1. 1 CS428 Web Engineering Lecture 23 MySQL Basics (PHP - VI)

2. In order to have really full featured application. We are going to need to incorporate a database. We can store lots of information in database, search through it. Added it, updated. Keep it there for long period of time. There are so many benefits of using database. INTRODUCTION

3. CRUD CRUD is acronym and it stands for… CRUD Create, Read, Update, Delete These are the basic operations perform on the data base.

4. We create records in the database. We read records back in the database. We update records in the database. We completely delete records in the database.

5. SQL SELECT (Read) Format: SELECT * FROM table WHERE column1 = ‘some_text’ ORDER BY column1, column2 ASC;

6. SQL INSERT (Create) Format: INSERT INTO table (column1, column2, column3) VALUES (val1, val2, val3);

7. SQL UPDATE (Update) Format: UPDATE table SET column1 = ‘some_text’ WHERE id = 1;

8. SQL DELETE (Delete) Format: DELETE FROM table WHERE id = 1;

9. CREATE COMMAND CREATE DATABASE widget_corp; USE widget_corp; CREATE TABLE subjects ( id int(11) NOT NULL auto_increment, menu_name varchar(30) NOT NULL, position int(3) NOT NULL, visible tinyint(1) NOT NULL, PRIMARY KEY (id) );

10. INSERT COMMAND INSERT INTO subjects (menu_name, position, visible) VALUES (‘About Widget Corp’, 1, 1); SELECT * FROM subjects; INSERT INTO subjects (menu_name, position, visible) VALUES (‘Products’, 2, 1); INSERT INTO subjects (menu_name, position, visible) VALUES (‘Services’, 3, 1); INSERT INTO subjects (menu_name, position, visible) VALUES (‘Misc’, 4, 0);

11. SELECT COMMAND SELECT * FROM subjects WHERE visible = 1 ORDER BY position ASC/DESC; SELECT id, menu_name FROM subjects WHERE visible = 1 ORDER BY position ASC/DESC;

12. UPDATE COMMAND UPDATE subjects SET visible = 1 WHERE id = 4;

13. PHPMyAdmin www.phpmyadmin.net It is already included in WAMP/XAMP one package. http://localhost/phpmyadmin

14. Using PHPMyAdmin It enables you to access your MySQL database through a GUI. You can easily do the following: Drop and create databases Create, edit and delete tables Create, edit and delete fields Enter any MySQL statements View and Print table structure Generate PHP code View data in table format

15. PHP with MySQL

16. PHP Database Interaction in FIVE steps 1.Create a database connection 2.Select a database to use 3.Perform database query 4.Use returned data (if any) 5.Close connection

17. COMMONLY USED FUNCTIONS mysql_connect(“hostname”,”user”,”pass”); mysql_select_db(“database name”, “handle”); mysql_query(“query”); mysql_num_rows(result variable from query); Connects to MySQL server. Selects a database to use. Execute database query Return number of rows, after execution of query

18. mysql_fetch_array(“result variable from query”); mysql_fetch_assoc(“result variable from query”) Used to return several rows of the entire results of a database query

19. mysql_error(); md5(string); Shows the error message that has been returned directly from MySQL server. It uses is to encrypt a string. It returns 32 characters hexadecimal number

20. md5() Example: $str = “Hello”; echo md5($str); Output: 8bla9953c4611296a827abf8c47804d7

21. date() Example: echo date(“Y”); // 2015 (year) echo date(“m”);// 12 (month) echo date(“d”); // 27 (day) echo date(“Y-m-d”); // 2015-01-27 echo date(“d/m/y”);// 28/12/15 echo date(“F d, Y”);// January 28, 2015 echo date(“F j, Y, h:i:s a”); // September 28, 2015, 12:12:35 AM

22. STEP 1 <?php // 1. Create a database connection $connection = mysql_connect(“localhost”, “root”, “password”); if (!$connection) { die(“Database connection failed: ”. mysql_error()); } ?> … this function returns a value, that will stored in $connection. That value is called handle.

23. STEP 2 <?php // 1. Create a database connection $connection = mysql_connect(“localhost”, “root”, “password”); if(!$connection) { die(“Database connection failed: ”. mysql_error()); } // 2. Select a database to use $db_select = mysql_select_db(“widget_corp”, $connection); if(!$db_select) { die(“Database selection failed: ”. mysql_error()); } ?> …

24. STEP 3 Step 1 (create a database connection) Step 2 (select a database to use) <?php // 3. Perform database query $result = mysql_query(“SELECT * FROM subjects”, $connection); if (!result) { die(“Database query failed: ”. mysql_error()); } ?>

25. STEP 4 … <?php // 3. Perform database query $result = mysql_query(“SELECT * FROM subjects”, $connection); if (!result) { die(“Database query failed: ”. mysql_error()); } // 4. Use returned data while ($row = mysql_fetch_array($result)) { echo $row[1]. “ ”. $row[2]. “ ”; } ?>

26. STEP 5 Step 1 Step 2 Step 3 Step 4 <?php // 5. Close connection mysql_close($connection); ?>

27. EXAMPLE Create a database name school in MySQL. Create a table name result, with following fields sId, sName and Marks. Create a file name connection.php

28. EXAMPLE: STEP 1 Create connection <?php // 1. create a connection $connection = mysql_connect(“localhost”,”root”,””); if(!connection) { die(“database connection failed”. mysql_error()); } ?>

29. EXAMPLE: STEP 2 <?php // 1. Create a database connection $connection = mysql_connect(“localhost”, “root”, “password”); if (!$connection) { die(“Database connection failed: ”. mysql_error()); } // 2. Select a database to use $db_select = mysql_select_db(“school”, $connection); if(!$db_select) { die(“Database selection failed: ”. mysql_error()); } ?> …

30. EXAMPLE: STEP 3 Step 1 (create a database connection) Step 2 (select a database to use) <?php // 3. Perform database query $query = “SELECT * FROM result”; $result = mysql_query($query, $connection); if (!$result) { die(“Database query failed: ”. mysql_error()); } if(mysql_num_rows($result <= 0)){ die(“No record found”); } ?>

31. EXAMPLE: STEP 4 Step 1 (create a database connection) Step 2 (select a database to use) … <?php Step 3 (perform database query) // 4. Use returned data while ($row = mysql_fetch_array($result)) { echo $row[0]. “ ”; echo $row[1]. “ ”; echo $row[2]. “ ”; } ?>

32. EXAMPLE: STEP 5 Step 1 Step 2 Step 3 Step 4 <?php // 5. Close connection mysql_close($connection); ?>