无法添加或更新子行:外键约束失败(Mysql 和外键)
Cannot add or update a child row: a foreign key constraint fails (Mysql and Foreign key)
当我尝试 运行 代码时,出现此错误
Cannot add or update a child row: a foreign key constraint fails
(hotel_info
.results
, CONSTRAINT results_ibfk_5
FOREIGN KEY
(CustomerID
) REFERENCES customer
(CustomerID
) ON DELETE CASCADE
ON UPDATE CASCADE)
这是代码
$result = mysql_query("select customer.CustomerID from customer inner join results on customer.CustomerID = results.CustomerID where customer.Username = '".$aid."'");
if (false === $result)
{
echo mysql_error();
}
if (isset($_POST["submitbtn"]))
{
$LP = $_POST["LP"];
$budget = $_POST["budget"];
$checkin = $_POST["CheckIn"];
$checkout = $_POST["CheckOut"];
$unit = $_POST["unit"];
$smokep = $_POST["SmokeP"];
$spreq = $_POST["sp_req"];
if($checkin>$checkout)
{
?>
<script type="text/javascript">
alert("End Date must greater than Start Date.");
</script>
<?php
}
else
{
$query = mysql_query("INSERT INTO results(`LP`, `budget`, `CheckIn`, `CheckOut`, `unit`, `SmokeP`, `sp_req`, `CustomerID`) values ('$LP', '$budget',
'$checkin', '$checkout', '$unit', '$smokep', '$spreq', '$result')");
if (false === $query)
{
echo mysql_error();
}
echo "Reservation form has been submitted!<br>
<a href=view.php>view all</a>";
}
}
这是sql
CREATE TABLE IF NOT EXISTS `results` (
`BookID` int(10) NOT NULL AUTO_INCREMENT,
`LP` varchar(50) DEFAULT NULL,
`budget` varchar(50) DEFAULT NULL,
`CheckIn` varchar(50) DEFAULT NULL,
`CheckOut` varchar(50) DEFAULT NULL,
`unit` int(50) DEFAULT NULL,
`SmokeP` varchar(50) DEFAULT NULL,
`sp_req` varchar(255) DEFAULT NULL,
`CustomerID` int(10) NOT NULL,
PRIMARY KEY (`BookID`),
KEY `Username` (`CustomerID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=48 ;
CREATE TABLE IF NOT EXISTS `customer` (
`CustomerID` int(10) NOT NULL AUTO_INCREMENT,
`Username` varchar(50) NOT NULL,
`Password` varchar(50) NOT NULL,
`Email` varchar(50) NOT NULL,
`ContactNo` int(10) NOT NULL,
PRIMARY KEY (`CustomerID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;
因为这个错误我已经卡了两天了,请帮忙
从错误中可以看出外键约束失败。请检查您的 customer table,其中必须包含您尝试插入 results 的 CustomerID ] table 插入查询,即检查 $id 的值。您是否为 $id
分配了任何值
$query = mysql_query("INSERT INTO results(`LP`, `budget`, `CheckIn`, `CheckOut`, `unit`, `SmokeP`, `sp_req`, `CustomerID`) values ('$LP', '$budget',
'$checkin', '$checkout', '$unit', '$smokep', '$spreq', '$id')");
In above query value for $id not set so first assign value to that.
当我尝试 运行 代码时,出现此错误
Cannot add or update a child row: a foreign key constraint fails (
hotel_info
.results
, CONSTRAINTresults_ibfk_5
FOREIGN KEY (CustomerID
) REFERENCEScustomer
(CustomerID
) ON DELETE CASCADE ON UPDATE CASCADE)
这是代码
$result = mysql_query("select customer.CustomerID from customer inner join results on customer.CustomerID = results.CustomerID where customer.Username = '".$aid."'");
if (false === $result)
{
echo mysql_error();
}
if (isset($_POST["submitbtn"]))
{
$LP = $_POST["LP"];
$budget = $_POST["budget"];
$checkin = $_POST["CheckIn"];
$checkout = $_POST["CheckOut"];
$unit = $_POST["unit"];
$smokep = $_POST["SmokeP"];
$spreq = $_POST["sp_req"];
if($checkin>$checkout)
{
?>
<script type="text/javascript">
alert("End Date must greater than Start Date.");
</script>
<?php
}
else
{
$query = mysql_query("INSERT INTO results(`LP`, `budget`, `CheckIn`, `CheckOut`, `unit`, `SmokeP`, `sp_req`, `CustomerID`) values ('$LP', '$budget',
'$checkin', '$checkout', '$unit', '$smokep', '$spreq', '$result')");
if (false === $query)
{
echo mysql_error();
}
echo "Reservation form has been submitted!<br>
<a href=view.php>view all</a>";
}
}
这是sql
CREATE TABLE IF NOT EXISTS `results` (
`BookID` int(10) NOT NULL AUTO_INCREMENT,
`LP` varchar(50) DEFAULT NULL,
`budget` varchar(50) DEFAULT NULL,
`CheckIn` varchar(50) DEFAULT NULL,
`CheckOut` varchar(50) DEFAULT NULL,
`unit` int(50) DEFAULT NULL,
`SmokeP` varchar(50) DEFAULT NULL,
`sp_req` varchar(255) DEFAULT NULL,
`CustomerID` int(10) NOT NULL,
PRIMARY KEY (`BookID`),
KEY `Username` (`CustomerID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=48 ;
CREATE TABLE IF NOT EXISTS `customer` (
`CustomerID` int(10) NOT NULL AUTO_INCREMENT,
`Username` varchar(50) NOT NULL,
`Password` varchar(50) NOT NULL,
`Email` varchar(50) NOT NULL,
`ContactNo` int(10) NOT NULL,
PRIMARY KEY (`CustomerID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;
因为这个错误我已经卡了两天了,请帮忙
从错误中可以看出外键约束失败。请检查您的 customer table,其中必须包含您尝试插入 results 的 CustomerID ] table 插入查询,即检查 $id 的值。您是否为 $id
分配了任何值$query = mysql_query("INSERT INTO results(`LP`, `budget`, `CheckIn`, `CheckOut`, `unit`, `SmokeP`, `sp_req`, `CustomerID`) values ('$LP', '$budget',
'$checkin', '$checkout', '$unit', '$smokep', '$spreq', '$id')");
In above query value for $id not set so first assign value to that.