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Which two statements are true regarding views?（）A、A subquery that defines a view cannot include the GROUP BY clause B、A view that is created with the subquery having the DISTINCT keyword can be updated C、A view that is created with the subquery having the

题目

Which two statements are true regarding views?（）

  • A、A subquery that defines a view cannot include the GROUP BY clause 
  • B、A view that is created with the subquery having the DISTINCT keyword can be updated 
  • C、A view that is created with the subquery having the pseudo column ROWNUM keyword cannot be updated 
  • D、A data manipulation language (DML) operation can be performed on a view that is created with the subquery having all the NOT NULL columns of a table
相似考题

1.Which best describes an inline view? ()A. a schema objectB. a subquery that can contain an ORDER BY clauseC. another name for a view that contains group functionsD. a subquery that is part of the FROM clause of another query

2.Click the Exhibit button and examine the data in the EMPLOYEES table.Examine the subquery:SELECT last_nameFROM employeesWHERE salary IN (SELECT MAX(salary)FROM employeesGROUP BY department_id);Which statement is true?（）A.The SELECT statement is syntactically accurate.B.The SELECT statement does not work because there is no HAVING clause.C.The SELECT statement does not work because the column specified in the GROUP BY clause is not in the SELECT list.D.The SELECT statement does not work because the GROUP BY clause should be in the main query and not in the subquery.

3.Which three statements are true regarding subqueries?（）A、Subqueries can contain GROUP BY and ORDER BY clauses B、Main query and subquery can get data from different tables C、Main query and subquery must get data from the same tables D、Subqueries can contain ORDER BY but not the GROUP BY clause E、Only one column or expression can be compared between the main query and subqueryF、 Multiple columns or expressions can be compared between the main query and subquery

4.Exhibit:Examine the data in the EMPLOYEES table.Examine the subquery:SELECT last_nameFROM employeesWHERE salary IN (SELECT MAX(salary)FROM employeesGROUP BY department_id);Which statement is true?()A. The SELECT statement is syntactically accurate.B. The SELECT statement does not work because there is no HAVING clause.C. The SELECT statement does not work because the column specified in the GROUP BY clause is not in the SELECT list.D. The SELECT statement does not work because the GROUP BY clause should be in the main query and not in the subquery.

参考答案和解析
正确答案:C,D
更多“Which two statements are true regarding views?（）A、A subquery that defines a view cannot include the GROUP BY clause B、A view that is created with the subquery having the DISTINCT keyword can be updated C、A view that is created with the subquery having the”相关问题

  • 第1题：

    Which two statements are true about WHERE and HAVING clauses? （）

    • A、A WHERE clause can be used to restrict both rows and groups.
    • B、A WHERE clause can be used to restrict rows only.
    • C、A HAVING clause can be used to restrict both rows and groups.
    • D、A HAVING clause can be used to restrict groups only.
    • E、A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.
    • F、A HAVING clause CANNOT be used in subqueries.

    正确答案:B,D

  • 第2题：

    Which three statements about subqueries are true? （）

    • A、A main query can have more than one subquery.
    • B、A subquery can have more than one main query.
    • C、The subquery and main query must retrieve data from the same table.
    • D、The subquery and main query can retrieve data from different tables.
    • E、Only one column or expression can be compared between the subquery and main query.
    • F、Multiple columns or expression can be compared between the subquery and main query.

    正确答案:A,C,E

  • 第3题：

    Which two statements are true regarding the ORDER BY clause? （）

    • A、It is executed first in the query execution 
    • B、It must be the last clause in the SELECT statement 
    • C、It cannot be used in a SELECT statement containing a HAVING clause
    • D、You cannot specify a column name followed by an expression in this clause 
    • E、You can specify a combination of numeric positions and column names in this clause

    正确答案:B,E

  • 第4题：

    Which two statements about subqueries are true?（）

    • A、A single row subquery can retrieve data from only one table.
    • B、A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.
    • C、A SQL query statement can display data from table B that is referred to in its subquery, without including table B in its own FROM clause.
    • D、A single row subquery can retrieve data from more than one table.
    • E、A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.
    • F、A multiple-row subquery cannot be used in a condition where the LIKE operator is used for comparison.

