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HOPE
PHP & MySQL
Stewart Blakeway
FML 213
[email protected]
www.hope.ac.uk
Faculty of Sciences and Social Sciences
What will we cover
• Basic SQL commands
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– Inserting Records
– Selecting Records
– Filtering Records
• Some formatting of controls and displaying of
data
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Why
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•
As part of your assessment you will be
expected to
1. Create a link to the SQL Server
2. Select a database
3. Talk to the database (retrieve, add, append, etc)
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Data Types
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• MySQL uses all the standard numeric data
types.
• Some you will have come across
–
–
–
–
–
INT
TINYING
SMALLINT
MEDIUMINT
BIGINT
– FLOAT
– DOUBLE
-2147483648 to 2147483647
-128 to 127 or 0 to 255
-32768 to 32767 or 0 to 65535
-8388608 to 8388607 or 0 to 16777215
-9223372036854775808 to
9223372036854775807 or 0 to
18446744073709551615
-10,2 up to 24 places
-16,4 up to 53 places
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Date and Time Types
• DATE
• DATETIME
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• TIMESTAMP
• TIME
• YEAR(x)
- A date in YYYY-MM-DD format
- A combination of both the date and the
time, in YYYY-MM-DD & HH:MM:SS
- Similar to DATETIME with hyphens an
colons omitted
- A time in format HH:MM:SS
- The year, the length is specified by x.
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String Types
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CHAR (x)
VARCHAR (x)
BLOB or TEXT
TINYBLOB or
TINYTEXT
MEDIUMBLOB or
MEDIUMTEXT
LONGBLOB or
LONGTEXT
ENUM
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Fixed length
Variable length
Max of 65535 chars
Max of 255 chars
Max of 255 chars
Max of 255 chars
A list with a max 65535 values
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MySQL
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• In order to complete your assignment you will
need to create a database
• The database will be empty, the structure
you will need to define
• The database and the tables should be
named appropriately
• The fields within the database should be of a
suitable type
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Talking to the DATBASE
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1.
2.
3.
4.
Create a connection with the SQL Server
Select the appropriate database
Construct the SQL Query
Execute the SQL Query
Have you created the DATABASE yet? Although you
could use SQL statements to create the database
and the tables within the database, a utility called
phpMyAdmin offers an GUI to do the same task.
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1. The Connection
mysql_connect($host,$user,$password)
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• host is the SQL server address
• user is the username to login to the database
• password is the password associated with the
username
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1. The Connection Syntax
• Storing and testing the connection
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$conn = mysql_connect (“localhost",“root","")
or die(mysql_error());
echo $conn;
• Should echo out: Resource id #1 or Resource id
#2
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2. Selecting the database
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• There could be many databases on the SQL
server. You need to ensure you select the
correct one:
mysql_select_db(database,connection)
• database is the name of the database
• connection is the connection parameters to connect
to the SQL server as seen in the previous slide
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2. Selecting the database Syntax
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• There could be many databases on the SQL
server. You need to ensure you select the
correct one:
mysql_select_db(“student",$conn) or
die(mysql_error());
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3. Constructing the SQL Query
• To interact with the database you construct
standard MYSQL statements
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$sql = “CREATE TABLE tablename (
fieldname1 datatype,
fieldname2 datatype
)”;
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4. Executing the SQL Query
$sql = "CREATE TABLE student(
studentId int not null primary key,
surname varchar (25),
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firstname varchar (25)
)";
String Variable
mysql_query ($sql, $conn);
PHP command to The variable that The variable that
run the SQL
contains the SQL contains the
connection
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Retrieving Error Messages
• To ensure that the SQL works you can
retrieve error messages and display them!
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$result = mysql_query ($sql, $conn) or
die(mysql_error());
echo $result;
die is optional
for all mysql
statements
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As is
mysql_error
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So far!
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• We have connected to the SQL Server
• We have selected the correct database
• We have created a table called student with
3 fields.
• studentId
• surname
• firstname
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All together
$conn = mysql_connect (“localhost",“root","");
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mysql_select_db(“student",$conn);
$sql = "CREATE TABLE student(
studentId int not null primary key,
surname varchar (25),
firstname varchar (25)
)";
mysql_query ($sql, $conn);
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Inserting DATA
The next step is to insert data into your
table.
$sql = "INSERT INTO student VALUES (
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‘100100100’,
‘Blakeway’,
‘Stewart’
)";
mysql_query ($sql,$conn) or die(mysql_error());
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Unlikely!
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• It is very unlikely that you will enter
predetermined data into a database
• This is very useful for testing purposes
• More likely you will need to obtain the data
via the user
• How do we achieve this?
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2 Methods
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• Create the form in html and send the data to
another file – we have all been doing this
already
• Create the form in php and send the data to
the same file – it is easier to work with one
file rather than switching between two
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if ($_POST[viewed] != "yes")
{
echo “<form method=\"POST\“ action=\"$SERVER[PHP_SELF]\">
<input type=\"hidden\“ name=\"viewed\" value=\"yes\">
</form>”;
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}
else
{
}
Alternative method.
