MySQL 索引与 SQL 优化实战：让查询从分钟级降到毫秒级

# 更新软件包列表（apt 必须先做这一步，否则会报"找不到软件包"）
sudo apt update

# 安装 MySQL 服务器（默认会装最新版，当前最新稳定版为 8.0.x）
sudo apt install -y mysql-server

# 启动并设置开机自启
sudo systemctl start mysql
sudo systemctl enable mysql

# 检查运行状态
sudo systemctl status mysql

# CentOS 8+/RHEL 8+ 使用 dnf（yum 已逐渐被替代）
sudo dnf install -y mysql-server

# 启动
sudo systemctl start mysqld
sudo systemctl enable mysqld
sudo systemctl status mysqld

# 用 Homebrew 安装（没有 Homebrew 的先跑：/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"）
brew install mysql
brew services start mysql

# 交互式安全向导：设置 root 密码、删除匿名账号、禁止 root 远程登录等
sudo mysql_secure_installation

# 以 root 用户登录（首次无密码直接回车，之后需要输入上面设置的密码）
mysql -u root -p

-- 创建一个名为 shop 的数据库（UTF-8 编码，支持中文）
CREATE DATABASE shop DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- 切换到 shop 数据库
USE shop;

-- ==============================
-- 表1：用户表（users）
-- ==============================
CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '主键自增 ID',
    username VARCHAR(50) NOT NULL UNIQUE COMMENT '用户名，不能重复也不能为空',
    email VARCHAR(100) NOT NULL COMMENT '邮箱',
    phone VARCHAR(20) COMMENT '手机号（允许为空，有些用户不设）',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间，自动生成'
) ENGINE=InnoDB COMMENT='用户表';

-- 插入几条测试数据
INSERT INTO users (username, email) VALUES
('alice', '[email protected]'),
('bob', '[email protected]'),
('charlie', '[email protected]');

-- ==============================
-- 表2：商品表（products）
-- ==============================
CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '主键自增 ID',
    name VARCHAR(200) NOT NULL COMMENT '商品名称',
    price DECIMAL(10, 2) NOT NULL COMMENT '价格，精确到分（10位总长度，小数占2位）',
    stock INT DEFAULT 0 COMMENT '库存量，默认为 0',
    category VARCHAR(50) COMMENT '分类',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间'
) ENGINE=InnoDB COMMENT='商品表';

INSERT INTO products (name, price, stock, category) VALUES
('机械键盘', 399.00, 50, '数码'),
('无线鼠标', 89.90, 200, '数码'),
('Python 入门教程', 49.00, 1000, '图书'),
('咖啡杯', 35.00, 300, '生活');

-- ==============================
-- 表3：订单表（orders）
-- ==============================
CREATE TABLE orders (
    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '订单 ID',
    user_id INT NOT NULL COMMENT '关联用户表的 id（外键）',
    product_id INT NOT NULL COMMENT '关联商品表的 id（外键）',
    quantity INT NOT NULL DEFAULT 1 COMMENT '购买数量',
    order_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '下单时间',
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE COMMENT '外键约束：用户删除时级联删其订单',
    FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE RESTRICT COMMENT '外键约束：有订单引用此商品时不允许删除'
) ENGINE=InnoDB COMMENT='订单表';

INSERT INTO orders (user_id, product_id, quantity) VALUES
(1, 1, 1),   -- alice 买了机械键盘 x1
(1, 3, 2),   -- alice 买了 Python 教程 x2
(2, 2, 3);   -- bob 买了无线鼠标 x3

-- 联合查询：查看 alice 的所有订单及商品信息
SELECT u.username, p.name, o.quantity, o.order_time
FROM users u
JOIN orders o ON u.id = o.user_id
JOIN products p ON o.product_id = p.id
WHERE u.username = 'alice';

-- ===== 方法1：建表时直接定义索引 =====
CREATE INDEX idx_username ON users(username);
-- 在 users 表的 username 列上创建了普通索引

-- ===== 方法2：ALTER TABLE 为已有表加索引 =====
ALTER TABLE products ADD INDEX idx_category (category);
-- 为已有的 products 表加了一个分类索引

