Go基础：用Go语言操作MySQL详解

一、MySQL数据库连接

Go语言操作MySQL是开发中常见的任务，通过Go语言的标准库database/sql和第三方MySQL驱动（如go-sql-driver/mysql），可以方便地实现数据库的连接、查询、插入、更新和删除等操作。

1.1 下载依赖

在Go语言中操作MySQL，首先需要安装MySQL驱动。常用的驱动是go-sql-driver/mysql，可以通过以下命令安装：

go get -u github.com/go-sql-driver/mysql

1.2 初始化连接

使用database/sql包和MySQL驱动初始化数据库连接。以下是一个简单的连接示例：

package main
import ("database/sql""fmt""log"_ "github.com/go-sql-driver/mysql"
)
func main() {// 数据库连接字符串dsn := "username:password@tcp(127.0.0.1:3306)/dbname?charset=utf8mb4&parseTime=True&loc=Local"db, err := sql.Open("mysql", dsn)if err != nil {log.Fatal("Failed to open database:", err)}defer db.Close()// 测试连接是否成功err = db.Ping()if err != nil {log.Fatal("Failed to connect to database:", err)}fmt.Println("Successfully connected to MySQL database!")
}

1.3 连接池配置

为了提高性能，可以配置数据库连接池：

db.SetMaxOpenConns(10) // 设置最大打开的连接数
db.SetMaxIdleConns(5)  // 设置最大空闲连接数

二、MySQL的CRUD操作

2.1 建库建表

在操作数据之前，首先需要创建数据库和表。以下是建表SQL语句示例：

CREATE DATABASE IF NOT EXISTS testdb;
USE testdb;
CREATE TABLE IF NOT EXISTS users (id INT AUTO_INCREMENT PRIMARY KEY,name VARCHAR(50) NOT NULL,age INT NOT NULL,created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

2.2 插入数据

使用Exec方法插入数据：

func insertUser(db *sql.DB, name string, age int) error {query := "INSERT INTO users (name, age) VALUES (?, ?)"_, err := db.Exec(query, name, age)if err != nil {return err}fmt.Println("User inserted successfully!")return nil
}

调用示例：

err := insertUser(db, "Alice", 25)
if err != nil {log.Fatal("Failed to insert user:", err)
}

2.3 查询数据

使用Query方法查询数据：

func queryUsers(db *sql.DB) error {query := "SELECT id, name, age FROM users"rows, err := db.Query(query)if err != nil {return err}defer rows.Close()fmt.Println("Users:")for rows.Next() {var id intvar name stringvar age intif err := rows.Scan(&id, &name, &age); err != nil {return err}fmt.Printf("ID: %d, Name: %s, Age: %d\n", id, name, age)}return nil
}

调用示例：

err := queryUsers(db)
if err != nil {log.Fatal("Failed to query users:", err)
}

2.4 更新数据

使用Exec方法更新数据：

func updateUser(db *sql.DB, id int, newName string, newAge int) error {query := "UPDATE users SET name = ?, age = ? WHERE id = ?"_, err := db.Exec(query, newName, newAge, id)if err != nil {return err}fmt.Println("User updated successfully!")return nil
}

调用示例：

err := updateUser(db, 1, "Bob", 30)
if err != nil {log.Fatal("Failed to update user:", err)
}

2.5 删除数据

使用Exec方法删除数据：

func deleteUser(db *sql.DB, id int) error {query := "DELETE FROM users WHERE id = ?"_, err := db.Exec(query, id)if err != nil {return err}fmt.Println("User deleted successfully!")return nil
}

调用示例：

err := deleteUser(db, 1)
if err != nil {log.Fatal("Failed to delete user:", err)
}

三、完整代码案例

以下是一个完整的Go语言操作MySQL的示例代码，包含连接、插入、查询、更新和删除操作：

package main
import ("database/sql""fmt""log"_ "github.com/go-sql-driver/mysql"
)
func main() {dsn := "username:password@tcp(127.0.0.1:3306)/testdb?charset=utf8mb4&parseTime=True&loc=Local"db, err := sql.Open("mysql", dsn)if err != nil {log.Fatal("Failed to open database:", err)}defer db.Close()err = db.Ping()if err != nil {log.Fatal("Failed to connect to database:", err)}fmt.Println("Successfully connected to MySQL database!")// 插入数据err = insertUser(db, "Alice", 25)if err != nil {log.Fatal("Failed to insert user:", err)}// 查询数据err = queryUsers(db)if err != nil {log.Fatal("Failed to query users:", err)}// 更新数据err = updateUser(db, 1, "Bob", 30)if err != nil {log.Fatal("Failed to update user:", err)}// 查询更新后的数据err = queryUsers(db)if err != nil {log.Fatal("Failed to query users:", err)}// 删除数据err = deleteUser(db, 1)if err != nil {log.Fatal("Failed to delete user:", err)}// 查询删除后的数据err = queryUsers(db)if err != nil {log.Fatal("Failed to query users:", err)}
}
func insertUser(db *sql.DB, name string, age int) error {query := "INSERT INTO users (name, age) VALUES (?, ?)"_, err := db.Exec(query, name, age)if err != nil {return err}fmt.Println("User inserted successfully!")return nil
}
func queryUsers(db *sql.DB) error {query := "SELECT id, name, age FROM users"rows, err := db.Query(query)if err != nil {return err}defer rows.Close()fmt.Println("Users:")for rows.Next() {var id intvar name stringvar age intif err := rows.Scan(&id, &name, &age); err != nil {return err}fmt.Printf("ID: %d, Name: %s, Age: %d\n", id, name, age)}return nil
}
func updateUser(db *sql.DB, id int, newName string, newAge int) error {query := "UPDATE users SET name = ?, age = ? WHERE id = ?"_, err := db.Exec(query, newName, newAge, id)if err != nil {return err}fmt.Println("User updated successfully!")return nil
}
func deleteUser(db *sql.DB, id int) error {query := "DELETE FROM users WHERE id = ?"_, err := db.Exec(query, id)if err != nil {return err}fmt.Println("User deleted successfully!")return nil
}

总结：Go语言通过database/sql包和MySQL驱动，提供了强大的数据库操作能力。本文详细介绍了MySQL的连接、插入、查询、更新和删除操作，并提供了完整的代码示例。