Question

I have a big query with a lot of inner join inside in a page on my website.
I want to apply for some left outer join limit 1 but if I put it into the sql give me errors.

This is a small part of my query isn’t total, this query is only a part and ISN’T FINISH:

SELECT * FROM products 
               LEFT OUTER JOIN  (origins 
                        LEFT OUTER JOIN  origin_aliases ON origin_aliases.origin_id = origins.id 
                        AND origin_aliases.language = '$lang'
                        LEFT OUTER JOIN  (diets LEFT OUTER JOIN  diet_aliases ON diet_aliases.diet_id = diets.id AND diet_aliases.language = '$lang') 
                        ON origins.diet_id = diets.id) 
                ON products.origin_id = origins.id
                LEFT OUTER JOIN  (product_aliases 
                        LEFT OUTER JOIN  (users as users1
                            LEFT OUTER JOIN  profiles as profiles1 ON profiles1.user_id = users1.id
                            LEFT OUTER JOIN  user_options as user_options1 ON user_options1.user_id = users1.id 
                            LEFT OUTER JOIN  avatars as avatars1 ON avatars1.user_id = users1.id
                        ) 
                        ON  product_aliases.user_id =users1.id
                        LEFT OUTER JOIN  (users as users2
                            LEFT OUTER JOIN  profiles as profiles2 ON profiles2.user_id = users2.id
                            LEFT OUTER JOIN  user_options as user_options2 ON user_options2.user_id = users2.id
                            LEFT OUTER JOIN  avatars as avatars2 ON avatars2.user_id = users2.id 
                        )  
                        ON  product_aliases.edit_user_id = users2.id)
                ON product_aliases.product_id = products.id  

…..

For example I want to apply limit 1 in the left outer join in origins after ON 'products.origin_id'='origins.id' is possible? How can I do this?
I have tried to put after the on condition limit 1 but give me an error

Syntax error or access violation: 1064 You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version
for the right syntax

Answer 1

As written, your example is full or errors. Your derived tables do not have SELECT clauses, you have quoted the table and column references, and it’s not clear if names like origins and origin_aliases are tables or aliases. Those are your syntax errors.

Once you correct those, you can add the LIMIT expression to the entire query or to any of the derived tables. Here is my best guess:

SELECT * 
FROM products 
LEFT OUTER JOIN ( 
   select *
   from   origins 
   LEFT OUTER JOIN origin_aliases 
   ON     origin_aliases.origin_id = origins.id 
      AND origin_aliases.language = '$lang' 
   LEFT OUTER JOIN ( 
      select *
      from   diets 
      LEFT OUTER JOIN  diet_aliases 
      ON     diet_aliases.diet_id = diets.id 
         AND diet_aliases.language = '$lang'
      ) d
   ON origins.diet_id=d.id

   LIMIT 1
   ) a
ON products.origin_id=a.id

I choose to use two table aliases (a and b). And I’m assuming that origins, origin_aliases, and diets are tables. Note you should not use SELECT *; provide the column names you want from each derived table as well as in your main SELECT clause.