在重复条目添加名称,如果空php mysql

ALTER TABLE table_name ADD UNIQUE INDEX index_name (column_name);

$query = "SELECT COUNT(*) FROM table_name WHERE column_name = 'value'";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_row($result);
if ($row[0] > 0) {
    echo "Duplicate entry found!";
} else {
    // Insert new entry
}

CREATE DATABASE database_name;

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

$connection = mysqli_connect($servername, $username, $password, $dbname);

if (!$connection) {
    die("Connection failed: " . mysqli_connect_error());
}