多项选择题

In which two cases would you use an outer join? （）

A. The tables being joined have NOT NULL columns.
B. The tables being joined have only matched data.
C. The columns being joined have NULL values.
D. The tables being joined have only unmatched data.
E. The tables being joined have both matched and unmatched data.
F. Only when the tables have a primary key/foreign key relationship.

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热门试题

单项选择题The PRODUCTS table has these columns: PRODUCT_ID NUMBER(4) PRODUCT_NAME VARCHAR2(45) PRICE NUMBER(8,2) Evaluate this SQL statement: SELECT * FROM PRODUCTS ORDER BY price, product _ name; What is true about the SQL statement? （）

A. The results are not sorted.
B. The results are sorted numerically.
C. The results are sorted alphabetically.
D. The results are sorted numerically and then alphabetically.

单项选择题Which best describes an inline view? （）

A. a schema object
B. a subquery that can contain an ORDER BY clause
C. another name for a view that contains group functions
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单项选择题The DBA issues this SQL command: CREATE USER scott IDENTIFIED by tiger; What privileges does the user Scott have at this point?（）

A. no privileges
B. only the SELECT privilege
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A. convert 10 to 'TEN'
B. convert '10' to 10
C. convert 10 to '10'
D. convert 'TEN' to 10
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F. convert a character expression to a date

单项选择题A data manipulation language statement （）.

A. completes a transaction on a table
B. modifies the structure and data in a table
C. modifies the data but not the structure of a table
D. modifies the structure but not the data of a table