PHP三个SQL选择语句

Question

i have one database with three tables and i am trying to get some information for all the tables

activities -> contains events/ acivities and uses the userIds of another table to identify the row.

teams -> contains a listing of teams (including the id stored in activities) and the attributed assigned to each team such as name away colors etc.

facilities -> contain list of all the facilities activities can be booked at

I would like to create a select statement that uses the activities table to get the home and away teams then look up the teams names (not ids which is stored in the activities database) and get the name of the facility .

i have used the following sql

$select = "SELECT *, teams.name 
            FROM activities, teams 
            WHERE (SELECT * 
                    FROM teams 
                    WHERE teams.id=activities.teamIdAway) activities.status=(:s) 
                AND activities.dateStart >= (:start) 
                AND activities.dateEnd <= (:end) 
                AND activities.facilityId=(:f)";

Answer 1

You need to do two join with the teams table, one for the home team, another for the away team.

SELECT f.name, ht.name AS hometeam, at.name AS awayteam
FROM facilities AS f
JOIN activities AS a ON a.facilityId = :f
JOIN teams AS at ON at.id = a.teamIdAway
JOIN teams AS ht ON ht.id = a.teamIdHome
WHERE a.dateStart >= :start
AND a.dateEnd <= :end
AND a.status = :s