Php where part等于null的sql语句?
在sql语句的where部分中,Php where part等于null的sql语句?,php,html,sql,Php,Html,Sql,在sql语句的where部分中,id=“.$\u请求['id']”;值从显示相应记录的组合框中馈送。在页面加载时,组合框没有选择值,因此sql语句在where部分上显示sql错误(id=“.$\u请求['id']”)。)?如何删除此错误 <div class="col-lg-6" style="display:none" id="d" > <select name="id
id=“.$\u请求['id']”;
值从显示相应记录的组合框中馈送。在页面加载时,组合框没有选择值,因此sql语句在where部分上显示sql错误(id=“.$\u请求['id']”)。
)?如何删除此错误
<div class="col-lg-6" style="display:none" id="d" >
<select name="id" id="id" class="span2" style="width:150px;" onchange="this.form.submit();">
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "valet";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$age = array();
$sql = "SELECT * FROM `tbl_companies` ";
$result = mysqli_query($conn, $sql);
// echo "User name=" . $row["name"]. "<br>";
?>
<option value="">-select company-</option>
<?php if (mysqli_num_rows($result) > 0) {
// output data of each row
while($row = mysqli_fetch_assoc($result)) {
$age[] = $row;
}
?>
<?php foreach($age as $key=>$row) {
echo "<option value='" . $row['id'] . "' " . (($_REQUEST['id'] == $row['id']) ? "selected": "") . ">" . $row["id"] . "</option>";
?>
<?php }
}
else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
header('Location: webservices.php');
}
mysqli_close($conn);
?>
</select>
<form action="" id="abc" method="post" >
<br><br>
<br>
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "valet";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$age = array();
if(strlen($_REQUEST['id']) > 0)
{
$sql = "SELECT company_name ,acess_code ,register_on FROM `tbl_companies` where id=".$_REQUEST['id'] ." ";
$result = mysqli_query($conn, $sql);
// echo "User name=" . $row["name"]. "<br>";
if (mysqli_num_rows($result) > 0) {
// output data of each row
while($row = mysqli_fetch_assoc($result)) {
$age[] = $row;
?>
<br><br><br>
<input type="text" id="company_name" value="<?php echo isset($row["company_name"])?$row["company_name"]:''; ?>" name="company_name" style="width: 460px;height: 50px;overflow: hidden;" placeholder="Company Name*">
<br>
<br><br><br>
<input type="text" id="acess_code" value="<?php echo isset($row["acess_code"])?$row["acess_code"]:''; ?>" name="acess_code" style="width: 460px;height: 50px;overflow: hidden;" placeholder="Acess Code*">
<br><br><br><br>
<input type="text" id="register_on" value="<?php echo isset($row["register_on"])?$row["register_on"]:''; ?>" name="register_on" style="width: 460px;height: 50px;overflow: hidden;" placeholder="Register On*">
<br><br><br><br>
<button name="editcompany" id="editcompany" type="submit" style="border:0;width:100px;margin-left: 45px;" >
<img src="images/save.png" alt="">
</button>
<button type="submit" style="border:0;width:100px;margin-left: 75px;">
<img src="images/cancel.png" alt="">
</button>
<?php
}
}
}
mysqli_close($conn);
?>
</form>
</div>
-精选公司-
您不应该使用!=比较来检查字符串是否为空。请改用strlen()>0。
其次,只需调试$_请求['id']中的内容,就可以知道当您将其留空时得到的值。然后您就可以使用它进行检查
第二种可能性是始终为组合框设置默认值
$id = (!empty($_REQUEST['id'])) ? $_REQUEST['id'] : '';
$sql = "SELECT company_name ,acess_code ,register_on FROM `tbl_companies` where id='".$id."'";
注意:C:\wamp\www\admin\webservices.php中的未定义索引:id在第行…它仍然不工作,请使用if(isset($\u REQUEST['id']){…}