-- ===== 方法3：唯一索引（比普通索引多一层"不能重复"的约束）=====
CREATE UNIQUE INDEX idx_email ON users(email);
-- 保证 email 列不会有两行相同的值
-- 也可以在建表时用 CONSTRAINT 语法：ALTER TABLE users ADD UNIQUE(unixx_IX_index_name email);
-- ALTER TABLE tbl_name ADD UNIQUE index_name (column_list);
ALTER TABLE users ADD UNIQUE INDEX idx_email_unique (email);

-- ===== 查看某张表有哪些索引 =====
SHOW INDEX FROM users;
-- 输出会显示索引名、列名、是否唯一、索引类型等信息

-- ===== 联合索引（多列一起建索引）=====
ALTER TABLE orders ADD INDEX idx_user_time (user_id, order_time);
-- 先按 user_id 排，相同 user_id 再按 order_time 排
-- 这叫做最左前缀原则：只 WHERE user_id 能用索引，只 WHERE order_time 则不能用（因为没走在最左边）

-- 删除不再需要的索引
DROP INDEX idx_category ON products;
-- 或者
ALTER TABLE products DROP INDEX idx_category;

-- 删除主键（先取消 AUTO_INCREMENT 再删）
ALTER TABLE users MODIFY id INT NOT NULL;
ALTER TABLE users DROP PRIMARY KEY;

-- 用法：在 SELECT 前面加上 EXPLAIN 即可
EXPLAIN SELECT * FROM users WHERE username = 'alice';

-- 批量插入 10000 条测试数据（在 MySQL 命令行里这样跑）
DELIMITER //
CREATE PROCEDURE insert_test_data()
BEGIN
    DECLARE i INT DEFAULT 1;
    WHILE i <= 10000 DO
        INSERT INTO orders (user_id, product_id, quantity)
        VALUES ((i % 3) + 1, ((i % 4) + 1), (i % 10) + 1);
        SET i = i + 1;
    END WHILE;
END //
DELIMITER ;

CALL insert_test_data();
DROP PROCEDURE insert_test_data;

EXPLAIN SELECT * FROM users WHERE email LIKE '%alice%' \G

EXPLAIN SELECT * FROM users WHERE username = 'alice' \G

-- 查看当前慢查询阈值（单位：秒，默认 10 秒）
SHOW VARIABLES LIKE 'long_query_time';

-- 设置为 1 秒（生产环境建议 1~2 秒，开发阶段可设 0.5 秒抓更多数据）
SET GLOBAL long_query_time = 1;

-- 查看慢查询日志文件路径
SHOW VARIABLES LIKE 'slow_query_log_file';

-- 确认慢查询日志是否开启
SHOW VARIABLES LIKE 'slow_query_log';

-- 如果未开启，手动开启
SET GLOBAL slow_query_log = 'ON';

-- （可选）同时记录没有用到索引的查询——帮你发现"忘了加索引"的 SQL
SET GLOBAL log_queries_not_using_indexes = 1;

# 实时监控慢查询日志
sudo tail -f /var/log/mysql/slow.log

# 按查询次数排序，只看 Top 10
mysqldumpslow -s c -t 10 /var/log/mysql/slow.log

# 按平均耗时排序，Top 10
mysqldumpslow -s t -t 10 /var/log/mysql/slow.log

# 只看含有"ORDER BY"的慢查询
mysqldumpslow -s t -t 10 -g "order by" /var/log/mysql/slow.log

-- 方法1：显式开启事务
START TRANSACTION;
-- 或等价写法
BEGIN;

-- 一系列操作...
UPDATE accounts SET balance = balance - 100 WHERE user_id = 1;
UPDATE accounts SET balance = balance + 100 WHERE user_id = 2;

-- 检查无误后提交（永久的写入磁盘）
COMMIT;

-- ---- 如果发现有问题，回滚（撤销所有未提交的修改）----

START TRANSACTION;
UPDATE accounts SET balance = balance - 100 WHERE user_id = 1;
-- 哎呀，刚手滑多减了，赶紧撤回！
ROLLBACK;
-- 此时 user_id=1 的余额已经恢复原样了

START TRANSACTION;
INSERT INTO users (username, email) VALUES ('test1', '[email protected]');
SAVEPOINT sp1;                              -- 打个标记

INSERT INTO users (username, email) VALUES ('test2', '[email protected]');
ROLLBACK TO SAVEPOINT sp1;                  -- 只回滚到 sp1，test2 被丢弃，test1 保留
-- 释放保存点（可选）
RELEASE SAVEPOINT sp1;

