Evaluate the following SQL commands:
The command to create a table fails.
Identify the reason for the SQL statement failure? (Choose all that apply.)
A.
You cannot use SYSDATE in the condition of a CHECK constraint.
B.
You cannot use the BETWEEN clause in the condition of a CHECK constraint.
C.
You cannot use the NEXTVAL sequence value as a DEFAULT value for a column.
D.
You cannot use ORD_NO and ITEM_NO columns as a composite primary key because ORD_NO is
also the FOREIGN KEY.
Explanation:
CHECK Constraint
The CHECK constraint defines a condition that each row must satisfy. The condition can use the
same constructs as the query conditions, with the following exceptions:
References to the CURRVAL, NEXTVAL, LEVEL, and ROWNUM pseudocolumns
Calls to SYSDATE, UID, USER, and USERENV functions
Queries that refer to other values in other rows
A single column can have multiple CHECK constraints that refer to the column in its definition.
There is no limit to the number of CHECK constraints that you can define on a column.
CHECK constraints can be defined at the column level or table level.
CREATE TABLE employees
(…
salary NUMBER(8,2) CONSTRAINT emp_salary_min
CHECK (salary > 0),