COM621 – Lecture 5

1. COM621 – Lecture 5 MySQL and PHP Integration

2. PHP - MySQL • Commercial Sites: • Apache • PHP • MySQL • XAMP (WAMP – MAMP) • Required Tools • Text Editor or a Program like Dreamweaver

3. Installing XAMP • If you are working from your laptop, it is time to download and install XAMP: • Windows: Download and Install WAMP Server • MAC: Download and Install MAMP • Leave all the settings as default except the browser (change to your preferred browser: I recommend Chrome, Firefox or Safari) • Once Installed, your files for this module need to be stored in the following folder (also applies to the lab machines: c:/wamp/www • Task: Create a folder with your name inside this folder

4. Stopping IIS • Next step (only if you are working in the lab) – you need to stop IIS – go to: • CONTROL PANEL  ADMINISTRATIVE TOOLS  Internet Information Service (IIS) Manager 

5. Stopping IIS • At the top right hand side of the screen click STOP

6. Configuring XAMP • Now is time to Start WAMP Server: • On the desktop click start wampserver; a red “w” icon should appear in your taskbar, it should go from red, to orange to green – once it is green we are ready to go

7. Starting WAMP Start WampServer TaskBar – Red “W”

8. Starting WAMP • Right click on the icon and select: localhost (this should open your browser with the WAMP welcome page)

9. WAMP in Browser

10. Connecting to databases • One of the most common tasks when working with dynamic webpages is connecting to a database which holds the content of the page • PHP has several libraries that allows for communication with many different databases • Some of these libraries have variations in the commands • We will be using the mysql library • Most functions start with mysql_ and then the name of the function

11. Opening a connection • You will need: • The address to the database server • A username with privileges to access the table you require • The username associated password • Optionally: • The name of the database you are connecting

12. Connection Sequence • mysql_connect(host, username, password): returns a link to the host using username and password authentication. • Usage: • $conn=mysql_connect(‘localhost’, ‘myusername’,’MyP455w0rd’) • mysql_select_db(database,link): selects a database from the connection in link • Usage: • mysql_select_db(‘db_name’,$conn);

13. Executing Queries • mysql_query(query,link) is used to run a query on the database server. Required the link and the query string. Returns a result object. • Usage: • $result= mysql_query(“SELECT * from directory”, $conn); • Queries can be constructed as strings and then the string variable can be used on the mysql_query command: • $query="select * from directory"; • $result = mysql_query($query,$link) or die("could not execute:".mysql_error());

14. Working with the results from the query • Result sets are objects. They point to places in memory where the query returned values exist • Result set are NOT the individual rows from the query • You can think of a result set as the TABLE that holds the results • You need to read the rows from that table individually • $row=mysql_fetch_array($result); • Using this function, the array returned can be either numerically indexed or associative! • If there are no more rows, the function returns FALSE

15. Keeping it tidy • Once you have completed your work with the database, there are two things you should do: • Free the results • Close the connection to the server. • Freeing the results can be optional: On closing the connection, the results are automatically freed • If you are planning to run further queries on the same connection, it is good practice to free the previous result set. • mysql_free_result($result); • To close the connection you use • mysql_close($conn);

16. Working with databases – key steps • Design the DB – Create the DB on PHPMyAdmin or MySQL command • Design and Create the HTML • Create a connection • Select the table • Run the query • Verify Insert/Fetch the rows/Do other SQL associated tasks • Display Results as needed • Close the connection

17. MySQL – Data Manipulation Language

18. SQL Data ManipulationLanguage (DML) • SQL is a non procedural language providing syntax for extracting data, including a syntax to update, insert, and delete records. • The Query and Update commands together form the Data Manipulation (DML) part of SQL • SELECT • UPDATE • DELETE • INSERT INTO

19. SQL-DMLSELECT • SELECT: This command is mandatory when performing a query; it is used to retrieve data from a table based on some criteria • It specifies a coma separated list of fields to be retrieved, and the FROM clause specifies the table(s) to be accessed. • The results are stored in a result table known as the result-set. • The * symbol can be used to represent all of the fields

20. SQL-DMLSELECT Format: SELECT column_name(s) FROM table_name Example: SELECT LastName, FirstName, Address FROM Students; To select specified columns, the SELECT command is followed by a comma separated list of fields to be selected from the table

