Which of the following describes the function of a common table expression? SELECT ONE OF THE FOLLOWING A. Operates similarly to a subquery, but depends on a reference from the outer query it is used in B. Operates similarly to a subquery, but is defined outside of the outer query it is used in C. Operates similarly to a subquery, but can only be used in the SELECT cause D. Operates similarly to a subquery, but can only be used in the WHERE cause

Which of the following describes the function of a common table expression? SELECT ONE OF THE FOLLOWING A. Operates similarly to a subquery, but depends on a reference from the outer query it is used in B. Operates similarly to a subquery, but is defined outside of the outer query it is used in C. Operates similarly to a subquery, but can only be used in the SELECT cause D. Operates similarly to a subquery, but can only be used in the WHERE cause

Oracle 12c: SQL

3rd Edition

ISBN:9781305251038

Author:Joan Casteel

Publisher:Joan Casteel

Chapter12: Subqueries And Merge Statements

Section: Chapter Questions

Problem 18MC

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Similar questions

Which of the following is the valid syntax for adding a PRIMARY KEY constraint to an existing table? ALTER TABLE tablename ADD CONSTRAINT PRIMARY KEY (columnname); ALTER TABLE tablename ADD CONSTRAINT (columnname) PRIMARY KEY constraintname; ALTER TABLE tablename ADD [CONSTRAINT constraintname] PRIMARY KEY; None of the above is valid syntax.
Which of the following is a correct statement? You can restore the data deleted with the DROP COLUMN clause, but not the data deleted with the SET UNUSED clause. You can’t create empty tables—all tables must contain at least three rows of data. A table can contain a maximum of 1000 columns. The maximum length of a table name is 265 characters.
Which of the following commands removes all data from a table but leaves the tables structure intact? a. ALTER TABLE secustomerorders DROP UNUSED COLUMNS; b. TRUNCATE TABLE secustomerorders; c. DELETE TABLE secustomerorders; d. DROP TABLE secustomerorders;
Which of the following is not a valid statement? You can change the name of a table only if it doesn’t contain any data. You can change the length of a column that doesn’t contain any data. You can delete a column that doesn’t contain any data. You can add a column to a table.
Which of the following is not a correct statement? A table can be modified only if it doesn’t contain any rows of data. The maximum number of characters in a table name is 30. You can add more than one column at a time to a table. You can’t recover data contained in a table that has been truncated.
A new table has been requested to support tracking automated emails sent to customers. Create the table and add data as described below. Tablename: email_log Columns: emailid (numeric), emaildate (datetime), customer# (numeric) Primary key: emailid column, define as an Identity Column Add the following data rows and display resulting rows (if any errors occur, explain why the error is expected) Emaildate = current date, customer# = 1007 Emailid = specify to use the column default value, emaildate = current date, customer# = 1008 Emailid = 25, emaildate = current date, customer# = 1009
Suppose you created a PRIMARY KEY constraint at the same time you created a table and later decide to name the constraint. Which of the following commands can you use to change the constraint’s name? ALTER TABLE … MODIFY ALTER TABLE … ADD ALTER TABLE … DISABLE None of the above commands can be used.
Which of the following is true? a. If you truncate a table, you cant add new data to the table. b. If you change the default value of an existing column, all existing rows containing a NULL value in the same column are set to the new DEFAULT value. c. If you delete a column from a table, you cant add a column to the table with the same name as the previously deleted column. d. If you add a column to an existing table, its always added as the last column of the table.
Which of the following is used to join data contained in two or more tables? a. primary key b. unique identifier c. common field d. foreign key
Add a constraint to make sure the Rep_ID value entered in the BOOK_STORES table is a valid value contained in the STORE_REPS table. The Rep_ID columns of both tables were initially created as different datatypes. Does this cause an error when adding the constraint? Make table modifications as needed so that you can add the required constraint.
When must a comma be used in the SELECT clause of a query? a. when a field name is followed by a column alias b. to separate the SELECT clause and the FROM clause when only one field is selected c. Its never used in the SELECT clause. d. when listing more than one field name and the fields arent concatenated e. when an arithmetic expression is included in the SELECT clause
Which of the following statements is correct? A table can contain a maximum of only one column marked as unused. You can delete a table by removing all columns in the table. Using the SET UNUSED clause allows you to free up storage space used by a column. None of the above statements are correct.