Question

我有四张桌子：

锦标赛（id，name，slots，price，gameId，platformId）
游戏（身份证，姓名）
平台（id，name）
参与（id，tournamentId，playerId）

我想获得锦标赛的游戏名称，平台名称，位置，价格，reservedSlots（参与计数），是否某些玩家（他的id由php提供）参与此锦标赛（bool / true）的信息，条件是： - gameId必须在php提供的指定数组中 - platformId必须在php提供的指定数组中

我创建了类似的东西，但它无法正常工作：

PHP：

$platformsList = "'". implode("', '", $platforms) ."'"; // 
$gamesList = "'". implode("', '", $games). "'";

MySQL的：

    SELECT
    t. NAME AS tournamentName,
    t.id,
    t.slots,
    p. NAME,
    g. NAME AS gameName,
    t.price
FROM
    tournaments AS t,
    platforms AS p,
    games AS g,
    participations AS part
WHERE
    t.PlatformId = p.Id
AND t.GameId = g.Id
AND t.Slots - (
    SELECT
        count(*)
    FROM
        participations
    WHERE
        TournamentId = t.id
) > 0
AND part.TournamentId = t.Id
AND t.PlatformId IN ($platformsList)
AND t.GameId IN ($gamesList)

Answer 1

我不会喜欢处理你的帖子并获得价值观，我会认为一切都很好：

$possibleGameIDs = getPossibleGameIDs(); //function will return the array you need for possible game id values. Inside your function make sure that the id values are really numeric
$possiblePlatformIDs = getPossiblePlatformIDs(); //function will return the array you need for possible platform id values. Inside your function make sure that the id values are really numeric
$playerId = getPlayerId(); //function returns the player id and makes sure that it is really a number

$sql = "select games.name, platforms.name, tournaments.slots, tournaments.price, ".
       "(select count(*) from participations where participations.tournamentId = tournaments.tournamentId) as reservedSlots, ".
       "(select count(*) > 0 from participations where participations.tournamentId = tournaments.tournamentId and playerId = ".$playerId.") as isParticipating ".
       "from tournamens ".
       "join games ".
       "on tournaments.gameId = games.id ".
       "join platforms ".
       "on tournaments.platformId = platforms.id ".
       "where games.id in (".implode(",", $possibleGameIDs).") and ".
       "      platforms.id in (".implode(",", $possiblePlatformIDs).") and ".
       "      tournaments.slots > 0"

代码未经过测试，如果您在使用它时遇到任何问题，请告诉我。当然你需要运行它，但是因为你没有指定你用什么来运行查询，所以我没有分配时间来处理运行它的技术细节。但请注意SQL注入。

如何创建这样的查询？

1 个答案: