PHPBuilder - How to split the result into pages, like 'limits' in MySQL?



RSS Twitter
Snippets Databases

How to split the result into pages, like 'limits' in MySQL?

by: Neil Craig
|
June 5, 2001

Version: 1.0

Type: Sample Code (HOWTO)

Category: Databases

License: Other

Description: Ever wanted to split the results from your ORACLE query into pages, like the 'LIMIT' functions on MySQL. Well, in this tutorial I explain just how to do that with out sacrificing ordering the results. I also explain the queries in detail.



<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>Paging Test</TITLE>
<META NAME="Generator" CONTENT="TextPad 4.0">
<META NAME="Author" CONTENT="?">
<META NAME="Keywords" CONTENT="?">
<META NAME="Description" CONTENT="?">
</HEAD>

<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#FF0000" VLINK="#800000" ALINK="#FF00FF" BACKGROUND="?">
<?php

// How to split the result into pages, like 'limits' in MySQL?
// ===========================================================
// Tutorial by Neil Craig (neilc@netactive.co.za)
// Date: 2001-06-05
// With this example, I will explain paging of database queries where the
// result is more than the developer want to print to the page, but wish to 
// split the result into seperate pages.
// The table "SAMPLE_TABLE" accessed in this tutorial has 4 fields:
// PK_ID, FIELD1, FIELD2 and FIELD3. The types don't matter but you should
// define a primary key on the PK_ID field.

$display_rows = 5;     // The rows that should be display at a time. You can
                       // modify this if you like.

// Connect to the Oracle database
putenv("ORACLE_SID=purk");
putenv("ORACLE_HOME=/export/oracle8i");
putenv("TNS_ADMIN=$ORACLE_HOME/network/admin");
$OracleDBConn = OCILogon("purk","purk","lengana.world");

// This query counts the records
$sql_count = "SELECT COUNT(*) FROM SAMPLE_TABLE";

// Parse the SQL string & execute it
$row_count=OCIParse($OracleDBConn, $sql_count);       
OCIExecute($row_count);

// From the parsed & executed query, we get the amount of records found.
// I'm not storing this result into a session variable because it allows for
// new records to be shown as it is entered by another user while the result
// is printed.
if (OCIFetch($row_count)) {
	$num_rows = OCIResult($row_count,1);
} else {
	$num_rows = 0;        // If no record was found
}

// Free the resources that were used for this query
OCIFreeStatement($row_count);

// We need to prepare the query that will print the results as a page. I will 
// explain the query to you in detail.

// If no page was specified in the url (ex. http://mysite.com/result.php?page=2),
// set it to page 1.
if (empty($page) || $page == 0) {
	$page = 1;
}

// The start range from where the results should be printed
$start_range = (($page - 1) * $display_rows) + 1;

// The end range to where the results should be printed
$end_range = $page * $display_rows;

// The main query. It consists of 3 "SELECT" statements nested into each
// other. The center query is the query you would normally use to return the
// records you want. Do you ordering and "WHERE" clauses in this statement.
// We select the rows to limit our results but because the row numbers are
// assigned to the rows before any ordering is done, lets the code print the
// result unsorted.
// The second nested "SELECTED" assigns the new row numbers to the result
// for us to select from.

$sql = "SELECT PK_ID, FIELD1, FIELD2, FIELD3, ROW_NO FROM (SELECT PK_ID, ";
$sql .= "FIELD1, FIELD2, FIELD3, ROWNUM ROW_NO FROM (SELECT PK_ID, FIELD1, ";
$sql .= "FIELD2, FIELD3 FROM SAMPLE_TABLE ORDER BY FIELD3)) WHERE ROW_NO BETWEEN ";
$sql .= $start_range." AND ".$end_range;

// start results formatting
echo "<table width='95%' border='1' cellspacing='1' cellpadding='2' align='center'>";
echo "<tr bgcolor='#666666'>"; 
echo "<td><b><font color='#FFFFFF'>PK ID</font></b></td>";
echo "<td><b><font color='#FFFFFF'>Field 1</font></b></td>";
echo "<td><b><font color='#FFFFFF'>Field 2</font></b></td>";
echo "<td><b><font color='#FFFFFF'>Field 3</font></b></td>";
echo "<td><b><font color='#FFFFFF'>Row No</font></b></td>";
echo "</tr>";

if ($num_rows != 0) {

	// Parse the SQL string & execute it
	$rs=OCIParse($OracleDBConn, $sql);       
	OCIExecute($rs);
	
	// get number of columns for use later
	$num_columns = OCINumCols($rs);
	
	while (OCIFetch($rs)){
		echo "<tr>";
		for ($i = 1; $i < ($num_columns + 1); $i++) {
			$column_value = OCIResult($rs,$i);
			echo "<TD>$column_value</TD>";
		}
		echo "</tr>";
	}
		
} else {

	// Print a message stating that no records was found
	echo "<tr><td align=center>Sorry! No records was found</td></tr>";
}

// Close the table
echo "</TABLE>";

// free resources and close connection
OCIFreeStatement($rs);
OCILogoff($OracleDBConn);

?>
<div align=center>
<?php

// Here we will print the links to the other pages

// Calculating the amount of pages
if ($num_rows % $display_rows == 0) {
	$total_pages = $num_rows / $display_rows;
} else {
	$total_pages = ($num_rows / $display_rows) + 1;
	settype($total_pages, integer); // Rounding the variable
}

// If this is not the first page print a link to the previous page
if ($page != 1) {
	echo "<a href='".$PHP_SELF."?page=".($page - 1)."'>Previous</a>";
}

// Now we can print the links to the other pages
for ($i = 1; $i <= $total_pages;  $i++) {
	if ($page == $i){
		// Don't print the link to the current page
		echo " ".$i;
	} else {
		//Print the links to the other pages
		echo " <a href='".$PHP_SELF."?page=".$i."'>".$i."</a>";
	}
}

// If this is not the last page print a link to the next page
if ($page < $total_pages) {
	echo " <a href='".$PHP_SELF."?page=".($page + 1)."'>Next</a>";
}

?>
</div>
<?php

// I'm just adding this section to print some of the variables for extra info
// and some debugging

echo "<p><b>Total pages: </b>".$total_pages."</p>";
echo "<p><b>Number of records: </b>".$num_rows."</p>";
echo "<p><b>The SQL Query is:</b> ".$sql."</p>";

?>
</BODY>
</HTML>

Comment and Contribute

Your comment has been submitted and is pending approval.

Author:
Neil Craig

Comment:



Comment:

(Maximum characters: 1200). You have characters left.