Beginners Guide to Web-Enabling your Informix database Using : By: Peter Schmidt PRS Technologies, Inc

Beginners Guide to Beginners Guide to Web-Enabling your Web-Enabling your Informix databaseInformix database

UsingUsing::

By: By: Peter SchmidtPeter Schmidt

PRSPRS Technologies, Inc.Technologies, Inc.

October, 2000 2PRSTechnologies, Inc.

What is PHP ?What is PHP ?

PHP (officially "PHP: Hypertext Preprocessor")• ( Originally “Personal Home Page” )

• A server-side HTML-embedded scripting language.

• Writing a database-enabled web page is incredibly simple !

• PHP is in use on over 150,000 sites around the world.

• Since PHP is executed on the web server, web browsers can’t see your PHP code.

• PHP is very fast.

• PHP is completely free (Open Source)

PHP (officially "PHP: Hypertext Preprocessor")• ( Originally “Personal Home Page” )

• A server-side HTML-embedded scripting language.

• Writing a database-enabled web page is incredibly simple !

• PHP is in use on over 150,000 sites around the world.

• Since PHP is executed on the web server, web browsers can’t see your PHP code.

• PHP is very fast.

• PHP is completely free (Open Source)


The following databases are currently supported:The following databases are currently supported:

• Informix InterBase PostgreSQL

• dBase FrontBase Solid

• Empress mSQL Sybase

• FilePro (read-only) Direct MS-SQL Unix dbm

• IBM DB2 MySQL Adabas D

• ODBC Velocis Ingres

• Oracle (OCI7 and OCI8)

• Informix InterBase PostgreSQL

• dBase FrontBase Solid

• Empress mSQL Sybase

• FilePro (read-only) Direct MS-SQL Unix dbm

• IBM DB2 MySQL Adabas D

• ODBC Velocis Ingres

• Oracle (OCI7 and OCI8)


An introductory example of PHPAn introductory example of PHP

<html>

<body> <?php echo "Hi, I'm a PHP script!"; ?> </body>

</html>

Note that PHP code is embedded inside the HTML code.

Demo 1


<html><body>

Here I am in HTML! <BR>

<?php echo ”Now I'm in PHP! <BR>"; ?>

Back to HTML! <BR>

</body></html>

HTML

PHP

Back to HTML

Note the PHP start and stop tags

Demo 2

PHP code is executed on the web server!

Switching between HTML and PHPSwitching between HTML and PHP


Putting comments in PHP codePutting comments in PHP code

<?php

echo "This is a test <br>"; // This is a one-line c++ style comment

echo "This is a test <br>"; # This is Unix shell-style style comment

/* This is the first line of a multi line comment This is the second line of comment */

?>

PHP supports 'C', 'C++' and Unix shell-style comments.


Connecting to the Informix databaseConnecting to the Informix database<?php

$database = "video"; /* populate variables */$server = "lapdog_tcp";$login = ”username";$password = ”password";

$dbs = $database . "@" . $server; /* concatenate */

$connect_id = ifx_pconnect($dbs,$g_login,$g_password);

if (!$connect_id) {echo "Unable to connect to Informix database<br>\n";chk_ifx_err1($connect_id);

} else {echo “Informix connection successful! <br>”;

}

?>

Demo 3

This is my user defined function


<?php

$database = "video";$server = "lapdog_tcp";$login = ”username";$password = ”password";

?>

Demo 3

Use a tcp/ip connection to the database

(vs. a shared memory connection)

Warning: E [SQLSTATE=IX 000 SQLCODE=-27000] in /u/www/lapdog/php_demo/php_demo4.php3 on line 40Unable to connect to Informix database

Informix error: Cannot support multiple connections over shared memory.

finderr -27000-27000 Cannot support multiple connections over shared memory.

An application cannot use the CONNECT statement to make more than one connection that uses shared-memory communication (IPC).

Ensure that the application makes only one shared-memory connection at a time. If the application must use concurrent connections, the database server administrator might need to change the connection type(as specified in the nettype field of the sqlhosts file) from a shared -memory connection to a network connection.

Use a tcp/ip connection to avoid error -27000Use a tcp/ip connection to avoid error -27000


Persistent database connectionsPersistent database connections

• An SQL connection that does not close when the execution of your script ends.

• When a persistent connection is requested, PHP checks if there's already an identical persistent connection (that remained open from earlier) - and if it exists, it uses it.

• If it does not exist, it creates the connection.

• if connection overhead is high, persistent connections help you considerably.

• It may (and probably will) change the efficiency of the script, but should not change its behavior!

• An SQL connection that does not close when the execution of your script ends.

• When a persistent connection is requested, PHP checks if there's already an identical persistent connection (that remained open from earlier) - and if it exists, it uses it.

• If it does not exist, it creates the connection.

• if connection overhead is high, persistent connections help you considerably.

• It may (and probably will) change the efficiency of the script, but should not change its behavior!

$connect_id = ifx_pconnect();


<?php

function chk_ifx_err1($result_id) {

$err_string = ifx_error($result_id);

/* Note: error If 1st character of err_string is not blank */

if ($err_string[0] != ' ') {printf("Informix error: %s", ifx_errormsg());die;

}}

?>

Warning: E [SQLSTATE=IX 000 SQLCODE=-952]

in /u/www/lapdog/php_demo/php_demo4.php3 on line 40Unable to connect to Informix database

Informix error: User's password is not correct for the database server.

Demo 4

Get the error string

Check for blank

User defined function

End program

Reporting an Informix errorReporting an Informix error


<?php

if ($connect_id) {

$statmt_txt = "select count(*) count from vhs where type_code = 'ST1' ";

$statmt_id1 = ifx_query($statmt_txt,$connect_id); // EXECUTE SQL

if (!$statmt_id1) { chk_ifx_err1($statmt_id1); } // CHECK FOR ERROR

$row = ifx_fetch_row($statmt_id1); // FETCH RESULT OF COUNT INTO ARRAY

if (!$row) { chk_ifx_err1($statmt_id1); } // CHECK FOR ERROR

$num_rows_selected = sprintf("%d",$row[count]); // FORMAT COUNT

echo "<html>"; echo "$num_rows_selected rows selected <BR>"; // DISPLAY RESULT IN HTML echo "</html>";}

?>

Demo 5

Selecting a count from a tableSelecting a count from a table


<?php

$statmt_txt = "select tape_num Tape_Number ,title from vhs where type_code = 'ST1' order by title";

$statmt_id = ifx_prepare($statmt_txt,$connect_id,IFX_SCROLL); // PREPARE

if (!$statmt_id) { chk_ifx_err1($statmt_id); } // CHECK FOR ERROR

$ret_val = ifx_do($statmt_id); // EXECUTE PREPARED STATEMENT

if (!$ret_val) { chk_ifx_err1($statmt_id); } // CHECK FOR ERROR

ifx_htmltbl_result ($statmt_id, "BORDER='1' CELLSPACING=0 CELLPADDING=2 BGCOLOR='cornsilk' ALIGN=center");

?>

Demo 6

See output on next slide

Use display label for clarity

Selecting rows Output to a HTML table.

Selecting rows Output to a HTML table.


Result from using: ifx_htmltbl_result Result from using: ifx_htmltbl_result

Tape_number Title

1 A Piece of the Action

9 A Taste of Armageddon

10 Amok Time

2 And The Children Shall Lead

8 Arena

Demo 6


<?php

$statmt_txt = "select * from vhs where type_code = 'ST1' order by title";

