Question

i want to do for a table something like this.
I have two tables one with a foreign key(id) and second table where i hold data that coresponds to the first table.
My problem is that for each entry i might have one or two even more groups that belongs too.
Is it posible to do something like this:
table1 – id(foreign key) table2 – entry1 – table1.id1, table1.id2
And if it is posible can you explain how should i do?

CREATE  TABLE IF NOT EXISTS `network`.`dbo.networkNodes` (
  `nodeId` INT(11) NOT NULL AUTO_INCREMENT ,
  `nodeName` VARCHAR(45) NULL ,
  PRIMARY KEY (`nodeId`) )
ENGINE = InnoDB


CREATE  TABLE IF NOT EXISTS `network`.`dbo.networkIps` (
  `networkIpId` INT(11) NOT NULL AUTO_INCREMENT ,
  `nodeId` INT(11) NULL ,
  `networkIp` INT(20) NULL ,
  PRIMARY KEY (`networkIpId`) )
ENGINE = InnoDB

Answer 1

I think you’re asking for either a many-to-many relationship, or multiple, defined one-to-many relationships, so it depends on the use.

A many-to-many relationship would actually require an intermediate table, containing an ‘id’ field pointing to each of the two tables:

CREATE TABLE networkNodes (
    nodeId int(11) NOT NULL AUTO_INCREMENT,
    nodeName varchar(45) NULL,
    PRIMARY KEY (nodeId)
);

CREATE TABLE networkIps (
    networkIpId int(11) NOT NULL AUTO_INCREMENT,
    networkIp int(20) NULL,
    PRIMARY KEY (networkIpId)
);

CREATE TABLE netowkNodesIps (
    nodeId int(11) NOT NULL,
    networkIpId int(11) NOT NULL,
    PRIMARY KEY (nodeId, networkIpId)
);

If you would rather add multiple one-to-many relationships, the specific relationship ‘reason’ should be contained in the name of the foreign key.