crud helpers

Author: Pankaj Patel

.env.example

@@ -0,0 +1,4 @@
+DB_HOST=localhost
+DB_USER=root
+DB_PASS=
+DB_DATABASE=twitter_clone

.gitignore

@@ -61,3 +61,4 @@ typings/
 .next
 
 *.spf
+.env

README.md

@@ -17,3 +17,71 @@ You cna run this collection in Postman with following button:
 
 
 Or Download and import in Postman from here: <a href="./Twitter Clone.postman_collection.json" download>Download</a>
+
+-----
+
+```sql
+CREATE DATABASE twitter_clone;
+
+use twitter_clone;
+
+CREATE TABLE users(
+  id int NOT NULL AUTO_INCREMENT,
+  username varchar(15) NOT NULL,
+  password varchar(32) NOT NULL,
+  followers int DEFAULT 0,
+  following int DEFAULT 0,
+  tweets int DEFAULT 0,
+  PRIMARY KEY (id)
+);
+
+CREATE TABLE following(
+  id int NOT NULL AUTO_INCREMENT,
+  user1_id int REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
+  user2_id int REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
+  PRIMARY KEY (id)
+);
+
+CREATE TABLE tweets(
+  id int NOT NULL AUTO_INCREMENT,
+  username varchar(15) NOT NULL,
+  user_id int REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
+  tweet varchar(140) NOT NULL,
+  timestamp TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (id)
+);
+
+INSERT INTO USERS(username, password) VALUE('pankaj', MD5('pankaj'));
+
+INSERT INTO USERS(username, password) VALUE('tim', MD5('tim'));
+
+INSERT INTO USERS(username, password) VALUE('jim', MD5('jim'));
+
+INSERT INTO TWEETS(username, user_id, tweet) VALUE('pankaj', 1, 'Hello World Again!');
+
+INSERT INTO FOLLOWING(user1_id, user2_id) VALUE(1, 2);
+INSERT INTO FOLLOWING(user1_id, user2_id) VALUE(1, 3);
+INSERT INTO FOLLOWING(user1_id, user2_id) VALUE(3, 1);
+
+SELECT * FROM tweets;
+
+# Followers
+
+SELECT
+USER_INFO.*, username as user1_username
+FROM (SELECT 
+user1_id, user2_id, username as user2_username
+FROM FOLLOWING LEFT JOIN USERS ON user2_id = users.id
+WHERE user1_id = 1) as USER_INFO
+LEFT JOIN USERS ON user1_id = users.id ;
+
+# Following
+
+SELECT
+USER_INFO.*, username as user1_username
+FROM (SELECT 
+user1_id, user2_id, username as user2_username
+FROM FOLLOWING LEFT JOIN USERS ON user2_id = users.id
+WHERE user2_id = 1) as USER_INFO
+LEFT JOIN USERS ON user1_id = users.id ;
+```

Twitter Clone.postman_collection.json

@@ -2,7 +2,7 @@
 	"info": {
 		"_postman_id": "78149020-40a3-4657-80a9-7683bdae2c78",
 		"name": "Twitter Clone",
-		"description": "This collection is created to help understand the Rest API creation on Node.js with Express and MySQL\n\nThe original article can be found here: https://time2hack.com/2019/09/creating-rest-api-in-node-js-with-express-and-mysql",
+		"description": "This collection is created to help understand the Rest API creation on Node.js with Express and MySQL\n\nThe original article can be found here: https://time2hack.com/2019/09/creating-rest-api-in-node-js-with-express-and-mysql/",
 		"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json"
 	},
 	"item": [
@@ -223,12 +223,12 @@
 					"urlencoded": [
 						{
 							"key": "username",
-							"value": "jim",
+							"value": "r_{{$randomUserName}}",
 							"type": "text"
 						},
 						{
 							"key": "password",
-							"value": "jim",
+							"value": "random-password",
 							"type": "text"
 						}
 					]
@@ -241,18 +241,6 @@
 					"path": [
 						"auth",
 						"register"
-					],
-					"query": [
-						{
-							"key": "username",
-							"value": "",
-							"disabled": true
-						},
-						{
-							"key": "password",
-							"value": "",
-							"disabled": true
-						}
 					]
 				},
 				"description": "# Register New User\n---\n\n## Params\n\n`username`: `String`\n`password`: `String`\n\nReturns the new User's ID and Set's to Environment"
@@ -319,12 +307,46 @@
 			"response": []
 		}
 	],
+	"event": [
+		{
+			"listen": "prerequest",
+			"script": {
+				"id": "9f38fe7c-852d-47ea-94c0-a30a02fe80f1",
+				"type": "text/javascript",
+				"exec": [
+					""
+				]
+			}
+		},
+		{
+			"listen": "test",
+			"script": {
+				"id": "fbd831b3-89ea-4af7-9e1c-b34bd57dba5e",
+				"type": "text/javascript",
+				"exec": [
+					""
+				]
+			}
+		}
+	],
 	"variable": [
 		{
-			"id": "363978da-cd5b-42e5-97e7-a8f9aab3fbd0",
+			"id": "163f6187-2a19-4028-b6d8-ec8709bc560b",
+			"key": "url",
+			"value": "http://localhost:3000",
+			"type": "string"
+		},
+		{
+			"id": "974aa83a-3a22-483b-8363-e514a2742d5e",
 			"key": "user",
 			"value": "1",
 			"type": "string"
+		},
+		{
+			"id": "ddcb6d1f-4270-4364-bdcf-5e75ec9afeb4",
+			"key": "randomPassword",
+			"value": "random-password",
+			"type": "string"
 		}
 	],
 	"protocolProfileBehavior": {}

