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How to use PHP to make a query statement: 1. Create a PHP sample file; 2. Use mysqli_connect to connect to the database; 3. Pass "$q = "SELECT * FROM user WHERE gender = '".$gender ."'";$result = mysqli_query($db,$q);" statement can be used to implement the query.
The operating environment of this tutorial: Windows 7 system, PHP version 8.1, Dell G3 computer.
How to use php to make a query statement?
php uses select statements to query data information
<html>
<head>
<title>Finding User</title>
</head>
<body>
<h2>Finding users from mysql database.</h2>
<form action="selectformhandler.php" method="post">
Select gender:
<select name="gender">
<option value="male">man</option>
<option value="female">woman</option>
</select><br />
<input name="submit" type="submit" value="Find"/>
</form>
</body>
</html><html>
<head>
<title>User found</title>
</head>
<body>
<h2>User found from mysql database.</h2>
<?php
$gender = $_POST['gender'];
if(!$gender){
echo "Error: There is no data passed.";
exit;
}
if(!get_magic_quotes_gpc()){
$gender = addslashes($gender);
}
@ $db = mysqli_connect('localhost','root','12345678');
mysqli_select_db($db,'testphp');
if(mysqli_connect_errno()){
echo "Error: Could not connect to mysql database.";
exit;
}
$q = "SELECT * FROM user WHERE gender = '".$gender."'";
$result = mysqli_query($db,$q);
$rownum = mysqli_num_rows($result);
for($i=0; $i<$rownum; $i++){
$row = mysqli_fetch_assoc($result);
echo "Id:".$row['id']."<br />";
echo "Name:".$row['name']."<br />";
echo "Age:".$row['age']."<br />";
echo "Gender:".$row['gender']."<br />";
echo "Info:".$row['info']."<br />";
}
mysqli_free_result($result);
mysqli_close($db);
?>
</body>
</html>Recommended learning: "PHP Video Tutorial"
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