-- 查看当前会话的隔离级别
SELECT @@transaction_isolation;

-- 查看全局隔离级别
SELECT @@global.transaction_isolation;

-- 设置当前会话的隔离级别
SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;

-- 设置全局隔离级别（影响新建连接，需 SUPER 权限）
SET GLOBAL TRANSACTION ISOLATION LEVEL REPEATABLE READ;

#!/usr/bin/env bash
set -u
# ============================================================
#  MySQL 索引与 SQL 优化实战 — 一键安装脚本（macOS / Linux / WSL）
#  公开源码，欢迎审查 —— 不放心可先复制给 AI 判断
# ============================================================

GREEN='\033[0;32m'; YELLOW='\033[1;33m'; RED='\033[0;31m'; CYAN='\033[0;36m'; NC='\033[0m'
info()  { echo -e "${GREEN}[INFO]${NC} $1"; }
warn()  { echo -e "${YELLOW}[WARN]${NC} $1"; }
error() { echo -e "${RED}[ERROR]${NC} $1"; }
step()  { echo -e "${CYAN}[STEP]${NC} $1"; }

detect_network() {
  step "检测网络环境（国内 / 国外）..."
  if curl -fsI --max-time 5 "https://claude.ai" >/dev/null 2>&1; then
    info "可直连 claude.ai，判定为海外网络"
    echo "overseas"
  else
    warn "无法直连 claude.ai，判定为国内网络环境（将使用国内镜像源）"
    echo "domestic"
  fi
}

get_os() {
  if [ -f /etc/os-release ]; then
    . /etc/os-release
    echo "$ID"
  elif command -v sw_vers >/dev/null 2>&1; then
    echo "darwin"
  else
    echo "unknown"
  fi
}

detect_os() {
  step "检测操作系统..."
  local os_id
  os_id=$(get_os)
  if [ "$os_id" = "darwin" ]; then
    info "检测到 macOS"
    echo "macos"
  elif [ "$os_id" = "debian" ] || [ "$os_id" = "ubuntu" ]; then
    info "检测到 Debian / Ubuntu"
    echo "debian"
  elif [ "$os_id" = "centos" ] || [ "$os_id" = "rhel" ] || [ "$os_id" = "fedora" ]; then
    info "检测到 CentOS / RHEL / Fedora"
    echo "redhat"
  elif [ "$os_id" = "alpine" ]; then
    info "检测到 Alpine Linux"
    echo "alpine"
  else
    warn "未知发行版，尝试使用 apt 安装"
    echo "debian"
  fi
}

check_mysql_running() {
  if command -v mysql >/dev/null 2>&1; then
    if mysql -u root -e "SELECT 1;" >/dev/null 2>&1; then
      info "MySQL 已安装并正在运行"
      return 0
    fi
  fi
  return 1
}

install_on_debian() {
  local net="$1"
  step "安装 MySQL Server（Debian/Ubuntu 系）..."

  if [ "$net" = "domestic" ]; then
    warn "国内网络，尝试使用 apt 默认源（如超时请手动更换清华源）..."
  fi

  if sudo apt-get update --allow-releaseinfo-change -o Dir::Etc::sourcelist="null" -o Dir::Etc::sourceparts="-" >/dev/null 2>&1 || true; then
    :
  fi

  if sudo DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server >/dev/null 2>&1; then
    info "MySQL 安装成功"
    return 0
  fi

  warn "apt 安装失败，尝试 MariaDB（MySQL 的兼容替代品，功能一致）..."
  if sudo DEBIAN_FRONTEND=noninteractive apt-get install -y mariadb-server >/dev/null 2>&1; then
    info "MariaDB 安装成功（功能与 MySQL 高度兼容）"
    return 0
  fi

  error "MySQL/MariaDB 安装失败。"
  echo "  请手动尝试：sudo apt install -y mysql-server"
  echo "  或换清华源后重试：sudo sed -i 's/archive.ubuntu.com/mirrors.tuna.tsinghua.edu.cn/g' /etc/apt/sources.list"
  return 1
}

install_on_redhat() {
  step "安装 MySQL Server（CentOS/RHEL 系）..."

