go如何检查mysql数据库变化

package main

import (
    "database/sql"
    "fmt"
    "time"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "username:password@tcp(localhost:3306)/dbname")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    // 初始查询
    rows, err := db.Query("SELECT id, name FROM users")
    if err != nil {
        panic(err)
    }
    defer rows.Close()

    // 处理初始结果
    for rows.Next() {
        var id int
        var name string
        err = rows.Scan(&id, &name)
        if err != nil {
            panic(err)
        }
        fmt.Printf("Initial user: %d, %s\n", id, name)
    }

    // 轮询检查变化
    for {
        time.Sleep(5 * time.Second) // 每5秒检查一次
        rows, err := db.Query("SELECT id, name FROM users")
        if err != nil {
            panic(err)
        }

        // 处理新结果
        for rows.Next() {
            var id int
            var name string
            err = rows.Scan(&id, &name)
            if err != nil {
                panic(err)
            }
            fmt.Printf("Updated user: %d, %s\n", id, name)
        }

        rows.Close()
    }
}