PHP+MySQL Integration

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

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Working with databases –key steps

1. Design the DB– Create the DB on PHPMyAdmin or MySQL

command2. Design and create the HTML3. Create a connection and select the database4. Run the query– Verify Insert/Fetch the rows/Do other SQL

associated tasks5. Display Results as needed6. Close the connection

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1. 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)

hospitaldischarge (patid,name, appointment, ward, xray, mri, cscan, eye, hearing, date)

Data details

Field Type Comment

patid int(11) NN AI PK Primary Key Index

name varchar(45) Patient Full Name

appointment varchar(11) type of appointment:GP, Specialist or Surgery

ward char(2) Admitted to ward? No, or ward A,B or C

xray char(3) x-rays taken? YES,NO

mri char(3) mri carried out? YES,NO

cscan char(3) CAT scan carried out? YES,NO

eye char(3) eye test carried out? YES,NO

hearing char(3) hearing test carried out? YES,NO

date date date of discharge: format YYYY-MM-DD as text

2. Design and Create the HTML

In order to interact with the database we need a data capture form, and a script that will process the form.

Create an HTML document in the folder you created in C:\wamp\www, and save it as hospital.html

hospital.html<form action="process.php" method="get" name="discharge">Patient name: <input name="name" type="text" /><br/><hr/>Appointment type: <select name="appointment"> <option value="General Practitioner">GP</option> <option value="Specialist">Specialist</option> <option value="Surgery">Surgery</option></select><hr/>Admission to these Wards:<br/> <label> <input type="radio" name="ward" value="No" id="ward_0" /> No Ward</label> <br /> <label> <input type="radio" name="ward" value="A" id="ward_1" /> Ward A</label> <br /> <label> <input type="radio" name="ward" value="B" id="ward_2" /> Ward B</label> <br /> <label> <input type="radio" name="ward" value="C" id="ward_3" /> Ward C</label> <br /><hr/>Treatments Undertaken:<br/><input name="xray" type="checkbox" value="yes" />X-Ray Treatment<br/><input name="mri" type="checkbox" value="yes" />MRI Scan<br/><input name="cscan" type="checkbox" value="yes" />CAT Scan<br/><input name="eye" type="checkbox" value="yes" />Eye Test<br/><input name="hearing" type="checkbox" value="yes" />Hearing Test<br/><hr/><input name="" type="submit" value="Submit Form" /><input name="" type="reset" value="Reset Form" /></form>

Form

<form action="process.php" method="get" name="discharge">

link to php script fileuse get to check form is working correctlypost could also be used, user choice

form name

Drop down list

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 appointment type

Radio buttonsAdmission 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 radiobuttons, only one canbe selected on form

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

Submit/reset buttons

<input type="submit" value="Submit Form" />

<input type="reset" value="Reset Form" />

</form>

process.php

<?php$name = $_GET['name'];$app = $_GET['appointment'];$ward = $_GET['ward'];

$variable

single option data passing

$_POST option also viable, keep consistent withprevious use

Open a new file, save as process.php, keep on same directory as html file

Arguments are passed as below:http://localhost/process.php?name=Joe+Bloggs&appointment=General+Practitioner&ward=A

Checkbox data selection

if (isset($_GET['xray'])) {$xray = $_GET['xray'];} else {

$xray = "No";}

Note: This code needs to be repeated for every checkbox variable passed as a parameterthe variables used are:$mri, $cscan, $eye, $hearing

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 assigna value to the respective variable that will go into the database

Check data capture

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 beingpassed and captured in the page

3. Database 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 to

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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);

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Opening a connection

$link = mysql_connect('localhost','student','student') or die(mysql_error());

mysql_select_db('hospital',$link);

Current date selection

$querydate = "SELECT CURDATE() as Today";$result1 = mysql_query($querydate,$link) or die(mysql_error());$row = mysql_fetch_assoc($result1);$today = $row['Today'];

This script demonstrates how the current datecan be obtained from the MySQL server using the appropriate DATE query

The parameter being queried (date)does not have an index in the array,so we need to use the alias “AS” to assignan index that we can use to retrieve fromthe result array

4. Run the query

mysql_query(link, query) is used to run a query on the database server. It requires the link and the query string and returns a result object.Usage:

$result= mysql_query(“SELECT * from directory”, $conn);

Queries can be constructed as strings. The string variable can then be used on the mysql_query command.Usage:

$query="select * from directory";$result = mysql_query($query,$link) or die("could not execute:".mysql_error());

Insert 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";}

detects affected rows in the queryin this case 1 row was INSERTED so$affected=1 if the insert was successful

generates mysql error causes

Query to insert all data from html form + date obtained from previous query

Specify discharge table

Select query

$query3 = "SELECT * FROM discharge";$result3 = mysql_query($query3,$link) or die(mysql_error());$row3 = mysql_fetch_assoc($result3);?>

This query will retrieve all the data from the table discharge

5. Display results

•Result sets are objects. They point to places in memory where the values returned from the query exist•Result sets 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

Table headings

<table width="200" border="1"> <tr> <th scope="col">Patient ID</th> <th scope="col">Patient Name</th> <th scope="col">Appointment Type</th> <th scope="col">Admitted to Ward</th> <th scope="col">X-Ray</th> <th scope="col">MRI</th> <th scope="col">Cat Scan</th> <th scope="col">Eye Test</th> <th scope="col">Hearing Test</th> <th scope="col">Date Discharged</th> </tr>

Results

<tr> <td><?php echo $row3['patid']; ?></td> <td><?php echo $row3['name']; ?></td> <td><?php echo $row3['appointment']; ?></td> <td><?php echo $row3['ward']; ?></td> <td><?php echo $row3['xray']; ?></td> <td><?php echo $row3['mri']; ?></td> <td><?php echo $row3['cscan']; ?></td> <td><?php echo $row3['eye']; ?></td> <td><?php echo $row3['hearing']; ?></td> <td><?php echo $row3['date']; ?></td> </tr></table>

$row is an associative array containing the results,the index of the array is the field in the database

do …. while loop

<?php do { ?> <tr> <td><?php echo $row3['patid']; ?></td> <td><?php echo $row3['name']; ?></td> <td><?php echo $row3['appointment']; ?></td> <td><?php echo $row3['ward']; ?></td> <td><?php echo $row3['xray']; ?></td> <td><?php echo $row3['mri']; ?></td> <td><?php echo $row3['cscan']; ?></td> <td><?php echo $row3['eye']; ?></td> <td><?php echo $row3['hearing']; ?></td> <td><?php echo $row3['date']; ?></td> </tr><?php } while ($row3=mysql_fetch_assoc($result3)); ?></table>

DO-WHILE Loopneeded to display all the results of the database

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);

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6. Close connection

<?phpmysql_close($link);?>

Places where things can go wrong

• Creating a connection– Server unreachable/offline– Wrong username/password combination

• Selecting the table– Table does not exist– User without privileges for that table

• Running the query– Syntax errors– Empty result set

• Fetching results– Misusing the array

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