JDBC with Mysql: using mulitple outer joins with where clauses - mysql

Question

I'm having an issue with the following query. It works in mysql workbench but not when I use it in java with jdbc. I keep getting a syntax error.
Here is the query:
"SELECT f.ISBN, f.text, m.title, AVG(r.rating) as score" +
" FROM RATES r LEFT OUTER JOIN FEEDBACK f ON (f.fid = r.fid) WHERE f.ISBN = ? " +
"LEFT OUTER JOIN MOVIE m ON (m.ISBN = f.ISBN) " +
"GROUP BY ISBN " +
"ORDER BY score DESC LIMIT ? ";
I did some searching and found a jdbc escape syntax of {oj }. But I would get another syntax error.
The error I am getting lately is:
HTTP Status 500 - javax.servlet.ServletException:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an
error in your SQL syntax; check the manual that corresponds to your
MySQL server version for the right syntax to use near 'LEFT OUTER JOIN
MOVIE m ON (m.ISBN = f.ISBN) GROUP BY ISBN ORDER BY score DESC L' at
line 1
I would love some fresh eyes on this since I can't seem to see my issue.
Thanks in advance!

Answer 1

I think that WHERE clause has to be placed behind JOINING. And next problem is that number of columns in select clause has equal to number of columns in group clause(except functions as avg, count etc.). So you need to correct your query like this:
SELECT f.ISBN, f.text, m.title, AVG(r.rating) as score
FROM RATES r
LEFT OUTER JOIN FEEDBACK f ON (f.fid = r.fid)
LEFT OUTER JOIN MOVIE m ON (m.ISBN = f.ISBN)
WHERE f.ISBN = ?
GROUP BY f.ISBN, f.text, m.title
ORDER BY score DESC LIMIT ?

Answer 2

The left join must be before the where clause. And every column listed in the select clause should be in the group by clause:
SELECT f.ISBN, f.text, m.title, AVG(r.rating) as score
FROM RATES r
LEFT OUTER JOIN FEEDBACK f ON (f.fid = r.fid)
LEFT OUTER JOIN MOVIE m ON (m.ISBN = f.ISBN)
WHERE f.ISBN = ?
GROUP BY f.ISBN f.text, m.title
ORDER BY score DESC
LIMIT ?