1. Selecting Rows from Tables Now that we know how to specify columns, how do we specify rows in a SELECT statement?

2. What we know so far SELECTING COLUMNS SELECTING COLUMNS ORDERING ROWS ORDERING ROWS SELECTING UNIQUE VALUES SELECTING UNIQUE VALUES

3. SELECTING COLUMNS SELECT * FROM table_name; SELECT * FROM table_name; –Select ALL columns SELECT column_name [, column_name …] FROM table_name; SELECT column_name [, column_name …] FROM table_name; –Select SOME columns

4. ORDERING ROWS SELECT * FROM table_name ORDER BY column_name [DESC] [, column_name [DESC]…]; SELECT * FROM table_name ORDER BY column_name [DESC] [, column_name [DESC]…]; SELECT column_name [, column_name …] FROM table_name ORDER BY column_number [DESC] [, column_number [DESC] …]; SELECT column_name [, column_name …] FROM table_name ORDER BY column_number [DESC] [, column_number [DESC] …];

5. SELECTING UNIQUE VALUES SELECT DISTINCT column_name FROM table_name SELECT DISTINCT column_name FROM table_name –Select unique values from a column SELECT COUNT(*) FROM table_name; SELECT COUNT(*) FROM table_name; –Count number of rows in a table.

6. ROWS Now that we can determine which COLUMNS appear in a query, and the ORDER of the ROWS, how do we specify WHICH ROWS appear? Now that we can determine which COLUMNS appear in a query, and the ORDER of the ROWS, how do we specify WHICH ROWS appear?

7. The ‘WHERE’ clause The ‘WHERE’ clause appears after the specification of the table name: The ‘WHERE’ clause appears after the specification of the table name: –SELECT column_specification FROM table_name where_clause [ORDER BY …]; The WHERE clause looks at EACH ROW to determine if it will be output. The WHERE clause looks at EACH ROW to determine if it will be output. The specified condition must evaluate to TRUE in order for the ROW to appear. The specified condition must evaluate to TRUE in order for the ROW to appear. Only the Columns specified for the Row are output. Only the Columns specified for the Row are output.

8. How to define the WHERE condition Compare columns to values: Compare columns to values: –WHERE column1 > 10 –WHERE Status = ‘VALID’ –WHERE NOT Name = ‘Smith’ Compare columns to one another Compare columns to one another –WHERE column1 > column2 –WHERE maxSalary = currentSalary

9. For more complicated conditions, use OR and AND. –WHERE LastName = ‘Smith’ AND FirstName = ‘James’ –WHERE LastName = ‘Smith’ OR LastName = ‘Bernardo’

10. To USE more than one AND or OR: Use Parentheses Use Parentheses –WHERE FirstName = ‘James’ AND ( LastName = ‘Monroe’ OR LastName = ‘Madison’ )

11. Putting it all together 1. Decide on the columns (and order of columns) you will output. SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification; SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification; 2. Determine the condition for including rows. SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification; SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification; 3. Specify the order of the included rows. SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification; SELECT column_specification FROM table_name WHERE where_condition ORDER BY order_specification;

12. Exercises Use this table, which we will call “Electives” Use this table, which we will call “Electives” CourseNameTeacherRoomNumberMeetingTimesSeatsLeft 3d Art IIMalik516T2-F314 AstronomySignorelli522T4-R411 BotanyR. Dinallo522T6-R61 Digital DesignA. Dinallo320M9-R90

13. Exercise 1 Select all records from the table where there are seats left. SELECT * FROM Electives WHERE __________; WHERE __________;

14. Exercise 2 Select all records where there are seats left, and the room is either 516 or 522. SELECT * FROM Electives WHERE ________

15. Exercise 3 Select the room numbers and meeting times of courses that are not full (have seats left) SELECT _________ FROM Electives WHERE ___________________ WHERE ___________________

16. Exercise 4 Select the coursenames that either ‘Dinallo’ teaches and order them by room number. SELECT coursename FROM Electives WHERE _______________ WHERE _______________ ORDER BY ______________ ORDER BY ______________

17. Exercise 5 Select the courses and seats left that are not on the ‘third’ floor (e.g. room is not 300-399) ordered by number of seats left, with the most seats left listed first. Select the courses and seats left that are not on the ‘third’ floor (e.g. room is not 300-399) ordered by number of seats left, with the most seats left listed first.