Lihtsaid php ja mysql näiteid

Allpool on näited kasutajana fstudent ja andmebaasiga facebook, 2011 praksis kasuta userit rstudent ja andmebaasi reddit, samuti tee oma tabelid.

Hello world php-s: http://dijkstra.cs.ttu.ee/~tammet/k1.php

Algus.<p>

<?php echo '<p>Hello World</p>'; ?> 

<p>Lopp.

Nii saab uurida PHP settungeid, praksis see otseselt oluline ei ole: http://dijkstra.cs.ttu.ee/~tammet/k2.php

Algus.<p>

<?php 

echo '<p>calling phpinfo():</p>'; 
phpinfo();

?> 

<p>Lopp.

Esimene andmebaasipäring: http://dijkstra.cs.ttu.ee/~tammet/k3.php

Algus.<p>


<?php
$con = mysql_connect("localhost","fstudent","student");
if (!$con) {
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("facebook", $con);

$result = mysql_query("SELECT * FROM users");

while($row = mysql_fetch_array($result)) {
  echo $row['username'] . " " . $row['name'];
  echo "<br />";
}

mysql_close($con);

?> 

<p>Lopp.

Kui $_REQUEST väljadel ei ole väärtust, siis annab PHP rämeda warningu: http://dijkstra.cs.ttu.ee/~tammet/k4.php

<body>
Algus.
<p>

<?php
echo "Hi, I'm a <b>PHP</b> script with input a: ";
echo $_REQUEST['a'];
echo " and input b: ";
echo $_REQUEST['b'];
?>

<form method="post">
a <input type="text" name="a" autocomplete="off"><br>
b <input type="text" name="b" autocomplete="off"><br>
<input type="submit">
</form>

<p>
Lopp.
</body>

Warningu vältimiseks on mõistlik kasutada isset kontrollifunktsiooni: http://dijkstra.cs.ttu.ee/~tammet/k5.php

<body>
Algus.
<p>

<?php

if (isset($_REQUEST['a'])) { 
  echo "<br>input a: ";
  echo $_REQUEST['a'];
}
if (isset($_REQUEST['b'])) {
 echo "<br>input b: ";
 echo $_REQUEST['b'];
}

?>

<form method="post">
a <input type="text" name="a" autocomplete="off"><br>
b <input type="text" name="b" autocomplete="off"><br>
<input type="submit">
</form>

<p>
Lopp.
</body>

Andmebaasipäring, kus me ise paneme kokku sql where tingimuse vastavalt kasutaja antud väärtustele (siin näites ei ole see turvaliselt tehtud, vaata paari järgmist). http://dijkstra.cs.ttu.ee/~tammet/k6.php

<body>
Algus.
<p>

<?php

$con = mysql_connect("localhost","fstudent","student");
if (!$con) {
  die('Could not connect: ' . mysql_error());
}

$sex = "X";

mysql_select_db("facebook", $con);

if (isset($_REQUEST['sex'])) {
  $sex = $_REQUEST['sex'];
}

$q="SELECT * from users where sex='$sex'";

echo "query: $q <br>";
$result = mysql_query($q);

echo "leitud:<p>";
while($row = mysql_fetch_array($result)) {
  echo $row['username'] . " " . $row['name'];
  echo "<br />";
}

mysql_close($con);

?>

<form method="post">
sex  <input type="text" name="sex" autocomplete="off"><br>
<input type="submit">
</form>

<p>
Lopp.

Veidi keerukama where tingimuse kokkuklopsimine kasutaja antud väärtustest (endiselt ei ole turvaline): http://dijkstra.cs.ttu.ee/~tammet/k7.php

<body>
Algus.
<p>

<?php

$q="";
$c="";

function addcond($fld) {
  global $q, $c;

  if (isset($_REQUEST[$fld])  && $_REQUEST[$fld]!="") {
    if ($c!="") $c=$c . " and ";
    $c=$c . " $fld='" . $_REQUEST[$fld] ."' ";
  }
}

function main() {
  global $q, $c;

  $con = mysql_connect("localhost","fstudent","student");
  if (!$con) {
    die('Could not connect: ' . mysql_error());
  }

  mysql_select_db("facebook", $con);

  $q="SELECT * from users where ";
  $c="";

  addcond("username");
  addcond("name");
  addcond("sex");

  if ($c=="") {
    echo "<p>palun sisesta midagi otsinguvaljadele!<p>";
  } else {
    $q=$q . $c;
    echo "query: " . $q . "<br>";
    $result = mysql_query($q);

    echo "leitud:<p>";
    while($row = mysql_fetch_array($result)) {
      echo $row['username'] . " " . $row['name'];
      echo "<br />";
    }
  }
  mysql_close($con);
}

main();

?>

<form method="post">
username <input type="text" name="username" autocomplete="off"><br>
name <input type="text" name="name" autocomplete="off"><br>
sex  <input type="text" name="sex" autocomplete="off"><br>
<input type="submit">
</form>

<p>
Lopp.
</body>

Siin paneme juurde esmaselt vajaliku turva (et kasutaja ei saaks sql süntaksit sisestada), selleks on funktsioon mysql_real_escape_string: http://dijkstra.cs.ttu.ee/~tammet/k8.php

<body>
Algus.
<p>

<?php

$q="";
$c="";

function addcond($fld) {
  global $q, $c;

  if (isset($_REQUEST[$fld])  && $_REQUEST[$fld]!="") {
    if ($c!="") $c=$c . " and ";
    $c=$c . " $fld='" . mysql_real_escape_string($_REQUEST[$fld]) ."' ";
  }
}

function main() {
  global $q, $c;

  $con = mysql_connect("localhost","fstudent","student");
  if (!$con) {
    die('Could not connect: ' . mysql_error());
  }

  mysql_select_db("facebook", $con);

  $q="SELECT * from users where ";
  $c="";

  addcond("username");
  addcond("name");
  addcond("sex");

  if ($c=="") {
    echo "<p>palun sisesta midagi otsinguvaljadele!<p>";
  } else {
    $q=$q . $c;
    echo "query: " . $q . "<br>";
    $result = mysql_query($q);

    echo "leitud:<p>";
    while($row = mysql_fetch_array($result)) {
      echo $row['username'] . " " . $row['name'];
      echo "<br />";
    }
  }
  mysql_close($con);
}

main();

?>

<form method="post">
username <input type="text" name="username" autocomplete="off"><br>
name <input type="text" name="name" autocomplete="off"><br>
sex  <input type="text" name="sex" autocomplete="off"><br>
<input type="submit">
</form>

<p>
Lopp.
</body>

Siin on näide faili uploadimisest, seda aga redditi praksis vaja ei ole: http://dijkstra.cs.ttu.ee/~tammet/k9.php

<body>
Algus.
<p>

<?php

echo "Hi, I'm a <b>PHP</b> script uploading a file: ";
echo '<br> name ' . $_FILES['userfile']['name'];
echo '<br> type ' . $_FILES['userfile']['type'];
echo '<br> size ' . $_FILES['userfile']['size'];
echo '<br> tmp_name ' . $_FILES['userfile']['tmp_name'];
echo '<br> error '. $_FILES['userfile']['error'];

$uploaddir = '/tmp/uploads/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);

move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile);

?>

<form enctype="multipart/form-data" method="POST">
    <!-- MAX_FILE_SIZE must precede the file input field -->
    <input type="hidden" name="MAX_FILE_SIZE" value="30000" />
    <!-- Name of input element determines name in $_FILES array -->
    Send this file: <input name="userfile" type="file" />
    <input type="submit" value="Send File" />
</form>


<p>
Lopp.
</body>