Both the get data
and the do data are
contained within the
one file
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Using Forms
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if ($_POST[op]!="viewed")
{
echo "<form id=\"form1\" name=\"form1\" method=\"post\"
action=\"$_SERVER[PHP_SELF]\">
Student ID Number
<input type=\"text\" name=\"studID\" /> <br />
Student Forename
<input type=\"text\" name=\"studFN\" /> <br />
Student Surname
<input type=\"text\" name=\"studSN\" /> <br />
<input type=\"hidden\" name=\"op\" value=\"viewed\">
<input type=\"submit\" name=\"submit\" value=\"Add
Record\">
</form>";
}
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Processing data from forms
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else // if it has then add the data
{
//set sql string using values as indicated by the form
$sql = "INSERT INTO tblstudent VALUES (
'$_POST[studID]',
'$_POST[studSN]',
'$_POST[studFN]')";
}
if (mysql_query($sql,$conn)) // is it valid?
{
echo "Record Added!";
}
Why not use
Can you spot
else // if not
die(mysql_error())
?
the error?
{
echo "Record not Added!";
}
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Retrieving Data
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• At some point you will want to retrieve the data
from the database. Immediately after you insert
data for the first time would be a good time!
$sql = "SELECT * FROM student“;
$result = mysql_query ($sql,$conn);
• Where does the data go?
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Into a RESOURCE
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Getting the data from the RESOURCE
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$newArray = mysql_fetch_array($result);
$newArray = array (
“studentId” => “05004343”,
“surname” => “Blakeway”,
“firstname” => “Stewart”
)
PHP Function to fetch data
from the RESOURCE
The RESOURCE
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Moving through multiple records
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• Dealing with more than one
record!
while ($newArray = mysql_fetch_array($result))
{
$sn = $newArray[‘surname’];
echo $sn . “<br />”;
}
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Combo Boxes
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• As you can see from the last slide each
surname is displayed on screen
• What if you wanted to put the names in a big
list for the user to select one?
• This is fairly straightforward once it has been
thought through
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Overall structure of the page!
if ($_POST[viewed] != "yes")
{
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// display the form
// allow user to choose a record
}
else
{
// display what was selected
}
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Forms!
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<form>
<select name=“list”>
<option value=“surname 1”>
<option value=“surname 2”>
<option value=“surname …”>
</select>
</form>
How many surnames
will there be?
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HOPE
3 Steps
1. First bit of the form
2. THE LOOPING (SURNAMES or whatever)
3. The last bit of the form
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The first bit
echo "<form method=\"POST\“
action=\"$SERVER[PHP_SELF]\">
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Select a Record to View
<select name=\"sel_SN\">
<option value=\"\">-- Select One --</option>";
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The complicated bit
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while ($newArray =
mysql_fetch_array($result))
{
$sn = $newArray[‘surname’];
echo "<option value=\"$sn\">
$sn</option>";
}
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The end bit
echo ="
</select>
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<input type=\"hidden\" name=\"viewed\"
value=\"yes\">
<input type=\"submit\" name=\"submit\"
value=\"View Selected Entry\">
</form>";
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Overall structure of the page!
if ($_POST[viewed] != "yes")
{
// display the form
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}
else
{
// display what was selected
}
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Displaying the specific record
or the ELSE section
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1.
2.
3.
4.
5.
6.
Create a connection to the SQL Server
Select the required database
Construct the SQL
Execute the SQL
Extract the required data
Display the record
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3. Constructing the SQL
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• Now we have specific criteria for data that needs to
be SELECTED from our record set
$sql = "SELECT * FROM student";
$sql = "SELECT * FROM student WHERE surname =
'$_POST[sel_SN]'";
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4. Executing the SQL
$result = mysql_query ($sql, $conn);
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A variable to
hold the results
of executing
the SQL
The PHP
command
to execute
an SQL
statement
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The
variable
containing
SQL
statement
The variable
containing
the
connection
settings
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5. Extracting the required data
from the results
while ($newArray = mysql_fetch_array($result))
{
$studID = $newArray[‘studentId’];
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$studFN = $newArray[‘firstname’];
$studSN = $newArray[‘surname’];
}
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6. Displaying the Record
echo $studFN.$studSN.$studID;
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or
echo “<table><tr><td>Id
Number</td><td>Forename</td><td>s
urname</td><tr>
<tr><td>$studID</td><td>$studFN</td
><td>$studSN</td></tr></table>”;
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What have we covered?
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1.
2.
3.
4.
5.
6.
Create a connection to the SQL Server
Select the required database
Construct the SQL
Execute the SQL
Extract the required data
Display the record
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Class Exercise (time permitting)
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• Create a function called nowAdd that will add
the data obtained from a form to a database
called dbCourse.
•
•
•
•
•
Posted name attributes are: fName, sName
Database table is: tblStudent
SQL server is located at: localhost
SQL Username is: tutor
SQL Password is: mypw
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Spot the errors
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$sql = “CREATE TABLE tablename (
fieldname1 varchar(30),
fieldname2 varchar(30),
)
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Spot the errors
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while ($newArray == mysql_fetch($result))
{
$studID => $newArray[‘studentID’];
$studFN => $newArray[‘firstname’];
$studSN => $newArray[‘surname’];
};
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What next?
• Independent Study:
http://www.w3schools.com/sql/default.asp
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• Begin database design and implementation
for assessment
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Any Questions?
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