ERROR 1054 (42S22): Unknown column 'stu.student_id' in 'on clause'解决办法： 需要把联合的表用括号括起来，并且括起来之后不能取别名: 正确写法 ：注意：括起来之后也不要起别名，不然也会报错
当你插入数据的时候 id获取到的是可能是null 你打个断点 跟踪下，看看是不是null
百度试题 题目将student表中的st_sex列属性更改为NOT NULL A. lter table student B. lter column st_sex nVarChar(2) not null 相关知识点: 试题来源: 解析 A.lter table student 反馈 收藏
ERROR 1054 (42S22): Unknown column 'stu.student_id' in 'on clause' 解决办法: 需要把联合的表用括号括起来,并且括起来之后不能取别名: 正确写法 : select*from(studentsasstu,subjectsassub)leftjoinexaminationsasex on stu.student_id=ex.student_id and sub.subject_name=ex.subject_name; 注意:括起来...
aYou need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task? 您在STUDENT_ID专栏需要修改学生桌增加一个主关键字。 桌当前是空的。 哪个声明完成这项任务?[translate]...
(no such column: users_student.user_id) was the direct cause of the following exception: File "C:\Users\KAVYA\Documents\Test-series-demo\venv\lib\site-packages\django\core\handlers\exception.py", line 47, in inner response = get_response(request) File "C:\Users\KAVYA\Documents\Tes...
a他是我们班第一个面临这个难题的学生 He is our class first faced with this difficult problem student[translate] a这是没礼貌的 这是没礼貌的[translate] a没骗我 Has not deceived me[translate] adid you know the tea 您知道茶[translate]
百度试题 题目修改student表,删除列beizhu。 A. lter table student drop column B. olumn be C. rop column beizhu; 相关知识点: 试题来源: 解析 A.lter table student drop 反馈 收藏
CREATETABLE[dbo].[tblstudent] ( [id][INT]IDENTITY(1,1)NOTNULL, [student_code][VARCHAR](20)NOTNULL, [student_firstname][VARCHAR](250)NOTNULL, [student_lastname][VARCHAR](10)NOTNULL, [address][VARCHAR](max)NULL, [city_code][VARCHAR](20)NOTNULL, ...
百度试题 题目以下能删除一列的语句是()A.alter table tb_student remove ageB.alter table tb_student drop column ageC.alter table tb_student delete column ageD.alter table tb_student delete age 相关知识点: 试题来源: 解析 B 反馈 收藏