MYSQLi PHP连接

Question

以下是一个有效的mysqli php connect insert语句吗？

if($mysql_query = $conn->query("INSERT INTO users (username,password,question,securityanswer) VALUES ('$uname','$upass','$selectquestion','$answer')"))
{
?>
    <script>alert('successfully registered ');</script>
    <?php
}
 else
{
?>
    <script>alert('error while registering you...');</script>
    <?php
}
}

但是我在收到错误时收到错误“注册你......”

由于

Answer 1

问题已解决。 ＆＃34; user_id＆＃34;存在问题。正在更新的列主键重复（0值）此错误＆＃34;重复条目＆＃39; 0＆＃39;关键＆＃39; PRIMARY＆＃39;。在phpmyadmin中使用自动增量更新user_id列后，INSERT查询已成功更新。

使用以下代码检查错误有帮助。

 die(mysqli_error($conn));

Answer 2

一个简单的例子：

<?php  
//Create the connection  

$con = mysqli_connect("HostName","UserName","password","DBName") or die("Some error occurred during connection " . mysqli_error($con));  

// Write query

$strSQL = "SELECT username FROM MyTable";

// Execute the query.

$query = mysqli_query($con, $strSQL);
while($result = mysqli_fetch_array($query))
{
  echo $result["username"]."
";
}

// Close the connection
mysqli_close($con);

?>

Answer 3

你能用连接语句粘贴整个块吗？ 否则SQL语句看起来很好。你不应该将输入转义为MySQL

if($mysql_query = $conn->query("INSERT INTO users (username,password,question,securityanswer) VALUES ('$uname','$upass','$selectquestion','$answer')"))

Why using if($mysql_query = $conn->query ?

更好

if（$ conn-＆gt; query（＆＃34; INSERT INTO users（username，password，question，securityanswer）VALUES（＆＃39; $ uname＆＃39;，＆＃39; $ upass＆＃39;， ＆＃39; $ selectquestion＆＃39;，＆＃39; $ answer＆＃39;）＆＃34;）=== TRUE）