mysqli_query插入成功并抛出错误

这是你的问题:

$sql = mysqli_query($conn, $query);

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

你两次调用mysqli_query,第一个插入记录:

$sql = mysqli_query($conn, $query);

第二次,它只对字符串"1"运行查询,但随后您的错误报告连接错误的内容以报告问题.

怎么样

$result = mysqli_query($conn, $query);

if ($result) {
    echo "New record created successfully";
} else {
    echo "Error: " .  . "
" .  mysqli_error($conn);
}