$statmt_id = ifx_prepare($statmt_txt,$connect_id,IFX_SCROLL); // PREPARE

if (!$statmt_id) { chk_ifx_err1($statmt_id); } // CHECK FOR ERROR

$ret_val = ifx_do($statmt_id); // EXECUTE PREPARED STATEMENT


echo <table border=5 cellspacing=0 cellpadding=5 bgcolor=cornsilk>”; // HTML

Demo 7

--- Continued on next slide ---

Selecting rows using a cursorslide 1 of 2



while ($row = ifx_fetch_row($statmt_id, ”NEXT” )) {

$serial_id = $row[serial_id];$type_code = chop($row[type_code]);$tape_num = $row[tape_num];$title = chop($row[title]);$hours = $row[hours];$comment = chop($row[comment]);

echo "<tr>\n";echo "<td><center>$serial_id</td>";echo "<td><center>$type_code</td>";echo "<td><center>$tape_num</td>";echo "<td>$title</td>";echo "<td>$hours</td>";echo "<td>$comment</td>";

echo "<td>";}

echo "</table>";?>

Demo 7

--- Continued from previous slide ---

Create an “associative” arraynamed “row”.

Use column namesto identify fields.

Use “chop” to remove trailing blanks if desired.

Populate fields from associative array




<?php

$statmt_txt = "select * from vhs where type_code = ? order by title";

?>

Demo 7

“placeholders” are currently not supported, but you can do this instead.

<?php

$my_code = “ST1”;

$statmt_txt = "select * from vhs where type_code = ’ $my_code ' order by title";

?>

Invalid statement

valid statement

Can’t use placeholdersCan’t use placeholders


<html>

<form action="video_db2.php3" method="post"> Tape Number:

<input type="text" name=”tape_num"> <input type="submit"></form>

</html>

<?php

echo “The tape number is: $tape_num <br>”;

?>

Variables from outside PHPHTML Forms (GET and POST)

Variables from outside PHPHTML Forms (GET and POST)


<?php

if ($connect_id) {

$sql_txt = "insert into vhs (serial_id, type_code, tape_num, title) values "; $sql_txt .= ” ($serial_id, \”$type_code\”, $tape_num, \”$title\”) ";

$ret_val = ifx_query($sql_txt,$connect_id); // INSERT RECORD


}

?>

Inserting a rowInserting a row


<?php

$input_array = array ( "type_code" => $type_code, "tape_num" => $tape_num, "title" => $title, "hours" => $hours, "comment" => $comment);

?>

An associative array is an array which uses a string (instead of a number) to locate an element within the array.

Creating an associative arrayCreating an associative array


<?php$type_code_array = array ( "MOVIE" => "Movies", "DS9" => "Deep Space 9", "ST1" => "Star Trek (Original)", "ST2" => "Star Trek the Next Generation", "VOY" => "Star Trek Voyager", "HOME" => "Home Movies", "MAX" => "Max Headroom", "OTHER" => "Other");

echo “<select name='type_code'> <option value=' '>Choose Type of Video”;

while (list($key,$value) = each($type_code_array)) {

if ($key == $type_code) { echo "<option value='$key' selected>$value\n"; } else { echo "<option value='$key'>$value\n"; }}echo "</select>”;?>

Create an associative array of type codes

Step through the array

Stepping through an associative arrayStepping through an associative array


<?php

if (preg_match("/\|/",$query_string)) { // Search $query_string for a pipe

… your code here … // Do this if pipe was found

}

?>

Search a string for the presence of a pipe symbol

• Perform a regular expression match on a string.

• Return (true) if match was positive.

• The syntax for the pattern search closely resembles Perl.

• Perform a regular expression match on a string.

• Return (true) if match was positive.

• The syntax for the pattern search closely resembles Perl.

Searching a string for a pattern Perl-compatible Regular Expression functions

Searching a string for a pattern Perl-compatible Regular Expression functions


<?php

$query_string = “ 123 | 456 | 789 “;

$pipe_list = preg_split("/\|/",$query_string); // Create an array of strings

while ( list($key,$value) = each($pipe_list)) { // for each element in the array...

… your code here …

?>

Create an array from pipe demimited string

• Split string by a regular expression.

• Returns an array containing substrings.

• The syntax closely resembles Perl.

• Split string by a regular expression.

• Returns an array containing substrings.

• The syntax closely resembles Perl.

