db.QueryRow(query, id)
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err := row.Scan(&user.ID, &user.Name, &user.Email, &user.Age, &user.CreatedAt)
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if err != nil {
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return User{}, err
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}
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return user, nil
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}
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// 查询所有用户
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func getAllUsers() ([]User, error) {
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query := `SELECT id, name, email, age, created_at FROM users ORDER BY id`
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rows, err := db.Query(query)
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if err != nil {
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return nil, err
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}
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defer rows.Close()
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var users []User
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for rows.Next() {
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var user User
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err := rows.Scan(&user.ID, &user.Name, &user.Email, &user.Age, &user.CreatedAt)
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if err != nil {
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return nil, err
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}
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users = append(users, user)
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}
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return users, nil
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}
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// 更新用户
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func updateUser(id int, updates map[string]interface{}) (int64, error) {
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// 构建SQL语句
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query := "UPDATE users SET "
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args := []interface{}{}
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i := 0
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for key, value := range updates {
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if i > 0 {
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query += ", "
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}
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query += key + " = ?"
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args = append(args, value)
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i++
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}
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query += " WHERE id = ?"
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args = append(args, id)
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result, err := db.Exec(query, args...)
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if err != nil {
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return 0, err
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}
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return result.RowsAffected()
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}
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// 删除用户
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func deleteUser(id int) (int64, error) {
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query := `DELETE FROM users WHERE id = ?`
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result, err := db.Exec(query, id)
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if err != nil {
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return 0, err
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}
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return result.RowsAffected()
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}
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// 批量创建用户
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func batchCreateUsers() error {
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tx, err := db.Begin()
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if err != nil {
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return err
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}
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defer tx.Rollback()
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stmt, err := tx.Prepare("INSERT INTO users (name, email, age) VALUES (?, ?, ?)")
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if err != nil {
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return err
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}
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defer stmt.Close()
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users := []User{
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{Name: "王五", Email: "wangwu@example.com", Age: 22},
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{Name: "赵六", Email: "zhaoliu@example.com", Age: 35},
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{Name: "孙七", Email: "sunqi@example.com", Age: 28},
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}
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for _, user := range users {
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_, err := stmt.Exec(user.Name, user.Email, user.Age)
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if err != nil {
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return err
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}
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}
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return tx.Commit()
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}
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// 分页查询用户
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func getUsersByPage(page, pageSize int) ([]User, error) {
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offset := (page - 1) * pageSize
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query := `SELECT id, name, email, age, created_at FROM users
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ORDER BY id LIMIT ? OFFSET ?`
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rows, err := db.Query(query, pageSize, offset)
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if err != nil {
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return nil, err
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}
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defer rows.Close()
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var users []User
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for rows.Next() {
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var user User
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err := rows.Scan(&user.ID, &user.Name, &user.Email, &user.Age, &user.CreatedAt)
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if err != nil {
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return nil, err
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}
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users = append(users, user)
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}
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return users, nil
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}
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// 统计用户数量
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func countUsers() (int, error) {
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var count int
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query := `SELECT COUNT(*) FROM users`
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err := db.QueryRow(query).Scan(&count)
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return count, err
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}
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// 打印用户信息
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func printUser(user User) {
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fmt.Printf("ID: %d, 姓名: %s, 邮箱: %s, 年龄: %d, 创建时间: %s\n",
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user.ID, user.Name, user.Email, user.Age, user.CreatedAt.Format("2006-01-02 15:04:05"))
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}
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