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 retrie

题目

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.
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.A general purpose MySQL instance is configured with the following options:—log-slow-queries—long-query-time=,0001—log-slow-admin-queries—general-log—log-bin—binlog-format=STATEMENT—innodb-flush-log-at-trx-commit=1Which three statements are true（）。A.The General Query Log records more data than the Binary LogB.The binary Log records more data than the General Query LogC.The Slow Query Log records more data than the General Query LogD.The General Query Log records more data than the Slow Query LogE.The Slow Query Log records more data than the Binary LogF.The Binary Log records more data than the Slow Query Log

3.Examine the data from the ORDERS and CUSTOMERS tables.Evaluate the SQL statement:What is the result when the query is executed?()A.B.C.D. The query fails because the subquery returns more than one row.E. The query fails because the outer query and the inner query are using different tables.

4.You define a multiple－row subquery in the WHERE clause of an SQL query with a comparison operator "=". What happens when the main query is executed? ()A. The main query executes with the first value returned by the subquery.B. The main query executes with the last value returned by the subquery.C. The main query executes with all the values returned by the subquery.D. The main query fails because the multiple-row subquery cannot be used with the comparison operator.E. You cannot define a multiple-row subquery in the WHERE clause of a SQL query.

更多“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 retrie”相关问题

  • 第1题：

    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：A

  • 第2题：

    Which of the following statements about a Sales Catalog is TRUE？（）

    • A、A store can only have one sales catalog.
    • B、A sales catalog is used to bundle similar products.
    • C、A sales catalog may be used to place a product in more than one category.
    • D、Every store must have a sales catalog.

    正确答案:C

  • 第3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:C,D

  • 第4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5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6题：

    You define a multiple-row subquery in the WHERE clause of an SQL query with a comparison operator "=". What happens when the main query is executed? （）

    • A、The main query executes with the first value returned by the subquery.
    • B、The main query executes with the last value returned by the subquery.
    • C、The main query executes with all the values returned by the subquery.
    • D、The main query fails because the multiple-row subquery cannot be used with the comparison operator.
    • E、You cannot define a multiple-row subquery in the WHERE clause of a SQL query.

    正确答案:D

  • 第7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8题：

    Which two statements are true about simple views？（）

    • A、Views can be created as read only.
    • B、Views are data segments like tables.
    • C、Views can be created on the basis of more than one table.
    • D、Data manipulation language （DML） operations cannot be performed on views.

    正确答案:A,C

  • 第9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10题：

    多选题
    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： C,D
    解析： 暂无解析

  • 第11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12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

  • 第13题：

    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.


    参考答案：A

  • 第14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:A,B,E

  • 第15题：

    A general purpose MySQL instance is configured with the following options: —log-slow-queries —long-query-time=,0001 —log-slow-admin-queries —general-log —log-bin —binlog-format=STATEMENT —innodb-flush-log-at-trx-commit=1 Which three statements are true（）。

    • A、The General Query Log records more data than the Binary Log
    • B、The binary Log records more data than the General Query Log
    • C、The Slow Query Log records more data than the General Query Log
    • D、The General Query Log records more data than the Slow Query Log
    • E、The Slow Query Log records more data than the Binary Log
    • F、The Binary Log records more data than the Slow Query Log

    正确答案:A,D,E

  • 第16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17题：

    Which two statements are true regarding the WebLogic domain?（）

    • A、A WebLogic domain can have more than one Administration server.
    • B、A WebLogic domain has at least one WebLogic server.
    • C、A WebLogic domain can have at the most one cluster.  
    • D、A WebLogic domain can cross multiple physical machines.  
    • E、Each WebLogic domain is associated with a different Node Manager.

    正确答案:B,D

  • 第18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19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20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21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22题：

    单选题
    Which of the following statements about a Sales Catalog is TRUE？（）
    A

    A store can only have one sales catalog.

    B

    A sales catalog is used to bundle similar products.

    C

    A sales catalog may be used to place a product in more than one category.

    D

    Every store must have a sales catalog.


    正确答案： A
    解析： 暂无解析

  • 第23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24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

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