php写增删改（php+mysql增删改查）

以下是一个简单的示例代码，展示了如何使用PHP和MySQL进行增删改查操作：

连接到MySQL数据库：

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

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

插入数据：

$sql = "INSERT INTO table_name (column1, column2, column3) VALUES ('value1', 'value2', 'value3')";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

删除数据：

$sql = "DELETE FROM table_name WHERE condition";

if ($conn->query($sql) === TRUE) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . $conn->error;
}

更新数据：

$sql = "UPDATE table_name SET column1 = 'new_value' WHERE condition";

if ($conn->query($sql) === TRUE) {
    echo "Record updated successfully";
} else {
    echo "Error updating record: " . $conn->error;
}

查询数据：

$sql = "SELECT * FROM table_name WHERE condition";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "Column1: " . $row["column1"]. " - Column2: " . $row["column2"]. " - Column3: " . $row["column3"]. "<br>";
    }
} else {
    echo "0 results";
}

关闭数据库连接：

$conn->close();

请注意，上述代码中的"table_name"应该替换为您的实际表名，"column1"、"column2"、"column3"应替换为您的实际列名，"condition"应替换为您的实际查询条件。