MySQL Database Handling in PHP

Written by John L

Continued from page 1

The @ operator is used to suppress any error messages that mysql_connect() and mysql_select_db() functions may produce if an error occurred. The die() function is used to endrepparttar script execution and display a custom error message.

Executing SQL Statements against a MySQL database

Oncerepparttar 105568 connection and database selection is successfully performed,repparttar 105569 PHP script can now proceed to operate onrepparttar 105570 database using standard SQL statements. The mysql_query() function is used for executing standard SQL statements againstrepparttar 105571 database. Inrepparttar 105572 following example,repparttar 105573 PHP script queries a table called tbl_login inrepparttar 105574 previously selected database to determine if a username/password pair provided byrepparttar 105575 user is valid.

Assumption: The tbl_login table has 3 columns named login, password, last_logged_in. The last_logged_in column storesrepparttar 105576 time thatrepparttar 105577 user last logged intorepparttar 105578 system.

// The $username and $passwd variable should rightly be set byrepparttar 105579 login form // throughrepparttar 105580 POST method. Forrepparttar 105581 purpose of this example, we’re manually coding it. $username = “john”; $passwd = “mypassword”;

// We generate a SELECT SQL statement for execution. $sql="SELECT * FROM tbl_login WHERE login = '".$username."' AND password = '".$passwd."'";

// Executerepparttar 105582 SQL statement againstrepparttar 105583 currently selected database. // The results will be stored inrepparttar 105584 $r variable. $r = mysql_query($sql);

// Afterrepparttar 105585 mysql_query() command executes,repparttar 105586 $r variable is examined to // determine ofrepparttar 105587 mysql_query() was successfully executed. if(!$r) { $err=mysql_error(); print $err; exit(); }

// If everything went well, check ifrepparttar 105588 query returned a result – i.e. ifrepparttar 105589 username/password // pair was found inrepparttar 105590 database. The mysql_affected_rows() function is used for this purpose. // mysql_affected_rows() will returnrepparttar 105591 number of rows inrepparttar 105592 database table that was affected // byrepparttar 105593 last query if(mysql_affected_rows()==0){ print "Username/password pair is invalid. Please try again."; } else {

// If successful, read outrepparttar 105594 last logged in time into a $last variable for display torepparttar 105595 user $row=mysql_fetch_array($r); $last=$row["last_logged_in"]; print “Login successful. You last logged in at ”.$last.”.”;


The above example demonstrated how a SELECT SQL statement is executed againstrepparttar 105596 selected database. The same method is used to execute other SQL statements (e.g. UPDATE, INSERT, DELETE, etc.) againstrepparttar 105597 database usingrepparttar 105598 mysql_query() and mysql_affected_rows() functions.

This PHP scripting article is written by John L. John L is the Webmaster of The Ultimate BMW Blog! (

The Ultimate BMW Blog!

XML Promises and challenges

Written by Ror Sabo

Continued from page 1

Microsoft XML Validation Tool checks that an XML file is well formed.

XML Spy is a powerful XML editor.

XMetaL is an advanced, simple-to-deploy XML authoring tool that delivers an unprecedented ease of use.

More XML Tools >>

XML Free Tutorial: A lot of free tutorial can be found on different ways XML can be used.

2-XML Syntax

   The simple and very strict syntax rules of XML.

3-XML Elements

   XML Elements, relationships, content and naming rules.

4-XML Attributes

   How XML attributes can be used to describe elements, or to provide additional information about


5-XML Validation

   The difference between a Well Formed and a Valid XML document and how a DTD is used to define

   the XML document.

6-XML support in Netscape and Explorer

   Aboutrepparttar 105567 support for XML inrepparttar 105568 two most famous browsers.

7-Viewing XML in Internet Explorer

   How to use Internet Explorer to view an XML file.

8-Displaying XML with CSS

   How to use Internet Explorer and CSS to display an XML file.

9-Displaying XML with XSL

   How to use Internet Explorer and XSL to display an XML file.

10-XML embedded in HTML

   How to embed XML inside HTML documents.

11-The Microsoft XML Parser

   How to userepparttar 105569 Microsoft XML parser to open and manipulate XML documents.

12-XML in Real Life

   This is where we take a look at some real life use of XML.

13-XML Namespaces

   How to avoid element name conflicts using XML namespaces.


   How to tell an XML parser not to parserepparttar 105570 text.

15-XML Encoding

   How to encode your XML documents.

16-XML Server

   How to generate XML onrepparttar 105571 server.

17-XML Applications

   How you can use IE to navigate an XML file and how to create a complete XML application.

18-XML HTTP Requests

   How to request XML from a server using HTTP.

19-Behaviors for HTML and XML

   Howrepparttar 105572 new CSS behavior selector can be used to create dynamic content.

20-XML Technologies

   XML technologies that are important torepparttar 105573 understanding and development of XML applications. Your free online Resources for software and Hardware Drivers in addition to Free online tutorial

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