Creating an array from a pipe-delimited string

Perl-compatible Regular Expression functions

Creating an array from a pipe-delimited string

Perl-compatible Regular Expression functions


<?php

function cnt_and_query ($table_name,$where_clause) {

… more php code here …

return array ($statmt_id2,$num_rows_selected);

}

?>

<?php

list($statmt_id,$cnt_found) = cnt_and_query("vhs",$where_clause);

?>

Call a function

Start function

End function

Return multiple values

Call a functionpassing and returning variables

Call a functionpassing and returning variables


<?phprequire("common.inc");require("menu.inc");require("display_form.inc");require("query.inc");require("add.inc");require("modify.inc");

?>

• Use include() and require() to reference program modules.

• With include, statements are re-evaluated each time - almost like calling a function.

• With require, statements are replaced by the required file when it is first encountered. Good for user defined functions.

• Use include() and require() to reference program modules.

• With include, statements are re-evaluated each time - almost like calling a function.

• With require, statements are replaced by the required file when it is first encountered. Good for user defined functions.

Breaking your program up into logical modules

Breaking your program up into logical modules


Scope of variablesScope of variables• Scope spans the entire module, including “included” and

“required” files.

• Variables defined outside of a function, can be referenced inside the function, if defined as globally available.

• Any variable defined inside a function can only be used within that function, unless specifically defined as globally available in that function.

• Globals can also be accessed via the special “GLOBALS” array.

• See “demo8” for examples.

• Scope spans the entire module, including “included” and “required” files.

• Variables defined outside of a function, can be referenced inside the function, if defined as globally available.

• Any variable defined inside a function can only be used within that function, unless specifically defined as globally available in that function.

• Globals can also be accessed via the special “GLOBALS” array.

• See “demo8” for examples.

Demo 8

global $variable5;

$dbs = $GLOBALS["DATABASE"];


Installing PHPInstalling PHP• PHP (without Informix) is usually available on most Linux and

Apache installations using ODBC.

• Configuring PHP to use Informix is NOT a cakewalk.• Requires use of ESQL/C libraries to compile (free w/Client SDK).

• Don’t reuse previous versions of Apache httpd.conf if you are upgrading Apache from a earlier version.

• If you want the database to reside in a machine separate from the web server, you will need Informix Client SDK or I-Connect on the web server.

• If you're using I-Connect on the deployment machine, you must compile on a machine with ClientSDK installed. And CSDK and I-Connect need to be in the same directory on the two different machines.

• PHP (without Informix) is usually available on most Linux and Apache installations using ODBC.

• Configuring PHP to use Informix is NOT a cakewalk.• Requires use of ESQL/C libraries to compile (free w/Client SDK).

• Don’t reuse previous versions of Apache httpd.conf if you are upgrading Apache from a earlier version.

• If you want the database to reside in a machine separate from the web server, you will need Informix Client SDK or I-Connect on the web server.

• If you're using I-Connect on the deployment machine, you must compile on a machine with ClientSDK installed. And CSDK and I-Connect need to be in the same directory on the two different machines.


• Aquire or download the software.

• Unpack Apache and PHP tar-balls.

• Set your Informix environmentals.

• Pre-Configure Apache.

• Configure, compile and install PHP

• Configure, compile and install Apache.

• Update Apache startup script with Informix environment

• Update Apache httpd.conf

• Re-start Apache web server.

• Test.

• Aquire or download the software.

• Unpack Apache and PHP tar-balls.

• Set your Informix environmentals.

• Pre-Configure Apache.

• Configure, compile and install PHP

• Configure, compile and install Apache.

• Update Apache startup script with Informix environment

• Update Apache httpd.conf

• Re-start Apache web server.

• Test.

Installing PHP with ApacheOverview

Installing PHP with ApacheOverview


• Go to http://www.php.net

• Click on: downloads

• Click on: Complete Source Code• PHP 4.0.2 - 29 August 2000

• Go to http://www.apache.org

• Click on apache server.

• Click on download.

• Click on apache_1.3.14.tar.gz

• Go to http://www.php.net

• Click on: downloads

• Click on: Complete Source Code• PHP 4.0.2 - 29 August 2000

• Go to http://www.apache.org

• Click on apache server.