21. SQL-DMLSELECT • SELECT DISTINC: this keyword is used to return only distinct (unique) values from the table. • If there are multiple values of a specified field, the distinct result-set will display only one. Format: SELECT DISTINCT column_name(s) FROM table_name Example: SELECT DISTINCT ShipName FROM Orders;

22. SQL-DMLSELECT • LIMIT(X): this keyword specifies the number of rows to be returned from the beginning of the result-set. X specifies the rows returned Format: SELECT column_name(s) FROM table_name LIMIT X; Example: SELECT ShipName FROM Orders LIMIT 10;

23. SQL-DMLSELECT • WHERE Clause: It is used to select a field when a certain criteria set of conditions are desired • The WHERE Clause is optional • To create the conditions (called selection criteria) SQL provides a set of operators to further qualify what criteria should be specified

24. SQL-DMLWhere Operators

25. SQL-DML • Using Quotes: Quotes are always an issue in programming languages. (single quotes?, double quotes?, when?) • SQL uses single quotes around text values (MySQL also accepts double quotes) • Numeric Values should not be enclosed in quotes.

26. SQL-DML • Comparing Strings: When comparing strings using =, the string must be exactly as typed for the condition to be true – this include length and type of characters. • NULL: Null means that there is not a value in the field, or it is unknown, but does not mean a value of zero.

27. DML-SQL • LIKE – NOT LIKE: The pattern matching operator can be used as a condition in the WHERE clause, allowing the selection of rows that are ‘like’ or match a pattern • A percent sign (%) can be used as a wildcard to match any possible character that might appear before and/or after the character(s) specified. • A _ is used to match a single character. • The LIKE/NOT LIKE condition can be used in any valid SQL statement, including SELECT, INSERT, UPDATE or DELETE.

28. DML-SQL • Examples of the wildcard % uses: • SELECT CompanyName, Country FROM Customers WHERE country LIKE ‘SW%’; • Returns all the customers and countries in which the country starts with “Sw” i.e. Sweden, Switzerland • SELECT City, Country FROM suppliers WHERE City LIKE ‘%o’; • Returns all cities and countries where the % matches any city that ends with a letter o. • SELECT CompanyName FROM customers WHERE CompanyName LIKE ‘%Super%’ • Returns all company names where the % matches any company name that contains the pattern “Super”

29. DML-SQL • Examples of the wildcard _ uses: • SELECT Extension, Firstname FROM Employees WHERE extension LIKE ‘4_ _’; • Returns all extensions and first names where the exetension has three characters and the first character is a 4.

30. DML-SQL • ORDER BY: Used to sort the output of a query in either ascending (ASC, the default) or descending (DESC) order where the values being sorted are either strings or numbers Format: SELECT column_name(s) FROM table_name [WHERE condition] ORDER BY column [ASC, DESC] Example: SELECT Company,Ordernumber FROM Orders ORDER BY Company;

31. SQL-DMLINSERT • The INSERT statement is used ot insert new rows into a table. • After the VALUES keyword, a comma-separated list of column names follows Format: INSERT INTO table_nameVALUES (value1, value2, … ) INSERT INTO table_name (column1, column2,…) VALUES (value1, value2, … ) Example: INSERT INTO Shippers (CompanyName, Phone) VALUES (‘FEDEX’,’416-555-1221’);

32. SQL-DMLINSERT • Usually, the tables have a primary key column that is usually set to auto-increment; when this is the case, the id of the table is created by the database engine automatically • Letting the database increment the PRIMARY KEY ensures that the value is always unique.

33. SQL-DMLUPDATE • The UPDATE statement is used to modify data in a table. • The UPDATE command is followed by the name of the table where the data will be changed, followed by the SET statement to inidcate what field will be changed, and then the new value that will be assigned to the field • The WHERE clause further qualifies what data is to be modified, thereby limiting the scope of the UPDATE

34. SQL-DMLUPDATE Format: UPDATE table_name SET column_name = new value WHERE column_name = some_value; Example: UPDATE orders SET ShipCountry=‘Spain’ WHERE CustomerId = ‘whitc’;

35. SQL-DMLDELETE • The DELETE statement is used to delete rows in a table and returns the number of rows that were deleted. • DELETE uses the FROM clause to specify the name of the table that contains the data you want to delete • The WHERE clause specifies the criteria to identify what data should be removed. BE CAREFUL: Without the WHERE clause ALL ROWS are DELETED

