Added guild member remove event.

events/memberremove.js

+module.exports = {
+    guildmemberremove: (client, connection) => {
+        client.on('guildMemberRemove', async (member) => {
+            let channel_db;
+            let message_db;
+            await connection.query(`SELECT message FROM leave_message WHERE guild ='${member.guild.id}'`, function (err, result) {
+                if (err){
+                    throw err;
+                };
+                if (result.length < 1) {
+                    message_db = `<@${member.id}> left the server.`;
+                } else {
+                    message_db = result[0].message;
+                };
+            });
+
+            await connection.query(`SELECT channel FROM leave_channel WHERE guild ='${member.guild.id}'`, function (err, result) {
+                if (err){
+                    throw err;
+                };
+                if (result.length < 1) {
+                    return;
+                } else {
+                    channel_db = result[0].channel;
+                    const channel = member.guild.channels.cache.get(channel_db);
+                    if (!channel) {
+                        return;
+                    };
+                    channel.send(message_db ? message_db.replace('{mention}', `${member}`).replace('{username}', `${member.user.username}`) : ``).catch(e => {
+                        return;
+                    });        
+                }
+            });
+        });
+    }
+};

main.js

@@ -5,6 +5,7 @@ const dbconfig = require('./dbconfig.json');
 const ready = require('./events/ready');
 const message = require('./events/message');
 const memberadd = require('./events/memberadd');
+const memberremove = require('./events/memberremove');
 const fs = require('fs');
 const mysql = require('mysql');
 
@@ -27,6 +28,7 @@ client.aliases = new Discord.Collection();
 ready.ready(client);
 message.message(client, config, Discord, connection);
 memberadd.guildmemberadd(client, connection);
+memberremove.guildmemberremove(client, connection);
 
 fs.readdir("./commands/", (err, files) => {