Question

what must exist on the parent table before my SQL will allow you to create a foreign key constraint in the child table.
what is the difference between a where clause and having clause of SQL select statement.
the absence of a break statement in the case of switch statement give rise to a mechanism known as?

Answer 1

hi mate ur answer.....

1)primaty key constraints...

2)where clause is used for any conditions it is used by update, delete... now having clause is used by GROUP BY COMMAND.....

3)fall through....

hope it help u mark me as brainlist.....

Answer 2

Explanation:

• primary key
• where clause used in all commands of SQL WHERE having clause is used for group by
• fall through