Www.hope.ac.uk Faculty of Sciences and Social Sciences HOPE PHP & MySQL Stewart Blakeway FML 213...

www.hope.ac.uk Faculty of Sciences and Social Sciences

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PHP & MySQL

Stewart Blakeway

FML 213

[email protected]


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What will we cover

• Basic SQL commands– Inserting Records– Selecting Records– Filtering Records

• Some formatting of controls and displaying of data


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Why

• 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

• MySQL uses all the standard numeric data types.

• Some you will have come across– INT -2147483648 to 2147483647 – TINYING -128 to 127 or 0 to 255– SMALLINT -32768 to 32767 or 0 to 65535– MEDIUMINT -8388608 to 8388607 or 0 to 16777215– BIGINT -9223372036854775808 to

9223372036854775807 or 0 to

18446744073709551615 – FLOAT -10,2 up to 24 places– DOUBLE -16,4 up to 53 places


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Date and Time Types

• DATE - A date in YYYY-MM-DD format• DATETIME - A combination of both the date and the

time, in YYYY-MM-DD & HH:MM:SS

• TIMESTAMP - Similar to DATETIME with hyphens an colons omitted

• TIME - A time in format HH:MM:SS• YEAR(x) - The year, the length is specified

by x.


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String Types

CHAR (x) Fixed lengthVARCHAR (x) Variable lengthBLOB or TEXT Max of 65535 charsTINYBLOB or Max of 255 charsTINYTEXTMEDIUMBLOB or Max of 255 charsMEDIUMTEXT LONGBLOB or Max of 255 charsLONGTEXTENUM A list with a

max 65535 values


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MySQL

• 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

1. Create a connection with the SQL Server

2. Select the appropriate database

3. Construct the SQL Query

4. 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)

• 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

$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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http://hopelive.hope.ac.uk/computing/

2. Selecting the database

• 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

• 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

$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),

firstname varchar (25)

)";

mysql_query ($sql, $conn);

String Variable

PHP command torun the SQL

The variable thatcontains the SQL

The variable thatcontains the connectionsettings


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Retrieving Error Messages

• To ensure that the SQL works you can retrieve error messages and display them!

$result = mysql_query ($sql, $conn) or die(mysql_error());

echo $result;die is optional for all mysql statements

As is mysql_error


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So far!

• 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","");

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 (

‘100100100’,

‘Blakeway’,

‘Stewart’

)";

mysql_query ($sql,$conn) or die(mysql_error());


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Unlikely!

• 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

• 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>”;

}

else{

}

Alternative method. Both the get data and the do data are contained within the one file


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Using Forms

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 formselse // 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!";}else // if not{echo "Record not Added!";}

}

Why not use die(mysql_error()) ?

Can you spot the error?


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Retrieving Data

• 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?Into a RESOURCE


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Getting the data from the RESOURCE

$newArray = mysql_fetch_array($result);

$newArray = array (

“studentId” => “05004343”,

“surname” => “Blakeway”,

“firstname” => “Stewart”

)

The RESOURCE

PHP Function to fetch data from the

RESOURCE


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Moving through multiple records

• Dealing with more than one record!

while ($newArray = mysql_fetch_array($result))

{

$sn = $newArray[‘surname’];

echo $sn . “<br />”;

}


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Combo Boxes

• 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!


{ // display the form

// allow user to choose a record

}

else

{

// display what was selected

}


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Forms!

<form>

<select name=“list”><option value=“surname 1”>

<option value=“surname 2”>

<option value=“surname …”>

</select>

</form>How many surnameswill there be?


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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]\">

Select a Record to View

<select name=\"sel_SN\">

<option value=\"\">-- Select One --</option>";


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The complicated bit


{

$sn = $newArray[‘surname’];

echo "<option value=\"$sn\">

$sn</option>";

}


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The end bit

echo ="

</select>

<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!


{ // display the form

}

else

{

// display what was selected

}


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Displaying the specific recordor the ELSE section

1. Create a connection to the SQL Server

2. Select the required database

3. Construct the SQL

4. Execute the SQL

5. Extract the required data

6. Display the record


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3. Constructing the SQL

• 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);

A variable to hold the resultsof executingthe SQL

The PHP command to executean SQL statement

The variable containing the connectionsettings

The variable containing SQL statement


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5. Extracting the required data from the results


{

$studID = $newArray[‘studentId’];

$studFN = $newArray[‘firstname’];

$studSN = $newArray[‘surname’];

}


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6. Displaying the Record

echo $studFN.$studSN.$studID;

or

echo “<table><tr><td>Id Number</td><td>Forename</td><td>surname</td><tr>

<tr><td>$studID</td><td>$studFN</td><td>$studSN</td></tr></table>”;


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What have we covered?

1. Create a connection to the SQL Server

2. Select the required database

3. Construct the SQL

4. Execute the SQL

5. Extract the required data

6. Display the record


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Class Exercise (time permitting)

• 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

$sql = “CREATE TABLE tablename (

fieldname1 varchar(30),

fieldname2 varchar(30),

)


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Spot the errors

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

• Begin database design and implementation for assessment


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Any Questions?

Www.hope.ac.uk Faculty of Sciences and Social Sciences HOPE PHP & MySQL Stewart Blakeway FML 213...

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