SQL Many-to-Many Relationship Between Multiple Tables

Question

I have a database I\'m trying to create on SQL and I am trying to connect the relationships together. There are three tables: superhero, power, and superheroPower. The tables su

Answer 1

Your design seems on the right track, this is the tables i would have gone with - adding some Indexes for the fields its likely that you will search for and adding the actions needed for the CONSTRAINT keys

CREATE TABLE `_superhero` (
  `id` int(11) NOT NULL auto_increment,
  `heroName` varchar(255) NOT NULL,
  `firstName` varchar(255) default NULL,
  `lastName` varchar(255) default NULL,
  `firstAppearance` date default NULL,
  `gender` enum('Other','Female','Male') default NULL,
  `bio` text,
  `universe` varchar(255) default NULL,
  PRIMARY KEY  (`id`),
  KEY `indxHname` (`heroName`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `_power` (
  `id` int(11) NOT NULL auto_increment,
  `name` varchar(255) NOT NULL,
  `description` text NOT NULL,
  PRIMARY KEY  (`id`),
  KEY `indx4` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `_superheropower` (
  `superheroID` int(11) NOT NULL default '0',
  `powerID` int(11) NOT NULL default '0',
  PRIMARY KEY  (`superheroID`,`powerID`),
  KEY `indx1` (`superheroID`),
  KEY `indx2` (`powerID`),
  CONSTRAINT `fk2` FOREIGN KEY (`powerID`) REFERENCES `_power` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION,
  CONSTRAINT `fk1` FOREIGN KEY (`superheroID`) REFERENCES `_superhero` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=utf8;