Database 20/2/12 Connection

Lecture 7Database

20/2/12 Connection

http://www.connectionstrings.com/

Useful Link

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Database Connections

Client PCRequest Data stored on DB

Db

Web Server – Corvus 3

Data retrieved from Db and sent to browser window

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This ability to access multiple types of data stores with a relative simple and flat object model, make ADO the simplest method yet devised for retrieving data

◦ ADO works with ODBC compliant sources

ADO – ActiveX Data Objects.

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The Connection Object is used to hold information about the data store you want to access

Because it is an Object it has properties and methods

Some of these will be needed when creating you PHP application

Connection Object

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Before you can retrieve any data from a database, you have to create and initalise a connection to that database

ADODB contains all the ADO objects that you will need to use

In order to use any of the Object from the ADO Object Model you will need to create them

PHP uses the following syntax for creating an Instance of an object

$conn = new COM ("ADODB.Connection") or die("Cannot start ADO");

Note: we store the connection in a variable ($conn) for later use in the script. The "die" part will beexecuted if the connection fails.

The Connection Object

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Connection String ‘tells’ your connection what database you wish to connect to.

If you have a system DSN set up all you need do is supply this when setting the connection String.

This is the simplest form of string that can be used.

The connection can also be used for a DSN-less connection.

Connection String

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$connStr = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\MBSEBus\CHeavin\Databases\cus.accdb";

Note: WWWRoot is a hidden folder (by default) and can't be displayed in directory

listing

Connection String

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Connection strings are string variables which contain database connection information and then passed to ADO(ActiveX Data Objects) which will interpret them and act accordingly

They need to be in a comprehensible for ADO format

If you're connecting to an MS Access database, you need the DRIVER, and the DBQ, and some other optional information

Connection String

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When the you have created an instance of the connection object and you have created the assigned a connection string you then need to explicitly open the connection to the database.

To open a connection:$conn->open($connStr);

If the Open method executes you have a working connection to the database

Opening the connection.

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As with any Object you need to free the memory associated with it when you are finished.

However, before you do that, you need to close the connection

$conn->Close();

Closing the Connection

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If you wanted to close the connection but connect to a different data source, you can use the same instance of the connection object.

Simply close the connection first, the set the connection information appropriately and, and reopen it.

Closing the connection.

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Setting up the recordset$rS = $conn->execute("SELECT * FROM test");

RecordSet

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After connecting to a database. You may want to do all or some of the following:

◦ Read Data◦ Write Data◦ Delete Data

Reading Data from a Database

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◦ Recordset is simply a set of records.◦ The Recordset may be used to contain a subset of all the records in a table All the records in a table. A specifically chosen set of records

Using a specific SQL statement.

You will need to create an instance of the recordset object before you can use it

Reading Data from a Database

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$rS = $conn->execute("SELECT * FROM test"); $f1 = $rS->Fields(0); $f2 = $rS->Fields(1); while (!$rS->EOF) { print $f1->value." ".$f2->value."<br />\n"; $rS->MoveNext(); } $rS->Close();

Recordset

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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head><meta content="text/html; charset=windows-1252" http-equiv="Content-Type" /><title>Untitled 1</title></head>

<body><?php

//create an instance of the ADO connection object$conn = new COM ("ADODB.Connection") or die("Cannot start ADO");

//define connection string, specify database driver$connStr = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\MBSEBus\CHeavin\

Databases\cus.accdb";

//Open the connection to the database $conn->open($connStr);

echo "Connection Open<br>";//recordset code$rS = $conn->execute("SELECT * FROM test");

$f1 = $rS->Fields(0); $f2 = $rS->Fields(1); while (!$rS->EOF) { print $f1->value." ".$f2->value."<br />\n"; $rS->MoveNext(); } $rS->Close(); $conn->Close(); ?></body>

</html>

Select Records

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Example:

$sql="UPDATE test SET name='Mary' WHERE name='Ciaran'";

Update SQL

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<body><?php


//define connection string, specify database driver$connStr = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\mbsebus\CHeavin\



echo "Connection Open<br>";

$sql="UPDATE test SET name='Ciara' WHERE name='harry'";

$rS = $conn->execute($sql); echo "Record Updated<br>";$conn->Close(); ?>

</body>

</html>

Update Records

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$sql="DELETE * FROM test WHERE name='barry'";

Delete SQL

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<body><?php


//define connection string, specify database driver$connStr = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\mbsebus\CHeavin\Databases\

cus.accdb";


$sql="DELETE * FROM test WHERE name='Ciara'";echo "Connection Open<br>";$rS = $conn->execute($sql); print "Record Deleted";$conn->Close(); ?>

</body>

</html>

Delete Records

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$sql="INSERT INTO test (name,age) VALUES ('".$name1."','".$age1."' );";

//Set SQL query

Insert SQL

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<body><?php//create an instance of the ADO connection object$conn = new COM ("ADODB.Connection") or die("Cannot start ADO");

//define connection string, specify database driver$connStr="PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\mbsebus\CHeavin\



echo "Connection Open<br>";$name1="barack obama";$age1="32";

$sql="INSERT INTO test (name,age) VALUES ('".$name1."','".$age1."' );"; //Set SQL query

$conn->Execute($sql); //Execute SQL query print "Record Inserted";$conn->Close(); //Close database connection ?>

</body>

</html>

Insert Records

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<html>

<head><title>Join</title></head>

<body>

<FORM METHOD="POST" ACTION="memberadded.php">

Name:<INPUT TYPE="text" SIZE="40" name="cust_name"><br>

Age:<INPUT TYPE="text" SIZE="40" name="cust_age"><br>

<input type="submit" value="Proceed"></form> </body></html>

Add Record through Form

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<body><html><head><title>New User</title></head><body><br/> Name:<?php echo($_POST['cust_name']); ?><br/> Age:<?php echo($_POST['cust_age']); ?><br/> <?php//create an instance of the ADO connection object$conn = new COM ("ADODB.Connection") or die("Cannot start ADO");

//define connection string, specify database driver$connStr="PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Inetpub\wwwroot\mbsebus\CHeavin\Databases\cus.accdb";//Open the connection to the database $conn->open($connStr); $name=$_POST['cust_name'];$age=$_POST['cust_age']; $sql="INSERT INTO test (name,age) VALUES ('".$name."','".$age."' );"; //Set SQL query

$conn->Execute($sql); //Execute SQL query

$conn->Close(); //Close database connection ?> </body></html>

</body>

</html>

memberadded.php

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Database 20/2/12 Connection