Oracle 12c: SQL
3rd Edition
ISBN: 9781305251038
Author: Joan Casteel
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Expert Solution & Answer
Chapter 4, Problem 10RQ
Explanation of Solution
Determining NULL values
- The NULL value is used to represent a missing value.
- A NULL value in a table is a value in a field that appears to be blank...
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A Pivot Table is the column name with its table name.
O True
O False
What prevents a column from having a NULL value?
There are ten columns in the table "customer," yet there is no row. A total of 10 new rows are added to the table, while 3 old ones are removed. What is the table 'customer's' degree and cardinality?
Chapter 4 Solutions
Oracle 12c: SQL
Ch. 4 - What is the difference between a PRIMARY KEY...Ch. 4 - How can you verify the constraints that exist for...Ch. 4 - A table can have a maximum of how many PRIMARY KEY...Ch. 4 - Which type of constraint can be used to make...Ch. 4 - Which type of constraint should you use to ensure...Ch. 4 - How is adding a NOT NULL constraint to an existing...Ch. 4 - When must you define constraints at the table...Ch. 4 - Prob. 8RQCh. 4 - What is the difference between disabling a...Ch. 4 - Prob. 10RQ
Ch. 4 - Prob. 1MCCh. 4 - Which of the following is not a valid constraint...Ch. 4 - Which of the following SQL statements is invalid...Ch. 4 - What is the maximum number of PRIMARY KEY...Ch. 4 - Prob. 5MCCh. 4 - How many NOT NULL constraints can be created at...Ch. 4 - The FOREIGN KEY constraint should be added to...Ch. 4 - What is the maximum number of columns you can...Ch. 4 - Which of the following commands can you use to...Ch. 4 - Prob. 10MCCh. 4 - In the initial creation of a table, if a UNIQUE...Ch. 4 - Which type of constraint should you use on a...Ch. 4 - Which of the following commands can be used to...Ch. 4 - Which of the following keywords allows the user to...Ch. 4 - Which of the following data dictionary objects...Ch. 4 - Which of the following types of constraints cant...Ch. 4 - Suppose you created a PRIMARY KEY constraint at...Ch. 4 - You’re creating a new table consisting of three...Ch. 4 - Which of the following types of restrictions can...Ch. 4 - Which of the following is the valid syntax for...Ch. 4 - Prob. 1HOACh. 4 - Prob. 2HOACh. 4 - Prob. 3HOACh. 4 - Add a column named Base_salary with a datatype of...Ch. 4 - Create a table named BOOK_STORES to include the...Ch. 4 - Add a constraint to make sure the Rep_ID value...Ch. 4 - Change the constraint created in Assignment #6 so...Ch. 4 - Create a table named REP_CONTRACTS containing the...Ch. 4 - Produce a list of information about all existing...Ch. 4 - Issue the commands to disable and then enable the...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
- What happens if you try to decrease the scale or precision of a NUMBER column to a value less than the data already stored in the field?arrow_forwardHow do we avoid getting duplicate entries in a query?arrow_forwardEnsure that the only legal values for the BDRMS column in the CONDO_UNIT table are 1, 2, or 3.arrow_forward
- What is the maximum number of columns you can define as a primary key when using the column-level approach to creating a table? a. 0 b. 1 c. 30 d. 255arrow_forwardEnsure that the only legal values for the TYPE column in the TRIP table are Biking, Hiking, or Paddling.arrow_forwardAdd two columns to the EMPLOYEES table. One column, named EmpDate, contains the date of employment for each employee, and its default value should be the system date. The second column, named EndDate, contains employees date of termination.arrow_forward
- 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# = 1009arrow_forwardIf a column has low selectivity, this means:a. The column contains many distinct values.b. The column contains a small number of distinct values.c. A WHERE clause is always used in a query on the column.d. The selectivity of a column can’t be determinedarrow_forwardWhat SQL statement function is used to generate a column, where the value for the new column is dependant on another column's value for the row of data (i.e SQL IF statement)?arrow_forward
- In order to prevent the duplicate values to be inserted to a column of a table, we use the DISTINCT keyword when creating the table. True Falsearrow_forwardSQL optimizer tries to convert queries with nested subqueries into a join operation for better performance True Falsearrow_forwardorder db orderid int custid int itemcode int orderquantity int deliverydate date modeofpayment char(1) date_of_order datearrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
A Guide to SQLComputer ScienceISBN:9781111527273Author:Philip J. PrattPublisher:Course Technology Ptr- Np Ms Office 365/Excel 2016 I NtermedComputer ScienceISBN:9781337508841Author:CareyPublisher:Cengage
Database Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781305627482Author:Carlos Coronel, Steven MorrisPublisher:Cengage Learning
A Guide to SQL
Computer Science
ISBN:9781111527273
Author:Philip J. Pratt
Publisher:Course Technology Ptr
Np Ms Office 365/Excel 2016 I Ntermed
Computer Science
ISBN:9781337508841
Author:Carey
Publisher:Cengage
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781305627482
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning