In MySQL database, the two data written when creating tables with foreign keys are the same. Do I copy them or fail to display them

The input is the same ,

Problem related code , Do not paste screenshots

Operation results and error reporting contents

My solution ideas and tried methods

What I want to achieve

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Take the answer ：

brother , Really? , This thing has been bothering you for two days now ...
:(
Every time I don't write something wrong , But not careful .
Do development , Be calm , take your time , Look at your last line ,clasno Is there one missing s, Should be classno That's right ..

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