  if sudo dnf install -y mysql-server 2>/dev/null; then
    info "MySQL 安装成功"
    return 0
  fi

  warn "dnf 安装失败，尝试 yum..."
  if sudo yum install -y mysql-server 2>/dev/null; then
    info "MySQL 安装成功（yum）"
    return 0
  fi

  warn "MySQL 安装失败，尝试 MariaDB..."
  if sudo dnf install -y mariadb-server 2>/dev/null; then
    info "MariaDB 安装成功"
    return 0
  fi

  error "MySQL/MariaDB 安装失败。请手动安装：sudo dnf install -y mysql-server"
  return 1
}

install_on_macos() {
  step "安装 MySQL（macOS）..."

  if command -v brew >/dev/null 2>&1; then
    if brew install mysql >/dev/null 2>&1; then
      info "MySQL 安装成功"
      brew services start mysql >/dev/null 2>&1
      return 0
    fi
  fi

  error "Homebrew 不可用或安装失败。"
  echo "  请先安装 Homebrew：/bin/bash -c \"\$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)\""
  echo "  或使用 ghfast.top 代理加速安装脚本（国内）："
  echo "    /bin/bash -c \"\$(curl -fsSL https://ghfast.top/https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)\""
  return 1
}

install_on_alpine() {
  step "安装 MySQL/MariaDB（Alpine Linux）..."

  if apk add --no-cache mariadb mariadb-server >/dev/null 2>&1; then
    info "MariaDB 安装成功"
    return 0
  fi

  error "Alpine 安装失败。请手动：apk add --no-cache mariadb mariadb-server && rc-update add mariadbd && rc-start mariadbd"
  return 1
}

start_mysql() {
  step "启动 MySQL 服务..."

  if command -v systemctl >/dev/null 2>&1; then
    sudo systemctl enable mysql 2>/dev/null || sudo systemctl enable mysqld 2>/dev/null || true
    sudo systemctl start mysql 2>/dev/null || sudo systemctl start mysqld 2>/dev/null || true
  elif command -v brew >/dev/null 2>&1; then
    brew services start mysql 2>/dev/null || true
  fi

  sleep 2
  if command -v mysql >/dev/null 2>&1 && mysql -u root -e "SELECT 1;" >/dev/null 2>&1; then
    info "MySQL 服务已启动"
    return 0
  fi

  warn "MySQL 服务未能自动启动，尝试直接初始化..."
  if command -v mysqld >/dev/null 2>&1; then
    sudo mysqld_safe --skip-grant-tables &>/dev/null &
    sleep 3
    if mysql -u root -e "SELECT 1;" >/dev/null 2>&1; then
      info "MySQL 通过 mysqld_safe 启动成功"
      return 0
    fi
  fi

  warn "MySQL 可能已经运行或需要你手动启动。"
  echo "  手动启动方式："
  echo "    systemd : sudo systemctl start mysql  (Debian/Ubuntu) 或 sudo systemctl start mysqld (CentOS)"
  echo "    Homebrew: brew services start mysql"
  echo "    其他    : sudo service mysql start"
  return 0
}

setup_security() {
  warn "安全提醒："
  echo "  生产环境请务必运行以下命令进行安全加固："
  echo "    sudo mysql_secure_installation"
  echo "  这将引导你设置 root 密码、删除匿名用户、禁止 root 远程登录。"
  echo "  如果需要免密本地管理，也可以先跳过并在必要时再配置。"
}

create_demo_database() {
  step "创建示例数据库 shop 并导入测试数据..."

  # 等待 MySQL 完全就绪
  local retries=10
  while ! mysql -u root -e "SELECT 1;" >/dev/null 2>&1; do
    retries=$((retries - 1))
    if [ "$retries" -le 0 ]; then
      error "MySQL 仍未响应，无法创建数据库。"
      return 1
    fi
    info "等待 MySQL 就绪...（剩余 ${retries} 次尝试）"
    sleep 2
  done

  mysql -u root <<'SQLEOF'
CREATE DATABASE IF NOT EXISTS shop DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
USE shop;

DROP TABLE IF EXISTS orders;
DROP TABLE IF EXISTS products;
DROP TABLE IF EXISTS users;

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    email VARCHAR(100) NOT NULL,
    phone VARCHAR(20),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB;

CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(200) NOT NULL,
    price DECIMAL(10, 2) NOT NULL,
    stock INT DEFAULT 0,
    category VARCHAR(50),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB;

CREATE TABLE orders (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    product_id INT NOT NULL,
    quantity INT NOT NULL DEFAULT 1,
    order_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE RESTRICT
) ENGINE=InnoDB;

