Which of the following statements is correct? ( refer to the tables in the JustLee Books database). a. A PRIMARY KEY constraint allows NULL values in the primary key column(s). b. You can enable a dropped constraint if you need it in the future. c. Every table must have at least one PRIMARY KEY constraint, or Oracle 12 c doesn’t allow the table to be created. d. None of the above statements is correct

Which of the following statements is correct? ( refer to the tables in the JustLee Books database). a. A PRIMARY KEY constraint allows NULL values in the primary key column(s). b. You can enable a dropped constraint if you need it in the future. c. Every table must have at least one PRIMARY KEY constraint, or Oracle 12 c doesn’t allow the table to be created. d. None of the above statements is correct

Oracle 12c: SQL

3rd Edition

ISBN:9781305251038

Author:Joan Casteel

Publisher:Joan Casteel

Chapter4: Constraints

Section: Chapter Questions

Problem 1MC

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Similar questions

Which of the following statements is correct? (refer to the tables in the JustLee Books database) a. A table can contain a maximum of only one column marked as unused. b. You can delete a table by removing all columns in the table. c. Using the SET UNUSED clause allows you to free up storage space used by a column. d. None of the above statements are correct.
9. Write a trigger that prohibits duplicate values except for nulls in the NoDupName column of the following table: CREATE TABLE TestUniqueNulls (RowID NoDupName varchar(20) int IDENTITY NOT NULL, NULL); (Note that you can’t do this by using a unique constraint because the constraint wouldn’t allow duplicate null values.) If an INSERT or UPDATE statement creates a duplicate value, roll back the statement and return an error message. Write a series of INSERT statements that tests that duplicate null values are allowed but duplicates of other values are not.
Which of the following commands can you use to rename a constraint? ( refer to the tables in the JustLee Books database). a. RENAME b. ALTER CONSTRAINT c. MOVE d. NEW NAME e. None of the above commands can be used.
In the initial creation of a table, if a UNIQUE constraint is included for a composite column that requires the combination of entries in the specified columns to be unique, which of the following statements is correct? ( refer to the tables in the JustLee Books database). a. The constraint can be created only with the ALTER TABLE command. b. The constraint can be created only with the table-level approach. c. The constraint can be created only with the column-level approach. d. The constraint can be created only with the ALTER TABLE … MODIFY command
Which of the following is true? (refer to the tables in the JustLee Books database)a. If you truncate a table, you can’t 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 can’t 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, it’s always added as the last column of the table.
Create a table in your own database using the following statement. CREATE TABLE DateRange (DateID INT IDENTITY, DateValue DATE, DayOfWeek SMALLINT, Week SMALLINT, Month SMALLINT, Quarter SMALLINT, Year SMALLINT ); Write a stored procedure that accepts two parameters: A starting date The number of the consecutive dates beginning with the starting date The stored procedure then inserts data into all columns of the DateRange table according to the two provided parameters.
Which of the following statements is correct? (refer to the tables in the JustLee Books database.)a. The IN comparison operator can’t be used with a subquery that returns only one row of results.b. The equals (=) comparison operator can’t be used with a subquery that returns morethan one row of results.c. In an uncorrelated subquery, statements in the outer query are executed first, and thenstatements in the subquery are executed.d. A subquery can be nested only in the outer query’s SELECT clause.
Which of the following is a correct statement?a. If you attempt to add a record that violates a constraint for one of the table’s columns, only the valid columns for the row are added.b. A subquery nested in the VALUES clause of an INSERT INTO command can return only one value without generating an Oracle 12c error message.c. If you attempt to add a record that violates a NOT NULL constraint, a blank space is inserted automatically in the appropriate column so that Oracle 12c can complete the DML operation.d. None of the above statements is correct.
Write in SQL a command that creates the table Customers according to the above description. Write in SQL a statement that adds a new column named accountID of type Char(8). This column should be defined as a foreign key that relates the table Customers to the table Account . Write in SQL a command that deletes the customers whose date of birth is after 22-Dec-1990 .
Please written by computer source 1. For this project, you need to create the company database and populate it with the data given in the Oracle SQL PLUS environment (if you have not done so) 2. Your SQL commands should be placed in file(s) and run from the file(s). 3. Implement Triggers on all the tables to change character data to uppercase in the character data type columns. 4. Implement a Function that returns Dname from Department for any give employee. The parameter to the function would be the SSN. 5. Implement a Function that returns manager’s full name for any given department. The parameter to the function would be the department name. 6. Implement another Function that returns manager’s full name for any given department. The parameter to the function would be the department number. 7. Implement a Procedure that increases an employee salary by x%. Employee is identified by SSN and the percentage of increase is given as an input. 8. Implement a Package that contains the…
Which of the following is not a valid constraint type? ( refer to the tables in the JustLee Books database). a. PRIMARY KEYS b. UNIQUE c. CHECK d. FOREIGN KEY
Which of the following data dictionary objects should be used to view information about the constraints in a database? ( refer to the tables in the JustLee Books database). a. USER_TABLES b. USER_RULES c. USER_COLUMNS d. USER_CONSTRAINTS e. None of the above objects should be used