CodePudding user response:

Increase the column of SQL is wrong?

The alter table couse the add cnam says varchar (10);

CodePudding user response:

I can't read what you wrote I am just learning this thing is not too deep

CodePudding user response:

refer to the second floor u014249415 response:

I can't read what you wrote I am just learning this thing is not too deep

Your grammar is wrong

CodePudding user response:

Add columns moderator wrote
If is the only constraint is:
The alter table couse the add constraint uq_couse unique (cnam says)

CodePudding user response:

If the grammar is wrong, the DB will be an error in your grammar is wrong, but there is no similar mistakes,

Maybe you 'cname, does not exist,