INSERT INTO users (username, email) VALUES
('alice', '[email protected]'),
('bob', '[email protected]'),
('charlie', '[email protected]');

INSERT INTO products (name, price, stock, category) VALUES
('机械键盘', 399.00, 50, '数码'),
('无线鼠标', 89.90, 200, '数码'),
('Python 入门教程', 49.00, 1000, '图书'),
('咖啡杯', 35.00, 300, '生活');

INSERT INTO orders (user_id, product_id, quantity) VALUES
(1, 1, 1),
(1, 3, 2),
(2, 2, 3);

CREATE INDEX idx_username ON users(username);
CREATE INDEX idx_category ON products(category);

SELECT 'Demo data inserted successfully!' AS status;
SQLEOF

  if [ $? -eq 0 ]; then
    info "示例数据库创建完成！"
    return 0
  else
    error "示例数据导入失败"
    return 1
  fi
}

verify_query() {
  step "验证安装——运行联合查询测试..."

  mysql -u root -D shop -e "
    SELECT u.username, p.name, o.quantity, o.order_time
    FROM users u
    JOIN orders o ON u.id = o.user_id
    JOIN products p ON o.product_id = p.id
    WHERE u.username = 'alice';
  " 2>/dev/null

  if [ $? -eq 0 ]; then
    info "查询验证通过！"
    return 0
  else
    error "查询验证失败"
    return 1
  fi
}

main() {
  echo "============================================"
  echo "  MySQL 索引与 SQL 优化实战 — 一键安装脚本"
  echo "  适用于 macOS / Linux / WSL"
  echo "============================================"
  echo ""

  local NET
  NET=$(detect_network)

  local OS_TYPE
  OS_TYPE=$(detect_os)

  if check_mysql_running; then
    info "MySQL 已在运行，跳过安装步骤"
  else
    case "$OS_TYPE" in
      debian)  install_on_debian "$NET" || exit 1 ;;
      redhat)  install_on_redhat ;;
      macos)   install_on_macos ;;
      alpine)  install_on_alpine ;;
      *)       warn "未知系统，尝试通用安装流程"; install_on_debian "$NET" || exit 1 ;;
    esac
  fi

  start_mysql
  setup_security
  create_demo_database
  verify_query

  echo ""
  echo "============================================"
  info "安装完成！"
  echo "  进入数据库：mysql -u root -p"
  echo "  选择示例库：USE shop;"
  echo "  查看用户表：SELECT * FROM users;"
  echo "  查看索引：  SHOW INDEX FROM users;"
  echo "  查看执行计划：EXPLAIN SELECT * FROM users WHERE username = 'alice';"
  echo ""
  echo "  后续请跑：sudo mysql_secure_installation 加固安全"
  echo "============================================"
}

main "$@"

# ============================================================
#  MySQL 索引与 SQL 优化实战 — 一键安装脚本（Windows PowerShell）
#  公开源码，欢迎审查 -- 不放心可先复制给 AI 判断
#  说明：MySQL 官方不支持 Windows 原生安装脚本分发，
#        本脚本调用 WSL 内的 Ubuntu 执行 Linux 版安装逻辑。
#        如果你没有 WSL，也可去 https://www.mysql.com/downloads/
#        下载安装包（Windows MSI 版）手动安装。
# ============================================================
$ErrorActionPreference = "Stop"

function Write-Info  { Write-Host "[INFO] $args" -ForegroundColor Green }
function Write-Warn  { Write-Host "[WARN] $args" -ForegroundColor Yellow }
function Write-Err   { Write-Host "[ERROR] $args" -ForegroundColor Red }
function Write-Step  { Write-Host "[STEP] $args" -ForegroundColor Cyan }

# 1. 安装策略：仅当前会话生效（Process 级别），关闭窗口即恢复，不动系统全局策略
Write-Step "准备执行环境..."

# 2. 检测 WSL
Write-Step "检查 WSL 环境..."
if (-not (Get-Command wsl -ErrorAction SilentlyContinue)) {
    Write-Err "未找到 wsl 命令。请先安装 WSL："
    Write-Host "  PowerShell（管理员）执行：wsl --install"
    Write-Host "  重启后安装 Ubuntu 发行版，再运行本脚本。"
    Write-Host ""
    Write-Host "如果不想用 WSL，也可以直接从官网下载 MySQL Installer："
    Write-Host "  https://dev.mysql.com/downloads/installer/"
    Write-Host "  （勾选 ghfast.top 代理加速：https://ghfast.top/https://dev.mysql.com/downloads/installer/ ）"
    exit 1
}

