Which two statements are true about the primary key constraint in a table? ()
What type of constraint is used to ensure that each row inserted into the EMPLOYEE table with a value in the WORKDEPT column has a row with a corresponding value in the DEPTNO column of the DEPARTMENT table?()
If a unique constraint is defined on column COL1 of table TAB1, what are the characteristics of COL1?()
Which syntax turns an existing constraint on?()
Which constraint can be defined only at the column level?()
A constraint in a table is defined with the INITIALLY IMMEDIATE clause. You executed the ALTER TABLE command with the ENABLE VALIDATE option to enable the constraint that was disabled. What are the two effects of this command?()
下列哪项属于约束理论(TOc, Theory of Constraint)的主要关注领域?()
评估以下语句: ALTER TABLE employees ADD CONSTRAINT employee_id PRIMARY KEY; 该语句将返回以下哪种结果()
Which four are valid Oracle constraint types? ()
Which statement explicitly names a constraint?()