    正确答案:B,D

  • 第5题：

    Which two statements about views are true?（）

    • A、A view can be created as read only.
    • B、A view can be created as a join on two or more tables.
    • C、A view cannot have an ORDER BY clause in the SELECT statement.
    • D、A view cannot be created with a GROUP BY clause in the SELECT statement.
    • E、A view must have aliases defined for the column names in the SELECT statement.

    正确答案:A,B

  • 第6题：

    Which two statements about creating constraints are true?（）

    • A、Constraint names must start with SYS_C
    • B、All constraints must be defines at the column level.
    • C、Constraints can be created after the table is created.
    • D、Constraints can be created at the same time the table is created.
    • E、Information about constraints is found in the VIEW_CONSTRAINTS dictionary view.

    正确答案:C,D

  • 第7题：

    多选题
    Which three statements about subqueries are true?（）
    A

    A single row subquery can retrieve only one column and one row.

    B

    A single row subquery can retrieve only one row but many columns.

    C

    A multiple row subquery can retrieve multiple rows and multiple columns.

    D

    A multiple row subquery can be compared by using the “>” operator.

    E

    A single row subquery can use the IN operator.

    F

    A multiple row subquery can use the “=” operator.


    正确答案： A,D
    解析： 暂无解析

  • 第8题：

    多选题
    Which two statements about views are true?（）
    A

    A view can be created as read only.

    B

    A view can be created as a join on two or more tables.

    C

    A view cannot have an ORDER BY clause in the SELECT statement.

    D

    A view cannot be created with a GROUP BY clause in the SELECT statement.

    E

    A view must have aliases defined for the column names in the SELECT statement.


    正确答案： D,E
    解析： 暂无解析

  • 第9题：

    多选题
    Which two statements about creating constraints are true?（）
    A

    Constraint names must start with SYS_C

    B

    All constraints must be defines at the column level

    C

    Constraints can be created after the table is created

    D

    Constraints can be created at the same time the table is created

    E

    Information about constraints is found in the VIEW_CONSTRAINTS dictionary view


    正确答案： C,D
    解析： 暂无解析

  • 第10题：

    多选题
    Which two statements about subqueries are true? （）
    A

    A single row subquery can retrieve data from only one table.

    B

    A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.

    C

    A SQL query statement can display data from table B that is referred to in its subquery, without including B in its own FROM clause.

    D

    A single row subquery can retrieve data from more than one table.

    E

    A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.

    F

    A multiple-row subquery cannot be used in an INSERT statement to insert multiple rows at a time.


    正确答案： A,F
    解析： 暂无解析

  • 第11题：

    多选题
    Which two statements are true regarding views?（）
    A

    A subquery that defines a view cannot include the GROUP BY clause

    B

    A view that is created with the subquery having the DISTINCT keyword can be updated

    C

    A view that is created with the subquery having the pseudo column ROWNUM keyword cannot be updated

    D

    A data manipulation language (DML) operation can be performed on a view that is created with the subquery having all the NOT NULL columns of a table


    正确答案： D,B
    解析： 暂无解析

  • 第12题：

    单选题
    Exhibit: Examine the data in the EMPLOYEES table. Examine the subquery: SELECT last_name FROM employees WHERE salary IN (SELECT MAX(salary) FROM employees GROUP BY department_id); Which statement is true?（）
    A

    The SELECT statement is syntactically accurate.

    B

    The SELECT statement does not work because there is no HAVING clause.

    C

    The SELECT statement does not work because the column specified in the GROUP BY clause is not in the SELECT list.

    D

    The SELECT statement does not work because the GROUP BY clause should be in the main query and not in the subquery.


    正确答案： C
    解析： 暂无解析

  • 第13题：

    Which two statements about subqueries are true? （）

    • A、A subquery should retrieve only one row.
    • B、A subquery can retrieve zero or more rows.
    • C、A subquery can be used only in SQL query statements.
    • D、Subqueries CANNOT be nested by more than two levels.
    • E、A subquery CANNOT be used in an SQL query statement that uses group functions.
    • F、When a subquery is used with an inequality comparison operator in the outer SQL statement, the column list in the SELECT clause of the subquery should contain only one column.

