Ambiguous left join?

so I'm struggling with what I'm guessing is a very simple problem. I've searched around a bit, but none of the solutions I've found so far have worked on my problem.

SELECT arrangement_ID, hva, dato 
FROM tt_arrangement LEFT JOIN (tt_vaktliste_v开发者_运维问答akt)
ON (tt_arrangement.arrangement_ID = tt_vaktliste_vakt.arrangement_ID)

This naturally produces the "ambiguous error", since the column 'arrangement_ID' is present in both tt_arrangement and tt_vaktliste_vakt. Thinking this was easy to fix, I made the following changes:

SELECT **arrangement_ID.tt_arrangement**, hva, dato 
FROM tt_arrangement LEFT JOIN (tt_vaktliste_vakt)
ON (tt_arrangement.arrangement_ID = tt_vaktliste_vakt.arrangement_ID)

However, this produced the error "column doesn't exist". And that's where I'm stuck. Not sure if it matters, but when using SELECT * the query works as intended. Though that is not really an option for what I'm going to use the query for.

In advance, thanks for any replies.

Prefix the ambiguous column name with the tablename:

SELECT t_arrangement.arrangement_ID, hva, dato  
FROM tt_arrangement LEFT JOIN (tt_vaktliste_vakt) 
ON (tt_arrangement.arrangement_ID = tt_vaktliste_vakt.arrangement_ID) 

(assumes hva, dato are unique column names)

(You can also use aliases, but will still need to prefix ambiguous column names with alias)

You need to give your table names an alias, like below.

SELECT a.arrangement_ID, a.hva, a.dato 
FROM tt_arrangement  AS a
LEFT JOIN tt_vaktliste_vakt AS v
ON (a.arrangement_ID = v.arrangement_ID)

Not sure is the top lines right as i don't know you table structure so can't know which column comes from where.

Hopes this helps.