Lihtsaid php ja mysql näiteid

Allpool on näited kasutajana st2014 ja andmebaasiga st2014.

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
$con = mysqli_connect("localhost","st2014","progress","st2014");
if (!$con) {
  die('Could not connect: ' . mysqli_connect_error());
}

$result = mysqli_query($con,"SELECT * FROM tt_users");

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

mysqli_close($con)
?> 

<p>Lopp.

Kui $_REQUEST väljadel ei ole väärtust, siis võib mõni PHP versioon anda rämeda warningu (ja mõni teine jälle ei pruugi): 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

$con = mysqli_connect("localhost","st2014","progress","st2014");
if (!$con) {
  die('Could not connect: ' . mysqli_connect_error());
}

$username = "tanel";

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

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

echo "query: $q <br>";
$result = mysqli_query($con,$q);

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

mysqli_close($con);

?>

<form method="post">
username  <input type="text" name="username" 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 mysqli_real_escape_string: http://dijkstra.cs.ttu.ee/~tammet/k8.php

<body>
Algus.
<p>

<?php

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

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

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

function main() {
  global $q, $c;
  $con = mysqli_connect("localhost","st2014","progress","st2014");
  if (!$con) {
    die('Could not connect: ' . mysqli_error());
  }

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

  addcond($con,"username");
  addcond($con,"name");
  addcond($con,"sex");

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

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