• Click on download.

• Click on apache_1.3.14.tar.gz

Installing PHP with ApacheAquire or download the software

Installing PHP with ApacheAquire or download the software


cd /usr/local

gunzip apache_1.3.14.tar.gz

tar xvf apache_1.3.14.tar

gunzip php-4.0.2.tar.gz

tar xvf php-4.0.2.tar

Installing PHP with Apache Unpack Apache and PHP tar-balls

Installing PHP with Apache Unpack Apache and PHP tar-balls


INFORMIXDIR=/opt/informixINFORMIXSERVER=myserver_shmONCONFIG=onconfig.myserverPATH=$PATH:$INFORMIXDIR/binLD_LIBRARY_PATH=$INFORMIXDIR/lib:$INFORMIXDIR/lib/esql

export INFORMIXDIR INFORMIXSERVER ONCONFIG LD_LIBRARY_PATH

Don’t forget this one!

Installing PHP with Apache Set your Informix environmentals

Installing PHP with Apache Set your Informix environmentals

Optional


cd apache_1.3.14

./configure --prefix=/usr/local/apache

cd ..

Installing PHP with Apache Pre-Configure Apache

Installing PHP with Apache Pre-Configure Apache


cd php-4.0.2

./configure --with-apache=../apache_1.3.14 --with-informix=$INFORMIXDIR

make

make install

cd ..

Installing PHP with Apache Configure, compile and install PHP

Installing PHP with Apache Configure, compile and install PHP


cd apache_1.3.14

./configure --prefix=/usr/local/apache \

--enable-module=rewrite \

--enable-shared=rewrite \

--enable-module=most \

--enable-shared=max \

--enable-module=so \

--activate-module=src/modules/php4/libphp4.a \

--enable-module=php4

make

make install

cd ..

Installing PHP with Apache Configure, compile and install Apache

Installing PHP with Apache Configure, compile and install Apache


cd /etc/rc.d/init.d

• On Linux, update the apache start-up script “httpd” to include the Informix environment.

• Or use apachectl. (Varies by platform.)

• On Linux, update the apache start-up script “httpd” to include the Informix environment.

• Or use apachectl. (Varies by platform.)

Installing PHP with Apache Update Apache startup script with Informix environment

Installing PHP with Apache Update Apache startup script with Informix environment


cd /usr/local/apache/conf

• Update the apache configuration file “httpd.conf”.

• If you have upgraded Apache from a different version, do not use the previous “httpd.conf” file as a basis for the new one.

• Update the apache configuration file “httpd.conf”.

• If you have upgraded Apache from a different version, do not use the previous “httpd.conf” file as a basis for the new one.

AddModule mod_php4.c

<IfModule mod_php4.c>

AddType application/x-httpd-php4 .php4

AddType application/x-httpd-php4-source .phps

</IfModule>

Installing PHP with Apache Update Apache httpd.conf

Installing PHP with Apache Update Apache httpd.conf


cd /etc/rc.d/init.d

./httpd restart

Installing PHP with Apache Re-start Apache web server

Installing PHP with Apache Re-start Apache web server

apachectl

apachectl configtest

Also, you can use:

On Linux:


• http://www.prstech.com (downloads section)

• This presentation• Entire source of videotape demo• Source of all examples• Tech-Notes article on PHP by Mario Estrada• Monterey Peninsula Ski Club - Cabin Reservation System by

Jonathan Leffler

• http://www.php.net

• http://www.zend.com

• http://www.prstech.com (downloads section)

• This presentation• Entire source of videotape demo• Source of all examples• Tech-Notes article on PHP by Mario Estrada• Monterey Peninsula Ski Club - Cabin Reservation System by

Jonathan Leffler

• http://www.php.net

• http://www.zend.com

PHP ResourcesPHP Resources

PRSPRS Technologies, Technologies, Inc.Inc.

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Beginners Guide to Web-Enabling your Informix database Using : By: Peter Schmidt PRS Technologies, Inc