add mysql db

config.yml

@@ -2,4 +2,4 @@ app:
   port: 3000
 
 db:
-  type: mongodb # sqlite or mongodb
+  type: sqlite # sqlite or mongodb or mysql

db/index.js

@@ -8,6 +8,9 @@ switch(config.db.type){
   case 'mongodb':
     db = require('./mongodb')
     break;
+  case 'mysql':
+    db = require('./mysql')
+    break;
   case 'sqlite':
   default:
     db = require('./sqlite')

db/mysql.js

@@ -0,0 +1,70 @@
+'use strict'
+
+const mysql = require('mysql2')
+
+const mysqlURL = process.env.DB_URL || 'mysql://user:password@localhost:3306/database'
+
+let hosts = mysqlURL.split("://")[1].split("/")[0];
+let mysql_database = mysqlURL.split("://")[1].split("/")[1].split("?")[0];
+let mysql_user = hosts.split("@")[0].split(":")[0];
+let mysql_password = hosts.split("@")[0].split(":")[1];
+let mysql_host = hosts.split("@")[1].split(":")[0];
+let mysql_port = hosts.split("@")[1].split(":")[1];
+
+const db = mysql.createPool({
+    host: mysql_host,
+    user: mysql_user,
+    password: mysql_password,
+    database: mysql_database,
+    port: mysql_port
+})
+
+db.query(`CREATE TABLE IF NOT EXISTS tb_count (
+    id    INTEGER      PRIMARY KEY AUTO_INCREMENT
+                       NOT NULL
+                       UNIQUE,
+    name  VARCHAR (32) NOT NULL
+                       UNIQUE,
+    num   BIGINT       NOT NULL
+                       DEFAULT (0) 
+);`)
+
+function getNum(name) {
+  return new Promise((resolve, reject) => {
+    db.query('SELECT `name`, `num` from tb_count WHERE `name` = ?', name, (err, rows) => {
+      if (err) reject(err)
+
+      resolve(rows[0] || { name, num: 0 })
+    })
+  })
+}
+
+function getAll(name) {
+  return new Promise((resolve, reject) => {
+    db.query('SELECT * from tb_count', (err, rows) => {
+      if (err) reject(err)
+
+      resolve(rows)
+    })
+  })
+}
+
+function setNum(name, num) {
+  return new Promise((resolve, reject) => {
+    db.query(`INSERT INTO tb_count(\`name\`, \`num\`)
+              VALUES(?, ?)
+              ON DUPLICATE KEY UPDATE \`num\` = ?;`
+      , [name, num, num]
+      , (err, result) => {
+        if (err) reject(err)
+
+        resolve(result)
+      })
+ })
+}
+
+module.exports = {
+  getNum,
+  getAll,
+  setNum
+}

package.json

@@ -17,6 +17,7 @@
     "image-size": "^0.8.3",
     "mime-types": "^2.1.27",
     "mongoose": "^5.9.28",
+    "mysql2": "^3.3.5",
     "pug": "^3.0.0",
     "sqlite3": "^5.0.0"
   }