Foreign Key Index Issue

-- MySQL Workbench Forward Engineering

SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';

-- -----------------------------------------------------
-- Schema azziedev_attendtudb
-- -----------------------------------------------------

-- -----------------------------------------------------
-- Schema azziedev_attendtudb
-- -----------------------------------------------------
CREATE SCHEMA IF NOT EXISTS `azziedev_attendtudb` DEFAULT CHARACTER SET utf8 ;
USE `azziedev_attendtudb` ;

-- -----------------------------------------------------
-- Table `azziedev_attendtudb`.`Branch`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `azziedev_attendtudb`.`Branch` (
  `branchNo` VARCHAR(5) NOT NULL,
  `street` VARCHAR(45) NOT NULL,
  `city` VARCHAR(45) NOT NULL,
  `postcode` VARCHAR(45) NOT NULL,
  PRIMARY KEY (`branchNo`))
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `azziedev_attendtudb`.`Staff`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `azziedev_attendtudb`.`Staff` (
  `staffNo` VARCHAR(20) NOT NULL,
  `fName` VARCHAR(45) NOT NULL,
  `lName` VARCHAR(45) NOT NULL,
  `position` VARCHAR(45) NOT NULL,
  `sex` VARCHAR(1) NOT NULL,
  `DOB` DATE NOT NULL,
  `salary` INT NOT NULL,
  `branchNo` VARCHAR(5) NOT NULL,
  PRIMARY KEY (`staffNo`),
  CONSTRAINT `branchNo`
    FOREIGN KEY (`branchNo`)
    REFERENCES `azziedev_attendtudb`.`Branch` (`branchNo`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `azziedev_attendtudb`.`users`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `azziedev_attendtudb`.`users` (
  `netid` VARCHAR(20) NOT NULL,
  `firstname` VARCHAR(45) NOT NULL,
  `lastname` VARCHAR(45) NOT NULL,
  PRIMARY KEY (`netid`))
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `azziedev_attendtudb`.`sessions`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `azziedev_attendtudb`.`sessions` (
  `idsessions` INT NOT NULL,
  `creatorid` VARCHAR(20) NOT NULL,
  `courseid` INT NULL,
  PRIMARY KEY (`idsessions`),
  INDEX `netid_idx` (`creatorid` ASC) VISIBLE,
  CONSTRAINT `netid`
    FOREIGN KEY (`creatorid`)
    REFERENCES `azziedev_attendtudb`.`users` (`netid`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;


SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;