How to create datatype for columns in tables and key constraints. To learn about creating table, insert, select, update and deleting records in table

1. Unit 2
Introduction to MySQL

2. Naming Database Elements
Rules:
• Letters, numbers, underscore
• No keywords
• Case-sensitive
• <=64 characters
• unique

3. To name a database element:
• Determine database’s name
• Determine table’s name
• Determine the column names inside the table.

4. Choose the column type
• Text, number, date/time type
• Most appropriate type
• Set maximum length

6. • Char
• Varchar

7. Column Properties
• Index
• Key
• 2 types of keys: primary & foreign
• 3 rules:
Must have a value
Never change
Unique

8. Key Constraint
• Auto increment
• Not null
• Default
• Timestamp
• Enum
• Unsigned
• Zerofill

9. Rules for defining column
• Identify primary key
• Identify column-not null
• Identify column-unsigned
• Default value
• Confirm final column definition

10. Accessing MySQL
• Client applications: mysql client & phpMyAdmin
• Mysql client:
Command-line prompt
To start: type ‘mysql’
Xampp-C:xamppmysqlbinmysql
Mamp-/Applications/MAMP/Library/bin/mysql
To establish the connection: mysql -u username -h hostname –p
Steps to use mysql client: access, invoke, enter password, select DB, quit
mysql, quit terminal.

11. Accessing MySQL
• phpMyAdmin:
Best and most popular
Easy to use
Access: http://localhost/phpMyAdmin
Steps: access, select DB, select table, perform task, execute SQL commands

12. Introduction to SQL

13. Creating Database and Tables
• To create Database:
CREATE DATABASE databasename;
Eg: CREATE DATABASE sitename;
USE sitename;
• To create table:
CREATE TABLE tablename (
column1name description,
column2name description
…);

14. Creating table
• Eg:
CREATE TABLE users (
user_id MEDIUMINT UNSIGNED NOT NULL
AUTO_INCREMENT,
first_name VARCHAR(20) NOT NULL,
last_name VARCHAR(40) NOT NULL,
email VARCHAR(60) NOT NULL,
pass CHAR(40) NOT NULL,
registration_date DATETIME NOT NULL,
PRIMARY KEY (user_id)
);

15. Viewing table
• SHOW TABLES;
• SHOW COLUMNS FROM tablename;
(or)
DESCRIBE tablename;

16. Viewing table

17. Inserting record
Two methods:
• INSERT INTO tablename (column1, column2…) VALUES (value1,
value2 …);
INSERT INTO tablename (column4, column8) VALUES (valueX, valueY);
• INSERT INTO tablename VALUES (value1, NULL, value2, value3, …);
• Insert multiple row at a time:
INSERT INTO tablename (column1, column4) VALUES (valueA, valueB),
(valueC, valueD),(valueE, valueF);

18. Example
• INSERT INTO users (first _ name, last _ name, email, pass,
registration_date) VALUES ('Larry', 'Ullman', 'email@example.com’,
SHA1('mypass’), NOW( ));

19. Two MySQL functions
• SHA1()
to encrypt data.
• NOW()
return current date and time.

20. Rules
• Numeric value shouldn’t be quoted.
• String values must always be quoted.
• Date and time values must always be quoted.
• Functions cannot be quoted.
• The word NULL must not be quoted.

21. Selecting data
• Syntax: SELECT which_columns FROM which_table;
• SELECT * FROM tablename;
• SELECT column1, column3 FROM tablename;
• SELECT NOW();
• Can select the order & can display multiple times.

22. Example

23. Example

24. Using Conditionals
Syntax: SELECT which_columns FROM which_table WHERE condition(s);
Example:
• SELECT name FROM people WHERE birth_date = '2011-01-26’;
• SELECT * FROM items WHERE (price BETWEEN 10.00 AND 20.00) AND
(quantity > 0)
SELECT * FROM cities WHERE (zip _code = 90210) OR (zip _code =90211);
• SELECT * FROM cities WHERE zip_code IN (90210, 90211)

25. MySQL Operators

26. Example

27. Example

28. Example
SELECT first_name, last_name FROM
users WHERE user_id
NOT BETWEEN 10 and 20;
SELECT first_name, last_name FROM
users WHERE user_id NOT IN
(10, 11, 12, 13, 14, 15, 16, 17, 18,
➝19, 20);

