Which three are true about dropping columns from a table? (Choose three.)
Which three are true about dropping columns from a table? (Choose three.)
A primary key column cannot be dropped without first removing the primary key constraint, making B true. Multiple columns can be dropped simultaneously using the ALTER TABLE command, making C true. A column drop is implicitly committed, making F true. Other options either contain conditions under which the statements are not always true or require additional actions (such as cascading constraints) to hold true.
E is partial correct because you can use ON DELETE clause
Yes, it is possible to drop this type of column with : ALTER TABLE tableName DROP COLUMN colName CASCADE CONSTRAINT;
For E, using cascade constraints, I was able to delete a primary key column that was referenced by a foreign key. C and F seem like the only truly correct options.
CF are the most correct, the other options have some special cases
If use have on delete then E is indeed right
CEF for me
You can drop a column that is referenced by another column with CASCADE CONSTRAINTS clause (E), so I only find here 2 correct answers (CF)