SELECT email FROM employees WHERE commission_pct  =  "null" AND salary BETWEEN 7000 AND 12000 AND department_id = 50
display the emails of the employees who have no commission percentage and salary within the range 7000 to 12000 and works in that department which number is 50.
CREATE TABLE IF NOT EXISTS `regions` (
  `REGION_ID` decimal(5,0) NOT NULL,
  `REGION_NAME` varchar(25) DEFAULT NULL,
  PRIMARY KEY (`REGION_ID`)
);
CREATE TABLE IF NOT EXISTS `countries` (
  `COUNTRY_ID` varchar(2) NOT NULL,
  `COUNTRY_NAME` varchar(40) DEFAULT NULL,
  `REGION_ID` decimal(10,0) DEFAULT NULL,
  PRIMARY KEY (`COUNTRY_ID`),
  FOREIGN KEY (`REGION_ID`) REFERENCES regions (`REGION_ID`)
);
CREATE TABLE IF NOT EXISTS `departments` (
  `DEPARTMENT_ID` decimal(4,0) NOT NULL DEFAULT '0',
  `DEPARTMENT_NAME` varchar(30) NOT NULL,
  `MANAGER_ID` decimal(6,0) DEFAULT NULL,
  `LOCATION_ID` decimal(4,0) DEFAULT NULL,
  PRIMARY KEY (`DEPARTMENT_ID`)
);
CREATE TABLE IF NOT EXISTS `jobs` (
  `JOB_ID` varchar(10) NOT NULL DEFAULT '',
  `JOB_TITLE` varchar(35) NOT NULL,
  `MIN_SALARY` decimal(6,0) DEFAULT NULL,
  `MAX_SALARY` decimal(6,0) DEFAULT NULL,
  PRIMARY KEY (`JOB_ID`)
);
CREATE TABLE IF NOT EXISTS `employees` (
  `EMPLOYEE_ID` decimal(6,0) NOT NULL DEFAULT '0',
  `FIRST_NAME` varchar(20) DEFAULT NULL,
  `LAST_NAME` varchar(25) NOT NULL,
  `EMAIL` varchar(25) NOT NULL,
  `PHONE_NUMBER` varchar(20) DEFAULT NULL,
  `HIRE_DATE` date NOT NULL,
  `JOB_ID` varchar(10) NOT NULL,
  `SALARY` decimal(8,2) DEFAULT NULL,
  `COMMISSION_PCT` decimal(2,2) DEFAULT NULL,
  `MANAGER_ID` decimal(6,0) DEFAULT NULL,
  `DEPARTMENT_ID` decimal(4,0) DEFAULT NULL,
  PRIMARY KEY (`EMPLOYEE_ID`),
  FOREIGN KEY (`DEPARTMENT_ID`) REFERENCES departments(`DEPARTMENT_ID`),
  FOREIGN KEY (`JOB_ID`) REFERENCES jobs(`JOB_ID`)
);
CREATE TABLE IF NOT EXISTS `job_history` (
  `EMPLOYEE_ID` decimal(6,0) NOT NULL,
  `START_DATE` date NOT NULL,
  `END_DATE` date NOT NULL,
  `JOB_ID` varchar(10) NOT NULL,
  `DEPARTMENT_ID` decimal(4,0) DEFAULT NULL,
  PRIMARY KEY (`EMPLOYEE_ID`,`START_DATE`),
  FOREIGN KEY (`EMPLOYEE_ID`) REFERENCES employees(`EMPLOYEE_ID`),
  FOREIGN KEY (`DEPARTMENT_ID`) REFERENCES departments(`DEPARTMENT_ID`),
  FOREIGN KEY (`JOB_ID`) REFERENCES jobs(`JOB_ID`)
);
CREATE TABLE IF NOT EXISTS `locations` (
  `LOCATION_ID` decimal(4,0) NOT NULL DEFAULT '0',
  `STREET_ADDRESS` varchar(40) DEFAULT NULL,
  `POSTAL_CODE` varchar(12) DEFAULT NULL,
  `CITY` varchar(30) NOT NULL,
  `STATE_PROVINCE` varchar(25) DEFAULT NULL,
  `COUNTRY_ID` varchar(2) DEFAULT NULL,
  PRIMARY KEY (`LOCATION_ID`),
  FOREIGN KEY (`COUNTRY_ID`) REFERENCES countries(`COUNTRY_ID`)
);
INSERT INTO `regions` (`REGION_ID`, `REGION_NAME`) VALUES
INSERT INTO `countries` (`COUNTRY_ID`, `COUNTRY_NAME`, `REGION_ID`) VALUES
INSERT INTO `departments` (`DEPARTMENT_ID`, `DEPARTMENT_NAME`, `MANAGER_ID`, `LOCATION_ID`) VALUES
INSERT INTO `jobs` (`JOB_ID`, `JOB_TITLE`, `MIN_SALARY`, `MAX_SALARY`) VALUES
INSERT INTO `employees` (`EMPLOYEE_ID`, `FIRST_NAME`, `LAST_NAME`, `EMAIL`, `PHONE_NUMBER`, `HIRE_DATE`, `JOB_ID`, `SALARY`, `COMMISSION_PCT`, `MANAGER_ID`, `DEPARTMENT_ID`) VALUES
INSERT INTO `job_history` (`EMPLOYEE_ID`, `START_DATE`, `END_DATE`, `JOB_ID`, `DEPARTMENT_ID`) VALUES
INSERT INTO `locations` (`LOCATION_ID`, `STREET_ADDRESS`, `POSTAL_CODE`, `CITY`, `STATE_PROVINCE`, `COUNTRY_ID`) VALUES