Question

How would you reference table1 columns to 2 columns in table 2

I created a table ‘State‘ with 50 exact rows

trying to relate (weddingState,contactState) in ‘Wedding‘ table

This is the statement that I created but it only joins the top WeddingState correctly – seems not to care about the INNER Join below it…

SELECT *

FROM weddings

INNER JOIN states as s1 ON weddings.WeddingState = s1.StateId //state of marriage

INNER JOIN states as s2 ON weddings.ContactState = s2.StateId //contact state of bride

WHERE weddings.weddingid=’094829292′

Answer 1

I’d guess that you’re retrieving these in PHP or something, and you’re fetching the rows in a hash-array, keyed by the field name. Of course there can only be one element in a hash with a given key. So you need to use column aliases to make sure columns with the same name are given a distinct alias.

SELECT w.*, s1.StateID AS wstate, s2.StateId AS cstate FROM weddings AS w INNER JOIN states AS s1 ON w.WeddingState = s1.StateId //state of marriage INNER JOIN states AS s2 ON w.ContactState = s2.StateId //contact state of bride WHERE w.weddingid='094829292'; 

Now your hash-array will have keys ‘wstate’ and ‘cstate’. Without aliasing these columns, one will always overwrite the other.