Question

I was create tables with the syntax in phpmyadmin:

DROP TABLE IF EXISTS users;
DROP TABLE IF EXISTS info;

CREATE TABLE users (
  user_id int unsigned NOT NULL auto_increment,
  email varchar(100) NOT NULL default '',
  pwd varchar(32) NOT NULL default '',
  isAdmin int(1) unsigned NOT NULL,
  PRIMARY KEY  (user_id)
) TYPE=INNODB;

CREATE TABLE info (
  info_id int unsigned NOT NULL auto_increment,
  first_name varchar(100) NOT NULL default '',
  last_name varchar(100) NOT NULL default '',
  address varchar(300) NOT NULL default '',
  zipcode varchar(100) NOT NULL default '',
  personal_phone varchar(100) NOT NULL default '',
  mobilephone varchar(100) NOT NULL default '',
  faxe varchar(100) NOT NULL default '',
  email2 varchar(100) NOT NULL default '',
  country varchar(100) NOT NULL default '',
  sex varchar(1) NOT NULL default '',
  birth varchar(1) NOT NULL default '',

  email varchar(100) NOT NULL default '',
  PRIMARY KEY  (info_id),
  FOREIGN KEY (email) REFERENCES users(email) ON UPDATE CASCADE ON DELETE CASCADE
) TYPE=INNODB;

But shows the error:

“#1064 – You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘TYPE=INNODB’ at line 11 “

If I remove the TYPE=INNODB in the end of create the tables, it will show the error:

“#1005 – Can’t create table ‘curriculo.info’ (errno: 150) “.

Answer 1

Use ENGINE = INNODB, not TYPE = InnoDB.

From MySQL docs, version 5.1, CREATE TABLE syntax:

Note

The older TYPE option was synonymous with ENGINE. TYPE has been deprecated since MySQL 4.0 but is still supported for backward compatibility in MySQL 5.1 (excepting MySQL 5.1.7). Since MySQL 5.1.8, it produces a warning. It is removed in MySQL 5.5. You should not use TYPE in any new applications, and you should immediately begin conversion of existing applications to use ENGINE instead. (See Section D.1.64, “Changes in MySQL 5.1.8 (Not released)”.)

---

If you want to have this Foreign Key:

FOREIGN KEY (email) REFERENCES users(email)

the users(email) should have a UNIQUE constraint. All Foreign Keys should reference either a Primary or a Unique Key. You want a row in the info table to reference (through the FK) one and only one user (row in the users table).

---

Best practise though (for various reasons) is to have narrow (small) and constant-wide columns as Foreign Keys. Your email is 100 characters which could be from 100 to 300 bytes (depending on the charset). So, you may consider using user_id as the FK, which is just 4 bytes wide:

CREATE TABLE info (
  ...
             ---- email varchar(100) NOT NULL default '',   
             ---- removed
  user_id int unsigned NOT NULL, 
  PRIMARY KEY  (info_id),
  FOREIGN KEY (user_id) REFERENCES users(user_id)
      ON UPDATE CASCADE ON DELETE CASCADE
) TYPE=INNODB;