优化字符串查找：内存映射 vs. 数据库查询

package main

import (
    "fmt"
    "time"
)

func main() {
    // 模拟从数据库加载数据
    data := []string{"apple", "banana", "cherry", "date", "elderberry"}

    // 创建一个Map
    stringMap := make(map[string]bool)

    // 将数据加载到Map
    for _, str := range data {
        stringMap[str] = true
    }

    // 查找字符串
    startTime := time.Now()
    target := "banana"
    exists := stringMap[target]
    endTime := time.Now()

    // 输出结果
    fmt.Printf("String '%s' exists: %v\n", target, exists)
    fmt.Printf("Lookup time: %v\n", endTime.Sub(startTime))
}

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql" // 导入MySQL驱动
    "time"
)

func main() {
    // 数据库连接信息
    dbUser := "your_user"
    dbPass := "your_password"
    dbHost := "your_host"
    dbName := "your_database"

    // 构建连接字符串
    dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s", dbUser, dbPass, dbHost, dbName)

    // 连接数据库
    db, err := sql.Open("mysql", dsn)
    if err != nil {
        panic(err.Error())
    }
    defer db.Close()

    // 测试连接
    err = db.Ping()
    if err != nil {
        panic(err.Error())
    }

    // 查找字符串
    startTime := time.Now()
    target := "banana"
    var exists bool
    err = db.QueryRow("SELECT EXISTS(SELECT 1 FROM your_table WHERE your_column = ?)", target).Scan(&exists)
    if err != nil {
        panic(err.Error())
    }
    endTime := time.Now()

    // 输出结果
    fmt.Printf("String '%s' exists: %v\n", target, exists)
    fmt.Printf("Lookup time: %v\n", endTime.Sub(startTime))
}