你可能喜欢
多项选择题
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.
单项选择题
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
A. a schema object
B. a subquery that can contain an ORDER BY clause
C. another name for a view that contains group functions
D. a subquery that is part of the FROM clause of another query
单项选择题
A. no privileges
B. only the SELECT privilege
C. only the CONNECT privilege
D. all the privileges of a default user
多项选择题
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
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
单项选择题
A. creates a view with constraints
B. creates a view even if the underlying parent table has constraints
C. creates a view in another schema even if you don't have privileges
D. creates a view regardless of whether or not the base tables exist
单项选择题
A. WHERE lower(country_address) = "france"
B. WHERE lower(country_address) = 'france'
C. WHERE lower(country_address) IS 'france'
D. WHERE lower(country_address) = '%france%'
E. WHERE lower(country_address) LIKE %france%
单项选择题
A. You cannot update a view with group functions.
B. When you update a view group functions are automatically computed.
C. When you update a view only the constraints on the underlying table will be in effect.
D. When you update a view the constraints on the views always override the constraints on the underlying tables.
