To answer this question, let's understand the concept of UNIQUE KEY constraint and the behavior of SYSDATE.
A UNIQUE KEY constraint ensures that the values in a column or a group of columns are unique. It prevents duplicate values from being inserted into the column(s) that the constraint is defined on.
SYSDATE is a function in SQL that returns the current date and time. When you use SYSDATE in an INSERT statement, it will insert the current date and time into the specified column.
Based on this information, if a UNIQUE KEY constraint is created on a DATE column and you try to insert rows with SYSDATE, the constraint will not accept the rows. This is because each new row will have a different date and time value, which violates the uniqueness constraint.
Therefore, the correct answer is:
Option B) won't - This option is correct because when a UNIQUE KEY constraint is created on a DATE column, it will not accept rows that are inserted with SYSDATE.