Connect in db module

Author: Cyclonecode

scripts/db.js

@@ -1,5 +1,6 @@
 require('dotenv').config();
 const mysql = require('mysql');
+const logger = require('./logger');
 // parse any arguments
 const argv = require('minimist')(process.argv.slice(2));
 
@@ -17,6 +18,13 @@ const connection = mysql.createConnection({
   port: MYSQL_PORT,
 });
 
+connection.connect((err) => {
+  if (err) {
+    logger.error('Failed to connect');
+    throw err;
+  }
+});
+
 module.exports = {
   argv,
   connection,

scripts/delete.js

@@ -3,18 +3,12 @@ const logger = require('./logger');
 const connection = require('./db').connection;
 const argv = require('./db').argv;
 
-connection.connect((err) => {
+const sql = 'DELETE FROM post' + (argv.id ? ' WHERE id = ?' : '');
+const data = argv.id ? [argv.id] : [];
+connection.query(sql, data, (err, result) => {
   if (err) {
-    logger.error('Failed to connect');
     throw err;
   }
-  const sql = 'DELETE FROM post' + (argv.id ? ' WHERE id = ?' : '');
-  const data = argv.id ? [argv.id] : [];
-  connection.query(sql, data, (err, result) => {
-    if (err) {
-      throw err;
-    }
-    logger.info('Removed ' + result.affectedRows + ' record(s)');
-  });
-  connection.end();
+  logger.info('Removed ' + result.affectedRows + ' record(s)');
 });
+connection.end();

scripts/insert.js

@@ -7,18 +7,12 @@ const title = argv.title || '';
 const content = argv.content || '';
 const image = argv.image || '';
 
-connection.connect((err) => {
+const sql = 'INSERT INTO post VALUES(NULL, ?, ?, ?)';
+const data = [title, content, image];
+connection.query(sql, data, (err, result) => {
   if (err) {
-    logger.error('Failed to connect');
     throw err;
   }
-  const sql = 'INSERT INTO post VALUES(NULL, ?, ?, ?)';
-  const data = [title, content, image];
-  connection.query(sql, data, (err, result) => {
-    if (err) {
-      throw err;
-    }
-    logger.info('Inserted ' + result.affectedRows + ' record(s)');
-  });
-  connection.end();
+  logger.info('Inserted ' + result.affectedRows + ' record(s)');
 });
+connection.end();

scripts/select.js

@@ -1,26 +1,20 @@
 #!/usr/bin/env node
 const connection = require('./db').connection;
-const argv = require('./db').argv;
 const logger = require('./logger');
+const argv = require('./db').argv;
 
-connection.connect((err) => {
+let sql = 'SELECT * FROM post';
+const data = [];
+if (argv.id) {
+  sql += ' WHERE id = ?';
+  data.push(argv.id);
+}
+connection.query(sql, data, (err, result) => {
   if (err) {
-    logger.error('Failed to connect');
     throw err;
   }
-  let sql = 'SELECT * FROM post';
-  const data = [];
-  if (argv.id) {
-    sql += ' WHERE id = ?';
-    data.push(argv.id);
-  }
-  connection.query(sql, data, (err, result) => {
-    if (err) {
-      throw err;
-    }
-    result.forEach(it => {
-      logger.info('', it);
-    });
+  result.forEach(it => {
+    logger.info('', it);
   });
-  connection.end();
 });
+connection.end();

scripts/update.js

@@ -10,33 +10,27 @@ if (!argv.title && !argv.content && !argv.image) {
   throw new Error('You need to specify some value to change.');
 }
 
-connection.connect((err) => {
+let sql = 'UPDATE post SET ';
+const data = [];
+if (argv.title) {
+  sql += 'title = ?,';
+  data.push(argv.title);
+}
+if (argv.content) {
+  sql += 'content = ?,';
+  data.push(argv.content);
+}
+if (argv.image) {
+  sql += 'image = ?,';
+  data.push(argv.image);
+}
+sql = sql.slice(0, -1);
+sql += ' WHERE id = ?';
+data.push(argv.id);
+connection.query(sql, data, (err, result) => {
   if (err) {
-    logger.error('Failed to connect');
     throw err;
   }
-  let sql = 'UPDATE post SET ';
-  const data = [];
-  if (argv.title) {
-    sql += 'title = ?,';
-    data.push(argv.title);
-  }
-  if (argv.content) {
-    sql += 'content = ?,';
-    data.push(argv.content);
-  }
-  if (argv.image) {
-    sql += 'image = ?,';
-    data.push(argv.image);
-  }
-  sql = sql.slice(0, -1);
-  sql += ' WHERE id = ?';
-  data.push(argv.id);
-  connection.query(sql, data, (err, result) => {
-    if (err) {
-      throw err;
-    }
-    logger.info('Updated ' + result.affectedRows + ' record(s)');
-  });
-  connection.end();
+  logger.info('Updated ' + result.affectedRows + ' record(s)');
 });
+connection.end();