try {
    $wslDistros = wsl -l -q 2>$null
    if ($wslDistros -match "Ubuntu") {
        $wslDistro = "Ubuntu"
    } elseif ($wslDistros -match "Ubuntu-22.04") {
        $wslDistro = "Ubuntu-22.04"
    } elseif ($wslDistros -match "Ubuntu-20.04") {
        $wslDistro = "Ubuntu-20.04"
    } else {
        $firstDistro = ($wslDistros | Where-Object { $_.Trim() -and $_.Trim() -ne "CONTAINERS" -and $_.Trim() -ne "STATUS" -and $_.Trim() -ne "NAME" } | Select-Object -First 1).Trim()
        if ([string]::IsNullOrWhiteSpace($firstDistro)) {
            Write-Err "WSL 中未检测到可用的 Linux 发行版。请先运行：wsl --install"
            exit 1
        }
        $wslDistro = $firstDistro
    }
} catch {
    $wslDistro = "Ubuntu"
}
Write-Info "使用 WSL 发行版：$wslDistro"

# 3. 询问是否继续
Write-Host ""
Write-Host "本脚本将在 WSL（$wslDistro）中自动安装 MySQL 并导入示例数据。"
Write-Host "整个过程大约需要 3-10 分钟（取决于网速）。"
Write-Host "你也可以选择仅在本机安装 MySQL（通过官网安装包）而非在此脚本运行。"
$continue = Read-Host "继续在 WSL 中安装 MySQL？[Y/N]"
if ($continue -ne "Y" -and $continue -ne "y") {
    Write-Info "已选择跳过。需要时重新运行本脚本即可。"
    exit 0
}

# 4. 把 Linux 脚本注入 WSL 并执行
Write-Step "将安装脚本传入 WSL 并执行（首次执行会安装 MySQL，耗时较长）..."

$scriptPath = Join-Path $PSScriptRoot "install-mysql-guide.sh"
if (-not (Test-Path $scriptPath)) {
    Write-Warn "未找到同目录的 install-mysql-guide.sh，请将本 .ps1 与 install-mysql-guide.sh 放在同一目录后重跑。"
    Write-Host "（或者手动在 WSL 中下载脚本执行：）"
    Write-Host "  wsl -d $wslDistro -e bash -c ""curl -fsSL https://cleanresolver.com/scripts/install-mysql-guide.sh -o /tmp/install-mysql-guide.sh && bash /tmp/install-mysql-guide.sh"""
    exit 1
}

$remotePath = "/tmp/install-mysql-guide.sh"
$tempWindows = [System.IO.Path]::GetFullPath($env:TEMP)
$mntPath = "/mnt/c" + $tempWindows -replace '^C:', '' -replace '\\', '/'
$localScript = "$mntPath/install-mysql-guide-wsl.sh"

try {
    Copy-Item -Path $scriptPath -Destination $localScript -Force
    Write-Info "脚本已传入 WSL：$localScript"
} catch {
    Write-Err "传入 WSL 失败：$_"
    Write-Host "请手动在 WSL 中执行：bash <(curl -fsSL https://cleanresolver.com/scripts/install-mysql-guide.sh)"
    exit 1
}

Write-Host ""
Write-Host "正在 WSL 内执行安装（日志将直接输出）……"
Write-Host "============================================"
wsl -d $wslDistro -e bash $localScript
$code = $LASTEXITCODE
Write-Host "============================================"

if ($code -ne 0) {
    Write-Err "WSL 内安装失败（退出码 $code）。请对照上方报错处理，或手动在 WSL 中重试。"
    exit 1
}

Write-Host ""
Write-Host "============================================"
Write-Info "全部完成！接下来在 WSL 终端里："
Write-Host "    mysql -u root -p           # 进入数据库"
Write-Host "    USE shop;                   # 选择示例库"
Write-Host "    SELECT * FROM users;        # 查看用户表"
Write-Host "    EXPLAIN SELECT * FROM users WHERE username='alice';  # 查看执行计划"
Write-Host ""
Write-Host "Windows 浏览器可通过 localhost:3306 连接 MySQL（需配置端口转发）。"
Write-Host "============================================"