Question

我一直在改变我的所有表格,以界定科索沃解放阵线,在试图让这个表系的学生出现错误。 Rsp 。

ALTER TABLE StudentRsp
add CONSTRAINT fk_rspDate
  FOREIGN KEY (rspDate)
  REFERENCES LecturerRsp(rspDate);

重犯错误

Error Message: There are no primary or candidate keys in the referenced table LecturerRsp that match the referencing column list in the foreign key fk_rspDate . Could not create constraint. see previous errors.

学生会被定义为讲师的主要关键人物

Answer 1

看看贵国学生学习成绩,在你的讲师席上没有这方面的领域。换言之,这一限制要求根基的关键一栏中的所有领域都与主要一栏的某个领域相匹配,而学生学习成绩中有一个关键之处,在讲师中就不存在。

例:

LecturerRsp         StudentRsp
 pk_Col1             fk_Col1
  1                     1
  2                     2
  3                     4
  4                     5 ***

Answer 2

错误信息非常清楚,只是读到......。

*There are no primary or candidate keys in the referenced table LecturerRsp that match the referencing column list in the foreign key fk_rspDate .*

You want to reference your table LecturerRsp and its column rspDate - but this message clearly tells you: rspDate is not the primary key on that table, nor is it part of a unique index/constraint.

这两条都要求你能够从外国钥匙中提一栏。

To fix this:

either change the primary key on LecturerRsp to be on column rspDate
or (if possible) create a unique index on that column

If you cannot do either of these two things, then you cannot reference that column from a foreign key.

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