mysql - Issues setting up a N-M relationship -


Using MySQL, I try to install multiple relationships from 1 by using already uploaded data in the database I am doing For example, say I have a list of names in a table and I want to add them to the lists of places that they are, obviously 1 person can go to many different places, but let me set up this set up There is a problem taking place.

  ----- Name ----------- ID --------- John Smith 1 Random 2 Seth Boy 3 ---- --------------------------  

I have another table which will look like this:

  ------- City --------- ID --- ------ New York 1 Chicago 2 Orlando 3 La 4 ------- ------------------------  

I am looking for something like this:

  -------- name -------- city ---------- John Smith Chicago John Smith Orlando John Smith New York Seth Guy Chicago who randomized LA - ----------------------------- ------  

I know That John Smith has been in all three places because the original file I upload tells me so much, but I want the database to make that connection and accordingly accordingly keep it accordingly. As described in the observations, it is an N-M relationship, not a 1-N relationship, it

You need an additional "mapping" table to record visits:

  create table visits (person Iid INT, city_id INT, contract visits_pack primary key (person_id, city_id)); After that, you can query all visits with something added:  
  select the person. Name, city People by name add visits to the person. ID = Visits Visit on PRSN_ID city. City_ID = city.id  

Comments

Popular posts from this blog

java - Can't add JTree to JPanel of a JInternalFrame -

javascript - data.match(var) not working it seems -

javascript - How can I pause a jQuery .each() loop, while waiting for user input? -