YA: Search An Entire MySQL Database 20120715232139AAL4jEE

<?php

session_start(); // Will be using sessions for minor caching; increasing performance/speed

/*    Functions    */
function db_connect(){
    Global $conn;
    $conn = mysql_connect('localhost','root','') or die('Cannot Connect To MySQL Server because: ' . mysql_error());
}
function db_select_db($dbname){
    Global $conn;
    mysql_select_db($dbname, $conn) or die('Cannot Select database "' .$dbname . '" because: ' . mysql_error($conn));
}
function db_tables($dbname){
    if( isset($_SESSION['dbs'][$dbname]['__tables'])){ // Retrieve From Cache if exists
        return $_SESSION['dbs'][$dbname]['__tables'];
    }
    Global $conn;
    $dbname = mysql_real_escape_string($dbname);
    $stmt = "SHOW TABLES FROM " . $dbname;
    $r = mysql_query($stmt, $conn) or die('Query [' . $stmt . '] failed because: ' . mysql_error($conn));
    $tables = Array();
    while($row = mysql_fetch_array($r)){
        $tables[] = $row[0];
    }
    if( isset($_SESSION['dbs'][$dbname])){
        $_SESSION['dbs'][$dbname]['__tables'] = $tables;
    }
    return $tables;
}
function db_columns($dbname, $tblname){
    if( isset($_SESSION['dbs'][$dbname]['__columns'][$tblname])){
        return $_SESSION['dbs'][$dbname]['__columns'][$tblname];
    }
    Global $conn;
    $dbname = mysql_real_escape_string($dbname);
    $tblname = mysql_real_escape_string($tblname);
    $stmt = "SHOW COLUMNS FROM {$dbname}.{$tblname}";
    $r = mysql_query($stmt, $conn) or die('Query [' . $stmt . '] failed because: ' . mysql_error($conn));
    $columns = Array();
    while($row = mysql_fetch_row($r)){
        $columns[] = $row[0];
    }
    if( isset($_SESSION['dbs'][$dbname])){
        $_SESSION['dbs'][$dbname]['__columns'][$tblname] = $columns;
    }
    return $columns;
}
function db_databases(){
    if( isset($_SESSION['dbs']) && is_array($_SESSION['dbs']) && count($_SESSION['dbs']) > 0){ // Retrieve From Cache if exists
        return array_keys($_SESSION['dbs']);
    }
    Global $conn;
    $stmt = "SHOW DATABASES";
    $r = mysql_query($stmt, $conn) or die('Query [' . $stmt . '] failed because: ' . mysql_error($conn));
    $dbs = Array();
    while($row = mysql_fetch_array($r)){
        $dbs[$row[0]] = Array();
    }
    $_SESSION['dbs'] = $dbs;
    return array_keys($dbs);
}
if( isset( $_POST['submit'] )){

}
function load_db_structure($dbname){
    if( isset($_SESSION['dbs'][$dbname]) ){
        return $_SESSION['dbs'][$dbname];
    }
    db_connect();
    foreach(db_tables($dbname) as $tbl){
        db_columns($dbname, $tbl);
    }
    return $_SESSION['dbs'][$dbname];
}

function results_to_table($results, $dbname, $tbl){
    $table = '<table cellspacing="1" border="1" style="width: 100%">';
    $columns =  db_columns($dbname, $tbl);
    $colCount = count($columns);
    $table .= '    <tr>
        <td colspan="' . $colCount . '"><span style="font-style: italic;">' . $dbname . '</span>.<span style="font-weight: bold;font-size: 130%">' . $tbl . '</span></td>
    </tr>' . PHP_EOL;
    $table .= '    <tr>' . PHP_EOL;
    foreach ($columns as $col){
        $table .= '        <th>' . $col . '</th>' . PHP_EOL;
    }
    $table .= '    </tr>' . PHP_EOL;
    while($row = mysql_fetch_row($results)){
        $table .= '    <tr>' . PHP_EOL;
        foreach($row as $val){
            $table .= '        <td>' . $val . '</td>' . PHP_EOL;
        }
        $table .= '    </tr>' . PHP_EOL;
    }
    $table .= '</table><br><br>' . PHP_EOL;
    return $table;
}


/*    Processing    */

$search = (isset($_POST['search']))? trim($_POST['search']) : '';

if( strlen($search) > 0){
    db_connect();
    $search = mysql_real_escape_string($search);
    $dbname = $_POST['pmo'];
    load_db_structure($dbname);
    $tables = db_tables($dbname);
    $results = '';
    foreach($tables as $tbl){
        $columns = db_columns($dbname, $tbl);
        $stmt = "SELECT * FROM {$dbname}.{$tbl} WHERE ";
        $i =0;
        foreach($columns as $col){
            if( $i++ > 0){
                $stmt .= ' OR ';
            }
            $stmt .= $col . " LIKE '%" . $search . "%'";
        }
        $r = mysql_query($stmt, $conn) or die('Query [' . $stmt . '] failed because: ' . mysql_error($conn));
        if( mysql_num_rows($r) > 0){
            $results .= results_to_table($r, $dbname, $tbl);
        }
    }
    if( strlen( $results ) > 0){
        echo '<h2>Results for "' . $search . '"</h2>' . PHP_EOL;
        echo $results;
    }else{
        echo '<h2>No Results Found for "' . $search . '"</h2>' . PHP_EOL;
        $search = '';
    }
}
echo '<form method="post">
    <input type="text" name="search" value="' . $search . '">';
echo '<select name="pmo">';
db_connect();
foreach(db_databases() as $dbname){
    echo '<option value="' . $dbname . '">' . $dbname . '</option>';
}

echo '
    <input type="submit" value="Search">
</form>';