An ORACLE paging program, very practical._PHP tutorial

// 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 "

";
echo "";
echo "";
echo "";
echo "";
echo "";
echo "";
echo "";

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($rs)){
        echo "";
        for ($i = 1; $i < ($num_columns + 1); $i++) {
            $column_value = OCIResult($rs,$i);
            echo "";
        }
        echo "";
    }

} else {

    // Print a message stating that no records was found
    echo "";
}

// Close the table
echo "

PK ID	Field 1	Field 2	Field 3	Row No
$column_value
Sorry! No records was found

";

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

?>


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

echo "

Total pages: ".$total_pages."

";
echo "

Number of records: ".$num_rows."

";
echo "

The SQL Query is: ".$sql."

";

?>