/**
* MCP Server实现
* 基于@modelcontextprotocol/sdk实现MySQL工具服务
*/
const { Server } = require('@modelcontextprotocol/sdk/server/index.js');
const { StdioServerTransport } = require('@modelcontextprotocol/sdk/server/stdio.js');
const {
ListToolsRequestSchema,
CallToolRequestSchema,
} = require('@modelcontextprotocol/sdk/types.js');
const DatabaseManager = require('./database');
const SQLValidator = require('./validators');
const config = require('./config');
class MCPMySQLServer {
constructor() {
this.server = new Server({
name: config.mcp.name,
version: config.mcp.version,
}, {
capabilities: {
tools: {},
},
});
this.dbManager = new DatabaseManager();
this.validator = new SQLValidator();
this.setupHandlers();
}
/**
* 设置MCP服务器处理器
*/
setupHandlers() {
// 列出可用工具
this.server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: [
{
name: "execute_sql",
description: "执行SQL查询语句，支持SELECT、INSERT、UPDATE、DELETE操作",
inputSchema: {
type: "object",
properties: {
sql: {
type: "string",
description: "要执行的SQL语句"
},
params: {
type: "array",
description: "SQL查询参数（可选）",
items: {
type: ["string", "number", "boolean", "null"]
}
}
},
required: ["sql"]
}
},
{
name: "get_tables_info",
description: "获取数据库表结构信息",
inputSchema: {
type: "object",
properties: {}
}
},
{
name: "get_connection_status",
description: "获取数据库连接状态",
inputSchema: {
type: "object",
properties: {}
}
}
]
};
});
// 执行工具调用
this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
const { name, arguments: args } = request.params;
try {
switch (name) {
case "execute_sql":
return await this.handleExecuteSQL(args);
case "get_tables_info":
return await this.handleGetTablesInfo();
case "get_connection_status":
return await this.handleGetConnectionStatus();
default:
throw new Error(`未知的工具: ${name}`);
}
} catch (error) {
return {
content: [
{
type: "text",
text: `错误: ${error.message}`
}
],
isError: true
};
}
});
}
/**
* 处理SQL执行请求
* @param {Object} args - 请求参数
* @returns {Object} 执行结果
*/
async handleExecuteSQL(args) {
const { sql, params = [] } = args;
// 验证SQL语句
const sqlValidation = this.validator.validateSQL(sql);
if (!sqlValidation.isValid) {
return {
content: [
{
type: "text",
text: `SQL验证失败: ${sqlValidation.error}`
}
],
isError: true
};
}
// 验证参数
const paramsValidation = this.validator.validateParams(params);
if (!paramsValidation.isValid) {
return {
content: [
{
type: "text",
text: `参数验证失败: ${paramsValidation.error}`
}
],
isError: true
};
}
// 执行SQL
const result = await this.dbManager.executeQuery(sql, params);
if (result.success) {
let responseText = `✓ SQL执行成功\n`;
responseText += `操作类型: ${result.operation}\n`;
responseText += `执行时间: ${result.executionTime}ms\n`;
responseText += `影响行数: ${result.rowCount}\n`;
if (result.insertId) {
responseText += `插入ID: ${result.insertId}\n`;
}
if (result.operation === 'SELECT' && result.data.length > 0) {
responseText += `\n查询结果:\n`;
responseText += JSON.stringify(result.data, null, 2);
}
return {
content: [
{
type: "text",
text: responseText
}
]
};
} else {
return {
content: [
{
type: "text",
text: `✗ SQL执行失败: ${result.error}`
}
],
isError: true
};
}
}
/**
* 处理获取表信息请求
* @returns {Object} 表信息
*/
async handleGetTablesInfo() {
const result = await this.dbManager.getTablesInfo();
if (result.success) {
let responseText = `数据库表信息:\n\n`;
for (const table of result.data) {
responseText += `表名: ${table.name}\n`;
responseText += `字段信息:\n`;
for (const column of table.columns) {
responseText += ` - ${column.Field} (${column.Type}) ${column.Null === 'NO' ? 'NOT NULL' : 'NULL'} ${column.Key ? column.Key : ''}\n`;
}
responseText += `\n`;
}
return {
content: [
{
type: "text",
text: responseText
}
]
};
} else {
return {
content: [
{
type: "text",
text: `获取表信息失败: ${result.error}`
}
],
isError: true
};
}
}
/**
* 处理获取连接状态请求
* @returns {Object} 连接状态
*/
async handleGetConnectionStatus() {
const isActive = this.dbManager.isConnectionActive();
return {
content: [
{
type: "text",
text: `数据库连接状态: ${isActive ? '已连接' : '未连接'}`
}
]
};
}
/**
* 启动MCP服务器
*/
async start() {
try {
// 初始化数据库连接
await this.dbManager.initialize();
// 启动MCP服务器
const transport = new StdioServerTransport();
await this.server.connect(transport);
console.log(`✓ MCP MySQL Server 启动成功`);
console.log(`服务器名称: ${config.mcp.name}`);
console.log(`服务器版本: ${config.mcp.version}`);
} catch (error) {
console.error('✗ MCP服务器启动失败:', error.message);
process.exit(1);
}
}
/**
* 停止服务器
*/
async stop() {
await this.dbManager.close();
console.log('✓ MCP服务器已停止');
}
}
module.exports = MCPMySQLServer;