单选题A SELECT statement can be used to perform these three functions: 1. Choose rows from a table. 2. Choose columns from a table 3. Bring together data that is stored in different tables by creating a link between them. Which set of keywords describes thes

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NBAR is a Cisco IOS feature that can be used to perform three tasks？

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A SELECT statement can be used to perform these three functions: 1. Choose rows from a table. 2. Choose columns from a table 3. Bring together data that is stored in different tables by creating a link between them. Which set of keywords describes these capabilities?（）

• A、difference, projection, join
• B、selection, projection, join
• C、selection, intersection, join
• D、intersection, projection, join
• E、difference, projection, product

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Evaluate the SQL statement:TRUNCATE TABLE DEPT;Which three are true about the SQL statement? （）

• A、It releases the storage space used by the table.
• B、It does not release the storage space used by the table.
• C、You can roll back the deletion of rows after the statement executes.
• D、You can NOT roll back the deletion of rows after the statement executes.
• E、An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
• F、You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table

第7题：

Where can subqueries be used?（）

• A、field names in the SELECT statement 
• B、the FROM clause in the SELECT statement 
• C、the HAVING clause in the SELECT statement
• D、the GROUP BY clause in the SELECT statement 
• E、the WHERE clause in only the SELECT statement 
• F、the WHERE clause in SELECT as well as all DML statements

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In which four clauses can a subquery be used?（）

• A、in the INTO clause of an INSERT statement
• B、in the FROM clause of a SELECT statement
• C、in the GROUP BY clause of a SELECT statement
• D、in the WHERE clause of a SELECT statement
• E、in the SET clause of an UPDATE statement
• F、in the VALUES clause of an INSERT statement

第16题：

Which NLS parameter can be used to change the default Oracle sort method from binary to linguistic for the SQL SELECT statement?（）

• A、NLS_LANG
• B、NLS_COMP
• C、NLS_SORT
• D、None of the above

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Which three are true?（）

• A、A MERGE statement is used to merge the data of one table with data from another.
• B、A MERGE statement replaces the data of one table with that of another.
• C、A MERGE statement can be used to insert new rows into a table.
• D、A MERGE statement can be used to update existing rows in a table.

第18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

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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.

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