29. LIKE & NOT LIKE
• SELECT * FROM users WHERE last_name = 'Simpson’;
• SELECT * FROM users WHERE last_name LIKE 'Smith%’;
Eg: SELECT * FROM users WHERE last_name LIKE 'Bank%';

30. Example
• SELECT first_name, last_name FROM users WHERE email NOT LIKE
'%@authors.com’;
• SELECT * FROM users WHERE last_name LIKE ' _smith%'

31. Sorting Query
• Syntax :
1.SELECT * FROM tablename ORDER BY column;
2.SELECT * FROM tablename ORDER BY column DESC;
3.SELECT * FROM tablename WHERE conditions ORDER BY column;
4. SELECT * FROM tablename ORDER BY column1, column2
• Eg: SELECT * FROM orders ORDER BY total;

32. Example

33. Example

34. Limiting Query results
• Syntax:
1. SELECT * FROM tablename LIMIT x;
2. SELECT * FROM tablename LIMIT x, y;
3. SELECT which_columns FROM tablename WHERE conditions ORDER
BY column LIMIT x;
Eg:
SELECT * FROM tablename LIMIT 3;
SELECT * FROM tablename LIMIT 10, 10;

35. Example
SELECT first_name, last_name
FROM users ORDER BY
registration_date DESC LIMIT 5;
SELECT first_name, last_name
FROM users ORDER BY
registration_date ASC LIMIT 1, 1;

36. Updating data
• Syntax:
1. UPDATE tablename SET column=value;
2. UPDATE tablename SET column1=valueA, column5=valueB;
3. UPDATE tablename SET column2=value WHERE column5=value;

37. Example
SELECT user_id FROM users
WHERE first_name = 'Michael'
AND last_name='Chabon';
UPDATE users
SET email='mike@authors.com'
WHERE user_id = 18;

38. Deleting Data
• Syntax:
1. DELETE FROM tablename;
2. DELETE FROM tablename WHERE condition;
3. TRUNCATE TABLE tablename;
4. DROP TABLE tablename;
5. DROP DATABASE databasename;

39. Aliases
• SELECT registration_date AS reg FROM users;
• SELECT first_name AS name FROM users WHERE name='Sam’;

40. Using functions
• SELECT FUNCTION(column) FROM tablename;
• SELECT *, FUNCTION(column) FROM tablename;
• SELECT column1, FUNCTION(column2), column3 FROM tablename;

41. Text functions

42. Example
• SELECT CONCAT(t1, t2) FROM tablename;
• SELECT CONCAT(last_name, ', ‘, first_name) FROM users;
• SELECT CONCAT(last_name, ', ', first_name) AS Name FROM users
ORDER BY Name;
• SELECT LENGTH(last_name) AS L, last_name FROM users ORDER BY L
DESC LIMIT 1;
• SELECT CONCAT_WS(' ', first, middle, last) AS Name FROM tablename;

43. Numeric function

44. Example
• SELECT * FROM tablename ORDER BY RAND( );
• SELECT CONCAT('$', FORMAT(5639.6, 2)) AS cost;
• SELECT email FROM users ORDER BY RAND( ) LIMIT 1;
• SELECT MOD(9,2) == SELECT 9%2

45. Date and time function

46. Example
• SELECT DATE(registration_date) AS Date FROM users ORDER BY
registration_date DESC LIMIT 1;
• SELECT DAYNAME(registration_date) AS Weekday FROM users ORDER
BY registration_date ASC LIMIT 1;
• SELECT CURDATE( ), CURTIME( );
• SELECT LAST_DAY(CURDATE( )), MONTHNAME(CURDATE( ));
• ADDDATE( ), SUBDATE( ), ADDTIME( ), SUBTIME( ), and DATEDIFF( ).

47. Formatting the date and time

48. Example
• Time (11:07:45 AM)
= TIME_FORMAT(the_date, '%r')
• Time without seconds (11:07 AM)
= TIME_FORMAT(the_date, '%l:%i %p')
• Date (April 20th, 1996)
=DATE_FORMAT(the_date, '%M %D, %Y’)
• SELECT DATE_FORMAT(NOW( ),'% M % e, % Y %l:%i’);
• SELECT TIME_FORMAT(CURTIME( ),'% T’);
• SELECT email, DATE_FORMAT (registration_date, '%a %b %e %Y’) AS Date
FROM users
• ORDER BY registration_date DESC LIMIT 5;