Answer:
View Base tables: Virtual table based on a SELECT query
CREATE VIEW statement: Data definition command that stores the query specification in the data dictionary
DROP VIEW statement: Data definition command that removes the query specification in the data dictionary
Explanation:
Views are virtual tables, which can be created by select queries using the real database tables.
Creating and dropping views can be done by the CREATE VIEW and DROP VIEW statements.
<u>CREATE VIEW syntax:</u>
CREATE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;
<u>DROP VIEW syntax:</u>
DROP VIEW view_name;
Answer:
The Date class below is created using Java.
- public class Date {
- private int day;
- private int month;
- private int year;
- public Date(int d, int m, int y)
- {
- setDay(d);
- setMonth(m);
- this.year = y;
- }
- public void setMonth(int m)
- {
- if(m >= 1 && m <= 12)
- {
- this.month = m;
- }
- else
- {
- throw new IllegalArgumentException("Input Month must be between 1 - 12");
- }
- }
- public void setDay(int d)
- {
- if(d >=1 && d <=31)
- {
- this.day = d;
- }
- else
- {
- throw new IllegalArgumentException("Input Day must be between 1 - 31");
- }
- }
- public void printDate()
- {
- System.out.println(this.month + "/" + this.day + "/" + this.year);
- }
- }
Explanation:
Line 1:
- Create a class and name it as <em>Date</em>
Line 3-5:
- Define three properties/attributes in the Date class which are day, month and year.
- The data type of the properties are defined as integer
Line 7-13:
- Create a class constructor to initialize the values for the properties (day, month and year).
- To initialize the day and month, setDay() and setMonth() setter methods are called. This is to ensure the day and month are within the range of 1-31 and 1-12, respectively.
Line 15-25:
- Create setMonth() setter method with one parameter m to accept one input value.
- The setMonth() method will check the input value m to see if it is bigger or equal to 1 and less than or equal to 31 (the valid range). If not, an error will be thrown.
Line 27 - 37:
- Create setDay() setter method with one parameter d to accept one input value.
- The setDay() method will check the input value m to see if it is bigger or equal to 1 and less than or equal to 12 (the valid range). If not, an error will be thrown.
Line 39 - 42:
- Create printDate() method to display the date as month/day/year (ie 10/1/1999)
- Use Java println() method to print the class property values, month, day, and year.
- Please note that to access the property values, this keyword must be preceded with the property name.
Important notes:
- This program doesn't consider the valid input range of days for Feb (1 - 28 or 29) and for those of the months with only 30 days because this is not expected by the question.
- Beside, the input year is also presumed to be a four digit number.
It stands for VESA Local Bus
Answer:
Mobile
Explanation:
They completely discontinued it before they started being deficit