我有两张table。i)订单详情:CREATETABLE`order_details`(`id`INT(11)NOTNULLAUTO_INCREMENT,`content`text,`id_employee`INT(11)DEFAULTNULL,PRIMARYKEY(`id`),KEY`FK_id_employee`(`id_employee`),CONSTRAINT`FK_id_employee`FOREIGNKEY(`id_employee`)REFERENCES`employees`(`id`))ENGINE=InnoDBAUTO_INCREMENT=4DEFAULTCHARSE
您好，我正在使用Java前端和Mysql后端，,,其实在tbl_test中包含namevalue---------------abc22xyz14ABC32xyZ4ABc4在java中我尝试检索abc的值所以写了一段代码ResultSetresult=stmt.executeQuery("selectvaluefromtbl_testwherename='abc'");while(result.next()){System.out.println("Answer:"+result.getInt(1));}result.close();当前输出为Answer:22Answer:32Ans
我想知道为什么这个查询仍然可以完美运行。我认为WHERE子句总是必须以WHERE开头？SELECT`persons`.*FROM`persons`LEFTJOIN`team_memberships`ON(`team_memberships`.`participant`=`persons`.`id`)JOIN`teams`ON(`teams`.`id`=`team_memberships`.`team`)JOIN`departments`ON(`departments`.`id`=`teams`.`department`)JOIN`areas`ON(`areas`.`id`=`depar
医生doctorid(PK)doctornamePatientpatientid(PK)patientnamedoctoridIhavethefollowingquerytogetthedoctorsdetailswiththenumberofpatientsthathe/sheconsults.assumeapatienthasonlyonedoctortoconsult.selectd.doctorid,d.doctorname,count(p.patientid)fromdoctordinnerjoinpatientpond.doctorid=p.doctoridgroupbyp
selectid,title,release_datefromtbl_movieswhererelease_date>'2014-02-20'orrelease_date=''orderbyrelease_dateasc"id"|"title""release_date""49"|"Fandry"|"""92"|"Govinda"|"""112"|"GadadJambhal"|"""114"|"AandhaliKoshimbir"|"""118"|"MeeAaniU"|"""125"|"Tapal"|"""131"|"Cappuccino"|"""129"|"SauShashiDeod
我想在mysql查询的wherein条件中包含可能的值作为null。这是我的查询:但它没有显示任何值。请建议我如何在WHEREIN条件中包含空值。SELECT*FROMTABLE1WHERECOLUMN1IN('YES','NO',NULL); 最佳答案 尝试类似的东西:SELECT*FROMTABLE1WHERE(COLUMN1IN('YES','NO')ORCOLUMN1ISNULL)此处的in语句将被解析为COLUMN1='YES'或COLUMN1='NO'或field='NULL'。将NULL放入其中将使您得到COLUMN1
我在mysql中有以下两个表:用户:+--------+-----------+|userId|userName|+--------+-----------+|1|magnus||2|fabiano||3|alexander||4|veselin|+--------+-----------+游戏:+--------+---------+---------+|gameId|userId1|userId2|+--------+---------+---------+|1|1|2||2|1|3||3|2|3||4|2|4|+--------+---------+---------+我怎样才能
我没有找到yii2查询构建器yii\db\Query的任何示例，其中in运算符与where子句一起使用。暂时我是这样用的$result=(new\yii\db\Query)->select('*')->from('customerc')->where('c.statusin('.implode(',',[0,1]).')')->all();但是必须有更好的方法来做到这一点。提前致谢 最佳答案 $result=(new\yii\db\Query)->select('*')->from('customerc')->where(['c.s
我正在尝试编写一个mysql查询，其中where条件为(WHEREdate!='0000-00-00')。但是查询没有正确执行。WHEREdate!='0000-00-00' 最佳答案 首次将日期转换到char。然后尝试。WHERECAST(`date`ASCHAR(10))!='0000-00-00'或WHERE`date`!=0或WHEREUNIX_TIMESTAMP(`date`)!=0或WHERE`date`ISNOTNULL或WHEREYEAR(`date`)=0 关于Mysq
我正在尝试创建一个聊天应用程序，我想调出用户1和2的对话。表:+----+---------------------+-----------+---------+|id|message|from_user|to_user|+----+---------------------+-----------+---------+|1|hellotrick|1|2||2|hirafiamokay|2|1||3|howisjodoing|1|2||4|Hey|2|3||5|sheisdoingwell|2|1||6|howiskcdoing|2|1|+----+------------------
