Why doesnt this complex MySQL query work?

问题

I have 2 tables; members and teams

members table memberID, firstName, lastName

(firstName and lastName are fulltext indexes)

teams table team_id, member1ID, member2ID

Here's my query

$sql = "SELECT a.* ";       
$sql .= "FROM teams a WHERE ";
$sql .= "a.member1ID IN (SELECT b.memberID FROM members b ";
$sql .= "WHERE MATCH(b.firstName, b.lastName) AGAINST('$q' IN BOOLEAN MODE)) ";
$sql .= "OR a.member2ID IN (SELECT b.memberID FROM members b ";
$sql .= "WHERE MATCH(b.firstName, b.lastName) AGAINST('$q' IN BOOLEAN MODE)) ";

if($year)
    $sql .= "AND a.team_y = $year ";

$sql .= "ORDER BY a.team_num ASC "; 

if($limit)      
    $sql .= "$limit";

This query has to be close, but its not working yet.

Im trying to build a query that will let me show me all of the teams "$q" is on.

Ex. $q=doe , Show me all teams that doe is on.

This query has to output the teams.

回答1:

One possible reason your query doesn't work is there is a minimum length on full-text searching, which defaults to 4 characters. "doe" would fail this match. You can increase this via variable "ft_min_word_len"
http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html#sysvar_ft_min_word_len

By the way, if you want to avoid Normalizing (which isn't always the "best" way to go), you could at least use JOIN's instead of sub-selects.. e.g. (field names renamed to save on typing)

select t.* from teams t
inner join members me1 on t.m1 = me1.id
inner join members me2 on t.m2 = me2.id
where MATCH(me1.fname, me1.lname, me2.fname, me2.lname) 
    AGAINST('smith' IN BOOLEAN MODE);

回答2:

Normalize your database.

In your case, this would mean having a table Team (team_id, name, whatever else), a table Member (member_id, first_name, last_name), and a table MemberToTeam (member_id, team_id). In other words, move the member1ID and member2ID into their own table.

Following this practice, apart from "improving" your database schema in the general sense, means that the query that bothers you will become trivial to write.

If you know the member_id:

SELECT team_id FROM MemberToTeam WHERE member_id = 1

If you search by first or last name:

SELECT mtt.team_id FROM Member m
LEFT JOIN MemberToTeam mtt ON m.member_id = mtt.member_id
WHERE m.first_name LIKE '%your search string here%' OR m.lastname LIKE '%your search string here%'

来源：https://stackoverflow.com/questions/5211749/why-doesnt-this-complex-mysql-query-work

标签

php

mysql

database-normalization