Mysql 如何选择最多两列的位置
我创建了一个视图,以便继续使用它,而不必每次视图调用“Data”时都编写这部分代码Mysql 如何选择最多两列的位置,mysql,sql,inner-join,where,Mysql,Sql,Inner Join,Where,我创建了一个视图,以便继续使用它,而不必每次视图调用“Data”时都编写这部分代码 第一条SQL语句将为特定用户获取每个系列的最大季节 SELECT s_imdbID, MAX(ep_season) FROM Data WHERE u_ID = 1 GROUP BY s_imdbID SELECT s_imdbID, ep_season, MAX(ep_episode) FROM Data WHERE ep_season = ( SELECT MAX(ep_season)
第一条SQL语句将为特定用户获取每个系列的最大季节
SELECT s_imdbID, MAX(ep_season) FROM Data
WHERE u_ID = 1
GROUP BY s_imdbID
SELECT s_imdbID, ep_season, MAX(ep_episode) FROM Data
WHERE ep_season = (
SELECT MAX(ep_season)
FROM Data
WHERE u_ID = 1
AND s_imdbID = "tt4158110"
)
AND s_imdbID = "tt4158110"
AND u_ID = 1;
第二条SQL语句将为特定用户获取最新一季的最新剧集
SELECT s_imdbID, MAX(ep_season) FROM Data
WHERE u_ID = 1
GROUP BY s_imdbID
SELECT s_imdbID, ep_season, MAX(ep_episode) FROM Data
WHERE ep_season = (
SELECT MAX(ep_season)
FROM Data
WHERE u_ID = 1
AND s_imdbID = "tt4158110"
)
AND s_imdbID = "tt4158110"
AND u_ID = 1;
如何将它们集成到一个SQL语句中以获得以下内容seriesID | Max_Season | Max_Episode
-----------| ------------------| -----------
Value.... | Value............ | Value
这是查看代码在代码中,您将能够知道将从中检索的数据类型
SELECT
-- episode data
e.title AS "ep_title",
e.year AS "ep_year",
e.rated AS "ep_rated",
e.released AS "ep_released",
e.season AS "ep_season",
e.episode AS "ep_episode",
e.runtime AS "ep_runtime",
e.genre AS "ep_genre",
e.director AS "ep_director",
e.writer AS "ep_writer",
e.actors AS "ep_actors",
e.plot AS "ep_plot",
e.language AS "ep_language",
e.country AS "ep_country",
e.awards AS "ep_awards",
e.poster AS "ep_poster",
e.metascore AS "ep_metascore",
e.imdbRating AS "ep_imdbRating",
e.imdbVotes AS "ep_imdbVotes",
e.imdbID AS "ep_imdbID",
-- series data
s.title AS "s_title",
s.year AS "s_year",
s.rated AS "s_rated",
s.released AS "s_released",
s.runtime AS "s_runtime",
s.genre AS "s_genre",
s.director AS "s_director",
s.writer AS "s_writer",
s.actors AS "s_actors",
s.plot AS "s_plot",
s.language AS "s_language",
s.country AS "s_country",
s.awards AS "s_awards",
s.poster AS "s_poster",
s.metascore AS "s_metascore",
s.imdbRating AS "s_imdbRating",
s.imdbVotes AS "s_imdbVotes",
s.imdbID AS "s_imdbID",
-- user data
u.ID AS "u_ID"/*, */
/*
u.username AS "u_username",
u.firstname AS "u_firstname",
u.lastname AS "u_lastname",
u.password AS "u_password",
u.email AS "u_email",
u.emailVerificationCode AS "u_emailVerificationCode",
u.location AS "u_location",
u.accesslevel AS "u_accesslevel",
u.disabled AS "u_disabled",
u.active AS "u_active"
*/
FROM test w
INNER JOIN users u
ON u.ID = w.userid
INNER JOIN episode e
ON w.epid = e.imdbID
INNER JOIN series s
ON e.seriesID = s.imdbID
WHERE e.seriesID IN (SELECT (imdbID) FROM series);
编辑1:这是一个系列的观察列表,视图数据来自一个表,在该表中,我用它所观察的事件保存每个用户
通过该视图,我获得了插曲、系列、用户的数据您可以尝试使用
NOT EXISTS()
:
第一个确保没有新的一季,第二个确保没有新的一集