COM621 – Lecture 5

MySQL and PHP Integration

PHP - MySQL

• Commercial Sites:– Apache– PHP– MySQL– XAMP (WAMP – MAMP)

• Required Tools– Text Editor or a Program like Dreamweaver

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

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

Stopping IIS– At the top

right hand side of the screen click STOP

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

Starting WAMP

Start WampServer TaskBar – Red “W”

Starting WAMP• Right click on the icon and

select: localhost (this should open your browser with the WAMP welcome page)

WAMP in Browser

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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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

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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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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());

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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

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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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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

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MySQL – Data Manipulation Language

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

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

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

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;

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;

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

SQL-DMLWhere Operators

Operator Description Example

= Equal to WHERE country = ‘ireland’

<>, != Not equal to WHERE country != ‘USA’

> Greater than WHERE salary > 28000

< Less than WHERE age < 35

>=, <= Greater/Less Than or Equal WHERE cost >=1200

IS [NOT] NULL Is NULL (vo value) or Not NULL WHERE birth = NULL

BETWEEN Between an inclusive range WHERE last_name BETWEEN ‘Doherty’ AND ‘McDAID’

LIKE Search for a value like a pattern WHERE name LIKE ‘D%’

NOT LIKE Search for a value not like a pattern WHERE country NOT LIKE ‘Sw%’

! , NOT Logical not for negation WHERE age ! 10;

||, OR Logical OR WHERE order_number > 10 || part_number = 80

&&, AND Logical AND WHERE age>12 && age < 21

XOR Exclusive OR WHERE status XOR

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.

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.

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.

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”

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.

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;

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_name VALUES (value1, value2, … )

INSERT INTO table_name (column1, column2,…) VALUES (value1, value2, … )

Example:INSERT INTO Shippers (CompanyName, Phone) VALUES (‘FEDEX’,’416-555-1221’);

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.

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

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’;

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

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’;

PHPMyAdmin Tutorial

LIVE

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

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

Data capture form

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

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>

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

table name

3 options for app type

Radio buttonAdmission 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 button

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

PHP-process.php

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

$string

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

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

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

Database 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

INSERT data

$query = "INSERT INTO discharge VALUES (NULL,'$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 my-sql error causes

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

Selection to display all

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

This is another query to retrieve all the datafrom the table discharge

Table design for results

<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 are the fields 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

Close connection

<?phpmysql_close($link);?>

Deleting Records• HTML Button to call delete statements:

• Query to Delete Data from the Database:

<form action="delete.php" method="get"><label>Patient ID:<input type="text" name="patid" /></label><input type="submit" value="Delete Record" /></form>

<?php$patid=$_REQUEST['patid'];$query = "DELETE from discharge WHERE patid=$patid";$result = mysql_query($query,$link) or die(mysql_error());$affected = mysql_affected_rows($link);

if ($affected >0) {echo "success";} else {echo "fail";}?>

Obtaining patid fromform

User Feedback

Remember to add the connection linesusing $link to connect to the db

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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