    正确答案:B,F

  • 第14题：

    Which three statements about subqueries are true?（）

    • A、A single row subquery can retrieve only one column and one row.
    • B、A single row subquery can retrieve only one row but many columns.
    • C、A multiple row subquery can retrieve multiple rows and multiple columns.
    • D、A multiple row subquery can be compared by using the ">" operator.
    • E、A single row subquery can use the IN operator.
    • F、A multiple row subquery can use the "=" operator.

    正确答案:B,C,D

  • 第15题：

    Which two statements are true regarding subqueries? （）

    • A、A subquery can retrieve zero or more rows 
    • B、Only two subqueries can be placed atone level 
    • C、A subquery can be used only in SQL query statements 
    • D、A subquery can appear on either side of a comparison operator 
    • E、There is no limit on the number of subquery levels in the WHERE clause of a SELECT statement 

    正确答案:A,D

  • 第16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
    • D、a subquery that is part of the FROM clause of another query

    正确答案:D

  • 第17题：

    Which two statements about creating constraints are true? （）

    • A、Constraint names must start with SYS_C
    • B、All constraints must be defines at the column level
    • C、Constraints can be created after the table is created
    • D、Constraints can be created at the same time the table is created
    • E、Information about constraints is found in the VIEW_CONSTRAINTS dictionary view

    正确答案:C,D

  • 第18题：

    单选题
    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

    D

    a subquery that is part of the FROM clause of another query


    正确答案： B
    解析： 暂无解析

  • 第19题：

    多选题
    Which two statements are true regarding subqueries? （）
    A

    A subquery can retrieve zero or more rows

    B

    Only two subqueries can be placed atone level

    C

    A subquery can be used only in SQL query statements

    D

    A subquery can appear on either side of a comparison operator

    E

    There is no limit on the number of subquery levels in the WHERE clause of a SELECT statement


    正确答案： E,B
    解析： 暂无解析

  • 第20题：

    多选题
    Which two statements are true about WHERE and HAVING clauses? （）
    A

    A WHERE clause can be used to restrict both rows and groups.

    B

    A WHERE clause can be used to restrict rows only.

    C

    A HAVING clause can be used to restrict both rows and groups.

    D

    A HAVING clause can be used to restrict groups only.

    E

    A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.

    F

    A HAVING clause CANNOT be used in subqueries.


    正确答案： B,D
    解析： 暂无解析

  • 第21题：

    多选题
    Which two statements about creating constraints are true?（）
    A

    Constraint names must start with SYS_C

    B

    All constraints must be defines at the column level.

    C

    Constraints can be created after the table is created.

    D

    Constraints can be created at the same time the table is created.

    E

    Information about constraints is found in the VIEW_CONSTRAINTS dictionary view.


    正确答案： A,E
    解析： 暂无解析

  • 第22题：

    多选题
    Which two statements about subqueries are true? （）
    A

    A subquery should retrieve only one row.

    B

    A subquery can retrieve zero or more rows.

    C

    A subquery can be used only in SQL query statements.

    D

    Subqueries CANNOT be nested by more than two levels.

    E

    A subquery CANNOT be used in an SQL query statement that uses group functions.

    F

    When a subquery is used with an inequality comparison operator in the outer SQL statement, the column list in the SELECT clause of the subquery should contain only one column.


    正确答案： C,D
    解析： 暂无解析

  • 第23题：

    多选题
    Which three statements are true regarding subqueries?（）
    A

    Subqueries can contain GROUP BY and ORDER BY clauses

    B

    Main query and subquery can get data from different tables

    C

    Main query and subquery must get data from the same tables

    D

    Subqueries can contain ORDER BY but not the GROUP BY clause

    E

    Only one column or expression can be compared between the main query and subquery

    F

    Multiple columns or expressions can be compared between the main query and subquery


    正确答案： B,D
    解析： 暂无解析

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