2. Website Development & Management PHP Odds & Ends Instructor: John Seydel, Ph.D. CIT 3353 -- Fall 2006 www.clt.astate.edu/jseydel/mis3353

3. Student Objectives Upon completion of this class meeting, you should be able to: Summarize the steps involved in using PHP to accomplish basic database queries Use PHP to display database contents to a web page Create an onLoad event handler for a web page

4. Using PHP to Interface with MySQL Always starts with the creation of a connection Requires opening a database Generally involves generating a recordset (aka, result set) Processing the recordset typically involves some sort of looping construct One repetition per record Must be controlled by some sort of counter: foreach(), while(), and for() Makes use of several important functions...

5. PHP Functions for Basic Queries Create a connection: mysql_connect() Arguments (string): server, userID, password Returns a string (connection information) Open a database: mysql_select_db() Arguments (string): database to be used, connection Returns a boolean value Create a recordset: mysql_query() Arguments (string): SQL query, connection Returns a recordset (an array of data) Process a recordset: mysql_num_rows()  Argument (array): recordset  Returns an integer (number of records) mysql_fetch_array()  Arguments (string): recordset  Returns a row from the recordset

6. Let’s Complete the First Database Exercise Where we left off: Initial values assigned Connection created Database opened Recordset created Note: three line equivalent (poor coding) What’s left: Process the records (a row at a time)  Get data for each row in the database table  Assign those data to variables  Add to the output block Incorporate output block into the HTML section

7. A Bit More on QueriesQueries Not just getting information from a database Also involves putting information into a database Creating databases Creating tables Adding records to tables Modifying (updating) existing records Require the use of SQL (structured query language), a universal database language Reference material: so far, mostly the class notes

8. Summary: What We’ve Seen Recently New PHP functions mysql_connect() mysql_select_db() mysql_query() mysql_num_rows() mysql_fetch_array() A little SQL Used directly with MySQL Incorporated into PHP script The for() construct How to use PHP to connect to MySQL, open a database, create a recordset, and process that recordset How/where MySQL files are storedstored

9. The FKAuto Database Files For use on your own computer: Download these Available in the Documents directory (not public_html) of the cit3353 account on SuSE1  Recall the password?  All three files for the UsedCars database are in a directory named fkauto For use on SuSE1: don’t worry about where they are, as they are available to your scripts However, the “owner” is user cit3353 Thus use the appropriate values for user and password

10. Some Other Things: FKAuto Calculator Page (calc.php) JavaScript: used within the onLoad event handler for the element Note the arrays Use of the range() function Alternatively, but more work: array() foreach() construct

11. Appendix

12. How MySQL Stores the Data Each table (i.e., relation) involves three files: TableName.frm TableName.MYD (where the actual data are) TableName.MYI The files for all the tables belonging to a given database are stored in a directory with the same name as the database All database directories are stored in the data directory within c:\mysql

13. Working with MySQL Get started mysql -u jojobeans –p USE testDB; SHOW TABLES; Using tables CREATE TABLE tblTest (testID int, testNote text); EXPLAIN tblTest; SELECT * FROM tblTest; INSERT INTO tblTest VALUES (123,’First entry’); INSERT INTO tblTest VALUES (456,’Second entry’); SELECT * FROM tblTest; QUIT;