我做了一个LEFT JOIN来从我的数据库中获取2个表的值.查询是这样的：SELECT * FROM threadLEFT JOIN comments ON thread.id_thread = comments.id_thread WHERE id_type = '1' ORDER BY data DESC, hour DESC然后我以这种方式输出值：<?while($row = mysqli_fetch_array($query)) { echo '<div class="col-md-1"></div>'; echo '<div class="col-md-11">'; echo $row['title'] ."<br><br>".$row['content']."<br><br>"; echo $row...
目前我正在使用’users’表加入’articles’表.我只想加入字段’fullName’,而不是加入’users’表中的所有字段. 这可能吗？我一直在寻找解决方案,但没有太多运气.这是我目前的SQL语句：SELECT * FROM articles LEFT JOIN users ON articles.uid=users.uid谢谢解决方法:只需将*更改为所需列的列表即可SELECT articles.*, users.fullName FROM articles LEFT JOIN users ON articles.uid=users.uid
我有两张桌子,一张用于机场,一张用于路线. 机场看起来有点像这样Airports ------------------------------------- id | code | name | ------------------------------------- 01 | LGW | London Gatwick | ------------------------------------- 02 | LHR | London Gatwick |等等…. 和另一个像这样的路线Routes --------------------------- id | ORIGIN | DESTINATION | -------------...
下面的查询返回一组User,并且对于每一行,来自正在搜索的用户的一些关系(id = 4)SELECT `users`.`firstname` AS firstname,`users`.`lastname` AS lastname,COUNT(`trusted_users`.`id`) AS number_of_friend_in_common,CASE ... AS friend,CASE ... AS facebook_invitable,CASE ... AS address_book_invitable,CASE ... AS virtual_user, FROM `users`LEFT OUTER JOIN `trusted_users` ON `trusted_users`.`user_id` = 4 AND `trus...
我有一个类似于下面简化的数据库.我需要检索列：col8,col9,col10,col11,col12(我圈出的那些 目前,我使用左连接来连接每个表,但这会导致查询耗时很长(有很多记录).在分析时,最大的影响是写入tmp表. 我将结果限制为24,但由于左连接,它仍然将数千条记录复制到tmp表. http://oberto.co.nz/demo/assets/db2.jpeg 这可以优化,以便仍然使用pk的连接从每个表中检索带圆圈的列吗？ 谢谢.解决方法: SELECT a.col12, b1.col8, c1.col9, d1.col...
假设我有2个表： leave_typeid name 1 maternity leave 2 Medical leave 3 Casual Leave 4 Sick Leave 5 honeymoon Leaveemployee_leave_blanceid employee_id year leave_type_id val 1 4 2015 1 9 2 4 2015 2 5 3 8 2015 1 10 4 ...
我有三张桌子 驱动程序driver_id | driver_name |driver_number----------------------------------------1 | Driver 1 | 999992 | Driver 2 | 88888每个司机都有班次shift_id | start_time | end_time | driver_id -----------------------------------------------------------------4 |2015-04-02 10:09:00 |(NULL) | 13 |2015-04-02 09:19:00 |(NULL...
我有2个表,其中一个存储学生,另一个存储管理员 学生姓名,最终管理者也有名字和姓氏. 我还在学生表中存储了added_by,以检查添加了学生的经理. 随着查询我连接表$students = \App\Student::with('payment')->with('discontinuities')->leftJoin('managers','students.added_by','=','managers.id')->get();让我们说学生是Name Surname Added_by Jon Doe 1和经理是id name surname 1 jane doe所以当我用上面给出的查询加入这两...
我有3张桌子,我已经离开了,但是我想从表格3中添加一个字段,它与表格2连接在一起.Table1 id name surname table2_fkTable2 id entry_name entry_code table3_fkTable3 id type_name type_descSELECT `Name`, `Type Description` (SELECT Table1.name AS `Name`, Table1.surname AS `Surname`, t2.entry_name AS `Entry`, t2.entry_code AS `Entry Code`, t3.type_name AS `Type Name`, t3.type_desc AS `Type Description`FROM Tabl...
我在查询中使用多个左连接时有点麻烦.有些表与左表有一对一的关系,有些与一对多关系.查询如下所示：Select files.filename,coalesce(count(distinct casewhen dm_data.weather like '%clear%' then 1end),0) as clear,coalesce(count(distinct casewhen dm_data.weather like '%lightRain%' then 1end),0) as lightRain,coalesce(count(casewhen kc_data.type like '%bicycle%' then 1end),0) as bicycle,coalesce(count(casewhen ...
为了简化我的问题：假设我有3个表.Rooms People Things -------- -------- -------- id| name id | name | fk_rooms id | name | fk_rooms ----------- --------------------- --------------------- 1 | kitchen 1 | John | 1 1 | TV | 2 2 | bedroom 2 | Mary | 2 2 | bed | 23 | Andy | ...
我有一个表引用城市表的表,其中一个键叫做cityId.我使用此查询从中获取数据：SELECT t.ID, city.areaId FROM transp t LEFT JOIN city ON city.ID = t.cityId;像这样,它按原样返回表,对于city.areaId为NULL,如果cityId为null. 但是当我将函数添加到使用city.areaId的where子句时,即使是始终为true的函数,查询也不会显示cityId为null的行.例如：SELECT t.ID, city.areaId FROM transp t LEFT JOIN city ON city.ID = t.cityId WHERE...
我试图在MySQL中做一个非常复杂的查询;对我来说很复杂,至少. 这是我正在尝试做的一个例子：SELECT * FROM friends LEFT JOIN users ON users.uid = friends.fid1 LEFT JOIN users ON users.uid = friends.fid2 WHERE (friends.fid1 = 1) AND (friends.fid2 > 1) UNION SELECT fid2 FROM friends WHERE (friends.fid2 = 1) AND (friends.fid1 < 1) ORDER BY RAND() LIMIT 6;我回来了：ERROR 1066(42000)：不是唯一的表/别名：’use...
我有2张桌子：Table1: ID | Mobile Number | Name | Ordered Product| Order Date表2：ID(foreign_key can be inserted multipletimes in this table) |Contacted_for | Time(timestamp)我需要一个查询来显示Table1中的所有数据,如果表2中有ID,我需要显示该ID的Table2(随时间)的最后插入记录 我的疑问是select a.* , b.* FROM table1 a LEFT JOIN table2 b ON a.ID=b.ID GROUP BY a.ID ORDER BY b.Time DESC在我的查询中,当我删除G...
我有两张桌子,我想参加…即营地和城市.我已经用PHP编写了这个查询…但是我想要Yii2格式的相同查询…请告诉我如何在yii2中编写这个查询… ?? 这是我的查询：SELECT DISTINCT camps.city_id, camps.state_id, cities.city_name from camps LEFT JOIN citiesON cities.state_id = camps.state_idWHERE camps.state_id = 5AND camps.status = '1'ORDER BY cities.city_name ASC解决方法: use yii\db\Query;$query = new Query(); $qu...