多项选择题
In which three cases would you use the USING clause?（）
A.You want to create a nonequijoin.
B.The tables to be joined have multiple NULL columns.
C.The tables to be joined have columns of the same name and different data types.
D.The tables to be joined have columns with the same name and compatible data types.
E.You want to use a NATURAL join, but you want to restrict the number of columns in the join condition.
相关考题
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多项选择题
Which two tasks can you perform using only the TO_CHAR function? （）
A.convert 10 to 'TEN'
B.convert '10' to 10
C.convert 10 to '10'
D.convert 'TEN' to 10
E.convert a date to a character expression
F.convert a character expression to a date -
单项选择题
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employee_id NUMBER, name VARCHAR2(30)); INSERT INTO new_emp SELECT employee_id , last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id =180; UPDATE new_emp set name = James; Rollback to s2; UPDATE new_emp set name = James WHERE employee_id =180; Rollback; At the end of this transaction, what is true?（）
A.You have no rows in the table.
B.You have an employee with the name of James.
C.You cannot roll back to the same savepoint more than once.
D.Your last update fails to update any rows because employee ID 180 was already deleted. -
多项选择题
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2(30) JOB_ID NUMBER SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS table You created a sequence called EMP_ID_SEQ in order to populate sequential values for the EMPLOYEE_ID column of the EMPLOYEES table. Which two statements regarding the EMP_ID_SEQ sequence are true? （）
A.You cannot use the EMP_ID_SEQ sequence to populate the JOB_ID column.
B.The EMP_ID_SEQ sequence is invalidated when you modify the EMPLOYEE_ID column.
C.The EMP_ID_SEQ sequence is not affected by modifications to the EMPLOYEES table.
D.Any other column of NUMBER data type in your schema can use the EMP_ID_SEQ sequence.
E.The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEES table.
F.The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEE_ID column.
