Query across multiple databases in MySQL

database-schema.sql

DROP TABLE IF EXISTS `departments`;
CREATE TABLE `departments` (
  `dept_no` char(4) NOT NULL,
  `dept_name` varchar(40) NOT NULL,
  PRIMARY KEY (`dept_no`),
  UNIQUE KEY `dept_name` (`dept_name`),
  KEY `idx_deptno` (`dept_no`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

DROP TABLE IF EXISTS `dept_emp`;
CREATE TABLE `dept_emp` (
  `emp_no` int(11) NOT NULL,
  `dept_no` char(4) NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date NOT NULL,
  PRIMARY KEY (`emp_no`,`dept_no`),
  KEY `emp_no` (`emp_no`),
  KEY `dept_no` (`dept_no`),
  CONSTRAINT `dept_emp_ibfk_1` FOREIGN KEY (`emp_no`) REFERENCES `employees` (`emp_no`) ON DELETE CASCADE,
  CONSTRAINT `dept_emp_ibfk_2` FOREIGN KEY (`dept_no`) REFERENCES `departments` (`dept_no`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

DROP TABLE IF EXISTS `employees`;
CREATE TABLE `employees` (
  `emp_no` int(11) NOT NULL,
  `birth_date` date NOT NULL,
  `first_name` varchar(14) NOT NULL,
  `last_name` varchar(16) NOT NULL,
  `gender` enum('M','F') NOT NULL,
  `hire_date` date NOT NULL,
  PRIMARY KEY (`emp_no`),
  KEY `idx_lastname_firstname` (`last_name`,`first_name`) USING BTREE,
  KEY `idx_hiredate` (`hire_date`) USING BTREE,
  KEY `idx_birthdate` (`birth_date`) USING BTREE,
  KEY `idx_empno` (`emp_no`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

multiple-database-query.sql

select emp.emp_no, emp.first_name, emp.last_name, dept.dept_name
from employees.employees emp, homestead.departments dept, homestead.dept_emp de
where (de.dept_no = dept.dept_no and de.emp_no = emp.emp_no)
limit 1, 20