我是一名初学者，也是一名文凭学生。。。我已经使用localhost创建了数据库。。。我在查看数据库时遇到问题。。。请帮帮我…我希望你能帮我一个完整的代码。。。这是错误。。。
Warning: mysqli_select_db() expects exactly 2 parameters, 1 given in C:'xampp'htdocs'SLR'View S110 PC01.php on line 10
cannot select DB
这是我的密码。。。
<?php
$host="localhost"; // Host name
$username="root"; // Mysql username
$password=""; // Mysql password
$db_name="slr"; // Database name
$tbl_name="s110_pc01"; // Table name
// Connect to server and select databse.
mysqli_connect("$host", "$username", "$password")or die("cannot connect");
mysqli_select_db("$db_name")or die("cannot select DB");
$sql="SELECT * FROM $tbl_name";
$result=mysqli_query($sql);
$count=mysqli_num_rows($result);
?>
<table width="400" border="0" cellspacing="1" cellpadding="0">
<tr>
<td><form name="form1" method="post" action="">
<table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td bgcolor="#FFFFFF"> </td>
<td colspan="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong> </td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFFF">#</td>
<td align="center" bgcolor="#FFFFFF"><strong>Software ID</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Software Name</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Installed Date</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Expiry Date</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Product Key</strong></td>
</tr>
<?php
while($rows=mysqli_fetch_array($result)){
?>
<tr>
<td align="center" bgcolor="#FFFFFF"><input name="checkbox[]" type="checkbox" id="checkbox[]" value="<? echo $rows['id']; ?>"></td>
<td bgcolor="#FFFFFF"><? echo $rows['soft_id']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['soft_name']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['installed_date']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['expiry_date']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['product_key']; ?></td>
</tr>
<?php
}
?>
<tr>
<td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete" value="Delete"></td>
</tr>
<?php
// Check if delete button active, start this
if($delete){
for($i=0;$i<$count;$i++){
$del_id = $checkbox[$i];
$sql = "DELETE FROM $tbl_name WHERE soft_id='$soft_id'";
$result = mysqli_query($sql);
}
// if successful redirect to delete_multiple.php
if($result){
echo "<meta http-equiv='"refresh'" content='"0;URL=View S110 PC01.php'">";
}
}
mysqli_close();
?>
</table>
</form>
</td>
</tr>
</table>
如果您在此处查看php手册：http://php.net/manual/fr/mysqli.select-db.php
您将看到函数mysqli_select_db在输入中使用两个参数。
bool mysqli_select_db（mysqli$link，字符串$dbname）
所以你应该有
// Connect to server and select databse.
$conn = mysqli_connect($host, $username, $password) or die("cannot connect");
mysqli_select_db($conn, $db_name) or die("cannot select DB");
在mysqli函数中，选择数据库不需要单独的函数
以下方法足以连接和选择数据库，
// Connect to server and select databse.
$conn = mysqli_connect($host, $username, $password,$db_name)or die("cannot connect");
文件：http://php.net/manual/en/mysqli.select-db.php
In Mysqli you have to pass two parameters.
1) sql Connection
2) sql query
example :
<?php
// Connect to server and select database.
$con=mysqli_connect("$host", "$username",
"$password","$db_name")or die("cannot connect server ");
$name="abc";
$email="abc@gmail.com";
$sql="INSERT INTO $tbl_name(name, email)VALUES('$name','$email')";
$result=mysqli_query($con,$sql);
mysqli_close($con);
?>