发生什么事了

没有数据库选择 应该怎么搞

INSTR中的"Contains 'a'?"不懂

不太懂为什么能直接绑定一千条参数？在ITBZ后面＋i代表什么意思？

SELECT e.LAST_NAME,e.DEPARTMENT_ID 

from employees e

 WHERE e.DEPARTMENT_ID=(SELECT e1.DEPARTMENT_ID 

from employees e1  where e1.last_name"Fox");

老师我这串代码哪里有问题呀

物理空间是磁盘空间吗？？？？？？

 `userage` int(11) DEFAULT NULL,

 PRIMARY KEY (`userid`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

受影响的行: 0

时间: 0.010s

[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column 'information_schema.PROFILING.SEQ' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

老师我这里面没有my.ini文件

老师为什么我创建的文件图标不对啊

mysql的语言好多，经常学了又忘怎么办

我在navicat添加外键输入mysql语句后报错

[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column ‘information_schema.PROFILING.SEQ’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by，可是外键还是成功添加了，这是啥错误啊？

第四题和第六题是不是用两个表的等值连接，然后再根据条件查找也能实现题目要求

运行的时候成功了但是表里没加上数据

哪里出错了

这里为啥报错了