await

tools/app/promise-learn/build/index.js

@@ -1,27 +1,47 @@
 "use strict";
-const mariadb = require('mariadb');
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+const mariadb_1 = __importDefault(require("mariadb"));
 let conn;
-mariadb.createConnection({
+class DbHandle {
-    host: 'database',
+    constructor() { }
-    user: 'heroes',
+    async connect() {
-    password: 'test123',
+        this._conn = await mariadb_1.default.createConnection({
-    database: 'heroes'
+            host: '172.16.10.18',
-})
+            user: 'heroes',
-    .then(conn => {
+            password: 'test123',
-    conn.query("SELECT * FROM hero")
+            database: 'heroes'
-        .then((rows) => {
+        });
-        console.log(rows);
+    }
-        return rows;
+    get(stmt) {
+        var _a, _b;
+        return (_b = (_a = this._conn) === null || _a === void 0 ? void 0 : _a.query(stmt)) !== null && _b !== void 0 ? _b : Promise.reject(new Error('Connection not ready 1'));
+    }
+    close() {
+        var _a, _b;
+        return (_b = (_a = this._conn) === null || _a === void 0 ? void 0 : _a.end()) !== null && _b !== void 0 ? _b : Promise.reject(new Error('Connection not ready 2'));
+    }
+}
+const dbHandle = new DbHandle();
+/*
+dbHandle.connect()
+    .then(() => dbHandle.get("SELECT * FROM hero"))
+    .then((result) => {
+        console.log(result)
+        return dbHandle.close()
     })
-        .then((res) => {
+    .catch((err) => {
-        console.log(res);
+        console.log(err)
-        conn.end();
+    }
-    })
+    
-        .catch(err => {
+*/
-        console.log(err);
+dbHandle.get("SELECT * FROM hero")
-        conn.end();
+    .then((result) => {
-    });
+    console.log(result);
+    return dbHandle.close();
 })
-    .catch(err => {
+    .catch((err) => {
-    console.log('not connected');
+    console.log(err.message);
 });

tools/app/promise-learn/package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "build": "rm -rf ./build && tsc",
+    "build": "tsc",
     "start": "npm run build && node build/index.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },

tools/app/promise-learn/src/index.ts

@@ -1,31 +1,63 @@
-const mariadb = require('mariadb')
+import mariadb from 'mariadb'
 
 let conn : mariadb.Connection
 
-mariadb.createConnection({
+
-        host: 'database',
+class DbHandle {
-        user: 'heroes',
+    private _conn? : mariadb.Connection
-        password: 'test123',
+
-        database: 'heroes'
+    public constructor() {}
-    })
+
-    .then(conn => {
+    public async connect() : Promise<void> {
-        conn.query("SELECT * FROM hero")
+        this._conn = await mariadb.createConnection({
-            .then((rows) => {
+            host: '172.16.10.18',
-                console.log(rows)
+            user: 'heroes',
-                return rows
+            password: 'test123',
-            })
+            database: 'heroes'
-            .then((res) => {
+        })
-                console.log(res)
+    }
-                conn.end()
+
-            })
+    public get(stmt : string) : Promise<any> {
-            .catch(err => {
+        return this._conn?.query(stmt) ?? Promise.reject(new Error('Connection not ready 1'))
-                console.log(err)
+    }
-                conn.end()
+
-            })
+    public close() : Promise<void> {
-    })
+        return this._conn?.end() ?? Promise.reject(new Error('Connection not ready 2'))
-    .catch(err => {
+    }
-        console.log('not connected')
+}
-    })
 
 
 
+/*
+const dbHandle = new DbHandle()
+dbHandle.connect()
+    .then(() => dbHandle.get("SELECT * FROM hero"))
+    .then((result) => { 
+        console.log(result)
+        return dbHandle.close() 
+    })
+    .catch((err) => {
+        console.log(err)
+    })
+*/
+
+async function exec() : Promise<void> {
+    const dbHandle = new DbHandle()
+    await dbHandle.connect()
+    const result = await dbHandle.get("SELECT * FROM hero")
+    console.log(result)
+    await dbHandle.close()
+}
+
+exec().catch((err) => console.log(err.message))
+
+/*
+dbHandle.get("SELECT * FROM hero")
+    .then((result) => { 
+        console.log(result)
+        return dbHandle.close() 
+    })
+    .catch((err) => {
+        console.log(err.message)
+    })
+*/