var db = new Client();
db.user = 'root';
db.password = 'root';
db.database = 'test';
db.connect();
db.query("SELECT SLEEP(1)",function(){console.log("First sleep");});
db.query("SELECT SLEEP(2)",function(){console.log("Second sleep");});
db.end();

Above script give below error;

itunali@itunali:~/nodejs$ ./bin/node my2.js
First sleep

/home/itunali/.node_libraries/mysql/query.js:42
field = this._fields[0];
^
TypeError: Cannot read property '0' of undefined
at Query._handlePacket (/home/itunali/.node_libraries/mysql/query.js:42:31)
at Client._handlePacket (/home/itunali/.node_libraries/mysql/client.js:194:14)
at Parser. (/home/itunali/.node_libraries/mysql/client.js:56:14)
at Parser.emit (events:26:26)
at Parser.write (/home/itunali/.node_libraries/mysql/parser.js:479:16)
at Stream. (/home/itunali/.node_libraries/mysql/client.js:51:16)
at Stream.emit (events:26:26)
at IOWatcher.callback (net:489:16)
at node.js:762:9