Php-dbms-project

A simple website that shows farmers details and a portal for them to buy and sell produce.
put all files in htdocs folder of xampp
in phpmyadmin, create the following tables:
CREATE TABLE advisor ( aid varchar(5) NOT NULL, name varchar(50) DEFAULT NULL, address varchar(150) DEFAULT NULL, salary decimal(10,5) DEFAULT NULL, number varchar(10) DEFAULT NULL, PRIMARY KEY (aid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE equipment ( eid varchar(5) NOT NULL, name varchar(50) DEFAULT NULL, PRIMARY KEY (eid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE crop ( cid varchar(5) NOT NULL, cname varchar(50) DEFAULT NULL, ctype varchar(50) DEFAULT NULL, water_req decimal(10,5) DEFAULT NULL, fid varchar(5) DEFAULT NULL, sid varchar(5) DEFAULT NULL, PRIMARY KEY (cid), KEY sid (sid), KEY fid (fid), CONSTRAINT crop_ibfk_1 FOREIGN KEY (sid) REFERENCES seed (sid), CONSTRAINT crop_ibfk_2 FOREIGN KEY (fid) REFERENCES fertilizer (fid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE farmer ( fid varchar(5) NOT NULL, dob date DEFAULT NULL, name varchar(50) DEFAULT NULL, gender char(1) DEFAULT NULL, lid varchar(5) DEFAULT NULL, aid varchar(5) DEFAULT NULL, phone varchar(15) NOT NULL, email varchar(100) NOT NULL, PRIMARY KEY (fid), KEY lid (lid), KEY aid (aid), CONSTRAINT farmer_ibfk_1 FOREIGN KEY (lid) REFERENCES location (lid), CONSTRAINT farmer_ibfk_2 FOREIGN KEY (aid) REFERENCES advisor (aid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE users ( id int(11) NOT NULL AUTO_INCREMENT, first_name varchar(100) COLLATE utf8_unicode_ci NOT NULL, last_name varchar(100) COLLATE utf8_unicode_ci NOT NULL, email varchar(100) COLLATE utf8_unicode_ci NOT NULL, password varchar(255) COLLATE utf8_unicode_ci NOT NULL, phone varchar(15) COLLATE utf8_unicode_ci NOT NULL, created datetime NOT NULL, modified datetime NOT NULL, status enum('1','0') COLLATE utf8_unicode_ci NOT NULL DEFAULT '1', gender char(1) COLLATE utf8_unicode_ci NOT NULL, dob date NOT NULL, area varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=23 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci CREATE TABLE fertilizer ( fid varchar(5) NOT NULL, name varchar(50) DEFAULT NULL, type varchar(20) DEFAULT NULL, npk varchar(20) DEFAULT NULL, PRIMARY KEY (fid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE sell_seed ( sid varchar(5) NOT NULL, seedid varchar(5) NOT NULL, cost decimal(20,5) DEFAULT NULL, PRIMARY KEY (sid,seedid), KEY seedid (seedid), CONSTRAINT sell_seed_ibfk_1 FOREIGN KEY (sid) REFERENCES supplier (sid), CONSTRAINT sell_seed_ibfk_2 FOREIGN KEY (seedid) REFERENCES seed (sid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE seed ( sid varchar(5) NOT NULL, name varchar(50) DEFAULT NULL, shelf_life int(11) DEFAULT NULL, str_condn varchar(50) DEFAULT NULL, soil varchar(50) DEFAULT NULL, PRIMARY KEY (sid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE supplier ( sid varchar(5) NOT NULL, name varchar(50) DEFAULT NULL, address varchar(150) DEFAULT NULL, number varchar(10) DEFAULT NULL, PRIMARY KEY (sid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE sell_fertilizer ( sid varchar(5) NOT NULL, fid varchar(5) NOT NULL, cost decimal(20,5) DEFAULT NULL, PRIMARY KEY (sid,fid), KEY fid (fid), CONSTRAINT sell_fertilizer_ibfk_1 FOREIGN KEY (sid) REFERENCES supplier (sid), CONSTRAINT sell_fertilizer_ibfk_2 FOREIGN KEY (fid) REFERENCES fertilizer (fid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE sell_equipment ( sid varchar(5) NOT NULL, eid varchar(5) NOT NULL, cost decimal(20,5) DEFAULT NULL, PRIMARY KEY (sid,eid), KEY eid (eid), CONSTRAINT sell_equipment_ibfk_1 FOREIGN KEY (sid) REFERENCES supplier (sid), CONSTRAINT sell_equipment_ibfk_2 FOREIGN KEY (eid) REFERENCES equipment (eid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 CREATE TABLE location ( lid varchar(5) NOT NULL, lname varchar(50) DEFAULT NULL, weather varchar(50) DEFAULT NULL, soil_type varchar(50) DEFAULT NULL, pests varchar(200) DEFAULT NULL, pesticides varchar(100) DEFAULT NULL, PRIMARY KEY (lid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4