单项选择题
What is true of using group functions on columns that contain NULL values?（）
A. Group functions on columns ignore NULL values.
B. Group functions on columns returning dates include NULL values.
C. Group functions on columns returning numbers include NULL values.
D. Group functions on columns cannot be accurately used on columns that contain NULL values.
E. Group functions on columns include NULL values in calculations if you use the keyword INC_NULLS.
相关考题
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单项选择题
Which object privileges can be granted on a view? （）
A. none
B. DELETE, INSERT,SELECT
C. ALTER, DELETE, INSERT, SELECT
D. DELETE, INSERT, SELECT, UPDATE -
单项选择题
What is true about sequences? （）
A. Once created, a sequence belongs to a specific schema.
B. Once created, a sequence is linked to a specific table.
C. Once created, a sequence is automatically available to all users.
D. Only the DBA can control which sequence is used by a certain table.
E. Once created, a sequence is automatically used in all INSERT and UPDATE statements. -
单项选择题
The user Sue issues this SQL statement: GRANT SELECT ON sue. EMP TO alice WITH GRANT OPTION; The user Alice issues this SQL statement: GRANT SELECT ON sue. EMP TO reena WITH GRANT OPTION; The user Reena issues this SQL statement: GRANT SELECT ON sue. EMP TO timber; The user Sue issues this SQL statement: REVOKE select on sue. EMP FROM alice; For which users does the revoke command revoke SELECT privileges on the SUE.EMP table?（）
A. Alice only
B. Alice and Reena
C. Alice, Reena, and Timber
D. Sue, Alice, Reena, and Timber
