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
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
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
百度试题 结果1 题目SQL语句:ALTERTABLESTU—DENTlCOLUMNXHINT,功能是将表STUDENTl的COLUMN列变成INT型的,应填入( )。A. CREATE B. ALTER C. INSERT D. DELETE 相关知识点: 试题来源: 解析 正确答案B 反馈 收藏
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] ...
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 ...
在此範例中,Student數據表最多 30 秒的讀取和寫入無法使用(使用MaxDowntimeInSeconds參數指定的值。假設數據行主要密鑰,保護MyCEK,會儲存在 Azure 外部(不需要傳遞 Azure 令牌)。 PowerShell $ces1=New-SqlColumnEncryptionSettings-ColumnName'dbo.Student.Id'-EncryptionType'Deterministic'-EncryptionKey'MyCek'$ces2...
java.sql.BatchUpdateException: Field 'stu_id' doesn't have a default value. I have tried manipulating the line pst = con.prepareStatement("insert into student(first_name,last_name,address) values (?,?,?)"); Other errors have occurred despite the addition of a 4th question mark in v...
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, ...
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]