单项选择题
A subquery can be used to（）.
A.create groups of data
B.sort data in a specific order
C.convert data to a different format
D.retrieve data based on an unknown condition
相关考题
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单项选择题
Mary has a view called EMP_DEPT_LOC_VU that was created based on the EMPLOYEES, DEPARTMENTS, and LOCATIONS tables. She granted SELECT privilege to Scott on this view. Which option enables Scott to eliminate the need to qualify the view with the name MARY.EMP_DEPT_LOC_VU each time the view is referenced?（）
A.Scott can create a synonym for the EMP_DEPT_LOC_VU by using the command CREATE PRIVATE SYNONYM EDL_VU FOR mary.EMP_DEPT_LOC_VU; then he can prefix the columns with this synonym.
B.Scott can create a synonym for the EMP_DEPT_LOC_VU by using the command CREATE SYNONYM EDL_VU FOR mary.EMP_DEPT_LOC_VU; then he can prefix the columns with this synonym.
C.Scott can create a synonym for the EMP_DEPT_LOC_VU by using the command CREATE LOCAL SYNONYM EDL_VU FOR mary.EMP_DEPT_LOC_VU; then he can prefix the columns with this synonym.
D.Scott can create a synonym for the EMP_DEPT_LOC_VU by using the command CREATE SYNONYM EDL_VU ON mary(EMP_DEPT_LOC_VU); then he can prefix the columns with this synonym.
E.Scott cannot create a synonym because synonyms can be created only for tables.
F.Scott cannot create any synonym for Mary's view. Mary should create a private synonym for the view and grant SELECT privilege on that synonym to Scott. -
单项选择题
The EMP table contains these columns: EMPLOYEE_ID NUMBER(4) EMPNAME VARCHAR2 (25) SALARY NUMBER(9,2) HIRE_DATE DATE You query the database with this SQL statement: SELECT empname,hire_date HIREDATE, salary FROM EMP ORDER BY hire_date; How will the results be sorted?（）
A.randomly
B.ascending by date
C.descending by date
D.ascending alphabetically
E.descending alphabetically -
多项选择题
Evaluate the SQL statement: TRUNCATE TABLE DEPT;Which three are true about the SQL statement? （）
A.It releases the storage space used by the table.
B.It does not release the storage space used by the table.
C.You can roll back the deletion of rows after the statement executes.
D.You can NOT roll back the deletion of rows after the statement executes.
E.An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F.You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table.
