单项选择题
Evaluate this SQL statement:
SELECT e.EMPLOYEE_ID,e.LAST_NAME,e.DEPARTMENT_ID, d.DEPARTMENT_NAME
FROM EMPLOYEES e, DEPARTMENTS d
WHERE e.DEPARTMENT_ID = d.DEPARTMENT_ID;
In the statement, which capabilities of a SELECT statement are performed?（）
A.selection, projection, join
B.difference, projection, join
C.selection, intersection, join
D.intersection, projection, join
E.difference, projection, product
相关考题
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单项选择题
Click the Exhibit button and examine the data from the ORDERS and CUSTOMERS tables. Evaluate this SQL statement: SELECT cust_id, ord_total FROM orders WHERE ord_total > ANY(SELECT ord_total FROM orders WHERE cust_id IN (SELECT cust_id FROM customers WHERE city LIKENew York)); What is the result when the above query is executed?（）
A.A
B.B
C.C
D.D
E.E -
单项选择题
Examine the structure of the EMP_DEPT_VU view: Column Name Type Remarks EMPLOYEE_ID NUMBER From the EMPLOYEES table EMP_NAME VARCHAR2(30) From the EMPLOYEES table JOB_ID VARCHAR2(20) From the EMPLOYEES table SALARY NUMBER From the EMPLOYEES table DEPARTMENT_ID NUMBER From the DEPARTMENTS table DEPT_NAME VARCHAR2(30) From the DEPARTMENTS table Which SQL statement produces an error?（）
A.SELECT*FROMemp_dept_vu；
B.SELECTdepartment_id，SUM（salary）FROMemp_dept_vuGROUPBYdepartment_id；
C.SELECTdepartment_id，job_id，AVG（salary）FROMemp_dept_vuGROUPBYdepartment_id，job_id；
D.SELECTjob_id，SUM（salary）FROMemp_dept_vuWHEREdepartment_idIN（10，20）GROUPBYjob_idHAVINGSUM（salary）>；20000；
E.Noneofthestatementsproduceanerror；allarevalid -
多项选择题
Examine the SQL statement that creates ORDERS table: CREATE TABLE orders (SER_NO NUMBER UNIQUE, ORDER_ID NUMBER, ORDER_DATE DATE NOT NULL, STATUS VARCHAR2(10) CHECK (status IN (CREDIT, CASH)), PROD_ID NUMBER REFERENCES PRODUCTS(PRODUCT_ID), ORD_TOTAL NUMBER, PRIMARY KEY (order_id, order_date)); For which columns would an index be automatically created when you execute the above SQL statement? （）
A.SER_NO
B.ORDER_ID
C.STATUS
D.PROD_ID
E.ORD_TOTAL
F.composite index on ORDER_ID and ORDER_DATE
