howdy ya'll,

newbie here and I'm working my way through The Complete SQL Bootcamp: Zero to Hero by Jose Portilla on Udemy.

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I'm confused as to how to go about adding or dropping a foreign key constraint on an already existing table for a single column. In the lecture he uses SET and DROP, with ALTER TABLE but then also briefly mentions ADD CONSTRAINT but doesn't differentiate when to use which one.

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For example, I have 3 tables. One called teachers, one called students, and I tried making a third called stu_tea that just combines Teacher_id from teachers, and student_id from students. Obviously I could have done the foreign key stuff initially when creating stu_tea, but I wanted to see how it could be done after the fact.

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I can't for the life of me figure out how to DROP the foreign key part.

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To add one I got the following to work:

ALTER TABLE stu_tea
ADD FOREIGN KEY (teacher_id)
REFERENCES teachers(teacher_id);

but how would I drop that same constraint?

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I've tried googling it, and only ended up more confused after trying every possible syntax I could find.

Any help and explanation is MUCH appreciated!

Happy Holidays Ya'll