app-middlewares/auth.js

@@ -5,19 +5,23 @@ const query = require('../helpers/query');
 const router = express.Router();
 const dbConfig = require('../dbConfig');
 
+const create = require('../crud/create');
+
 router.post('/register', async (req, res) => {
   const { username, password } = req.body;
   const conn = await connection(dbConfig).catch(e => {});
-  const user = await query(
+  const result = await create(
     conn,
-    `INSERT INTO USERS(username, password) VALUE(?, MD5(?));`,
-    [username, password]
+    'USERS',
+    ['username', 'password'],
+    [username, { toString: () => `MD5('${password}')`}]
   );
-  if (user.insertId) {
-    res.send(await query(conn, `SELECT id, username FROM USERS WHERE ID=?`, [user.insertId]))
-    return;
-  }
-  res.send({ id: null, username: null });
+
+  const [user = {}] = result;
+  res.send({
+    id: user.id || null,
+    username: user.username || null,
+  });
 });
 
 router.post('/login', async (req, res) => {

crud/create.js

@@ -0,0 +1,20 @@
+const query = require('../helpers/query');
+const valuesForQuery = require('../helpers/values-for-insert');
+
+/**
+ * @param  {} conn MySQL Connection reference
+ * @param  {String} table Table to insert the values
+ * @param  {[String]} columns Array of column names
+ * @param  {[String]} values Array of values for those column names, can be multidientional
+ */
+module.exports = async (conn, table, columns, values) => {
+  const VALUES = valuesForQuery(values)
+  try {
+    const user = await query(conn, `INSERT INTO ${table}(${columns.join(', ')}) VALUES ${VALUES};`);
+    if (user.insertId) {
+      console.log(user.insertId);
+      return await query(conn, `SELECT * FROM ${table} WHERE ID=?`, [user.insertId]);
+    }
+    return user;
+  } catch(e) { console.log(e)}
+}

dbConfig.js

@@ -1,3 +1,7 @@
+const dotenv = require("dotenv")
+ 
+dotenv.config();
+
 // Get the Host from Environment or use default
 const host = process.env.DB_HOST || 'localhost';
 

helpers/query.js

@@ -8,4 +8,4 @@ module.exports = async (conn, q, params) => new Promise(
     resolve(result);
   }
   conn.query(q, params, handler);
-});
+}).catch(console.log);

helpers/values-for-insert.js

@@ -0,0 +1,38 @@
+/**
+ * @param  {[String]} values Array of values for those column names
+ */
+const valueForQuery = (_values) => {
+  const values = _values.map(item => {
+    let val;
+    switch (typeof item) {
+      case 'number':
+        return item;
+      case 'string':
+        val = item;
+        break;
+      default:
+        return item.toString();
+    }
+    return `'${val}'`;
+  })
+  return `(${values.join(', ')})`;
+};
+
+/**
+ * @param  {[String]} values Array of values for those column names, can be multidientional
+ */
+const valuesForQuery = (values) => {
+  const value = values[0];
+  let VALUES = '';
+  if (value instanceof Array) {
+    VALUES = values.map(valueForQuery).join(', ')
+  } else {
+    VALUES = valueForQuery(values);
+  }
+  return VALUES;
+}
+
+module.exports = {
+  valueForQuery,
+  valuesForQuery,
+}