36. SQL-DMLDELETE • If the ORDER BY clause is specified, the rows are deleted in the order that is specified. • The LIMIT clause places a limit on the number of rows that can be deleted. Format: DELETE FROM table_name WHERE column_name = some_value; Example: DELETE FROM orders WHERE ShipCountry = ‘Greenland’;

37. PHPMyAdmin Tutorial LIVE

38. Database Design and Creation Create database ‘hospital’, add a table ‘discharge’ with appropriate fields – patient id, name, appointment type, admission ward, xray examination, mri scan, cat scan, eye test, hearing test, and date (to capture todays date) hospital discharge(patid,name,appointment,ward,xray,mri,cscan,eye,hearing,date)

39. Data details

40. Go ahead and create the database and table using PHPMyAdmin or MySQL command Prompt

41. Data capture form use get to check form is working correct post could also be used, user choice link to php script file <form action="process.php" method="get" name="discharge"> table name Patient Name: <input type="text" name="name" /><br /> <hr /> Appointment type<br /> <select name="appointment"> <option value="GP">General Practicioner</option><br /> <option value="Specialist">Specialist</option><br /> <option value="Surgery">Surgery</option><br /> </select> 3 options for app type

42. Radio button Admission to Wards:<br /> <label> <input type="radio" name="ward" value="No" /> No Ward</label> <br /> <label> <input type="radio" name="ward" value="A" /> Ward A</label> <br /> <label> <input type="radio" name="ward" value="B" /> Ward B</label> <br /> <label> <input type="radio" name="ward" value="C" /> Ward C</label> <br /> <hr /> 4 options via radio buttons, only one can be selected on form

43. Checkboxes Treatments Undertaken:<br /> <input type="checkbox" name="xray" value="yes" />X-Ray Treatment<br /> <input type="checkbox" name="mri" value="yes" />MRI Scan<br /> <input type="checkbox" name="cscan" value="yes" />CAT Scan<br /> <input type="checkbox" name="eye" value="yes" />Eye Test<br /> <input type="checkbox" name="hearing" value="yes" />Hearing Test<br /> <hr /> 5 options, any can be selected on form

44. Submit/reset button <input type="submit" value="Submit Form" /> <input type="reset" value="Reset Form" /> </form>

45. PHP-process.php Open a new file, save as process.php, keep on same directory as html file single option data passing $_POST option also viable, keep consistent with previous use <?php $id = $_GET['patid']; $name = $_GET['name']; $app = $_GET['appointment']; $ward = $_GET['ward']; $string

46. Checkbox data selection checkboxes allow multiple options if not checked, it will not pass the parameter (not set) if passed the default is set to ‘yes’ so if not passed, we need to assign a value to the respective variable that will go into the database if (isset($_GET['xray'])) { $xray = $_GET['xray']; } else { $xray = "No"; } Note: This code needs to be repeated for every checkbox variable passed as a parameter the variables used are: $mri, $cscan, $eye, $hearing

47. print "Name:".$name."<br />"; print "Appointment:".$app."<br />"; print "Ward:".$ward."<br />"; print "X-Ray:".$xray."<br />"; print "MRI:".$mri."<br />"; print "CSCAN:".$cscan."<br />"; print "EYE:".$eye."<br />"; print "HEARING:".$hearing."<br />"; print used to check fields are being passed and captured in the page

48. Database connection $link = mysql_connect('localhost','student','student') or die(mysql_error()); mysql_select_db('hospital',$link);

49. Current date selection This script demonstrates how the current date can be obtained from the MySQL server using the appropriate DATE query $querydate = "SELECT CURDATE() as Today"; $result1 = mysql_query($querydate,$link) or die(mysql_error()); $row = mysql_fetch_assoc($result1); $today = $row['Today']; The parameter being queried (date) does not have an index in the array, so we need to use the alias “AS” to assign an index that we can use to retrieve from the result array

50. INSERT data Query to insert all data from html form + date obtained from previous query $query = "INSERT INTO discharge VALUES (NULL,'$name','$app','$ward','$xray','$mri','$cscan','$eye','$hearing','$today')"; $result = mysql_query($query,$link) or die(mysql_error()); $affected = mysql_affected_rows($link); if ($affected >0) {echo "success";} else {echo "fail";} generates my-sql error causes detects affected rows in the query in this case 1 row was INSERTED so $affected=1 if the insert was successful