feat: 新增 nodejs 实验 8

Server/tests/test8/db.js

@@ -0,0 +1,24 @@
+const mysql = require("mysql2/promise")
+
+let pool;
+
+const connect = async () => {
+    if (!pool) {
+        pool = mysql.createPool({
+            host: "localhost",
+            user: "root",
+            password: "123456",
+            database: "express_db"
+        })
+    }
+    console.log("database is connect");
+    return pool;
+}
+
+module.exports = {
+    connect,
+    query: async (sql, values) => {
+        const pool = await connect();
+        return pool.query(sql, values);
+    }
+}