[英]PHP MySQL query database and WHERE clause
我正在學習PHP和MySQL,並且在構建時遇到一兩個問題。
我有一個HTML表單,用戶可以輸入他們的詳細信息和狗的詳細信息。 然后,腳本檢查數據庫中的用戶名和狗名。 如果兩者都存在於數據庫中,則更改狗表上的user_ID以更改所有權。 如果用戶不存在,則將用戶詳細信息輸入數據庫,並更改所有權。
我確實完成了所有工作,但是沒有從表單中使用bindParam進行收集,並被告知這將是一個更好的選擇。 這就是樂趣的開始。 現在,我可以使用以下腳本對表中的行進行計數,但是,我無法在SELECT查詢中使用WHERE子句。 我曾嘗試放置“ WHERE name_first =:name_first”,但這失敗,並出現“ Parameter not defined”錯誤。
我需要能夠同時使用用戶的名字和姓氏,以便能夠從數據庫中選擇該用戶ID。
關於准備好的陳述的使用,我還有另一個問題。 如果我使用腳本頂部的語句從數據庫中進行SELECT,並且所有表單輸入都綁定到$ STH,那么我該如何運行另一個查詢,例如,如何使用用戶名將用戶詳細信息插入數據庫中?相同的約束?
有人可以看一下腳本,然后告訴我我要去哪里了嗎?
<?php
/***mysql username***/
$user = 'root';
/***mysql password***/
$pass = '';
if ($_SERVER['REQUEST_METHOD'] == "POST") {
try {
$DBH = new PDO('mysql:host=localhost;dbname=kennel_cert;', $user, $pass);
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$DBH->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
//Queries
$sql1 = "SELECT user_ID FROM user_details";
$sql2 = "SELECT dog_ID FROM dog_details";
$STH = $DBH->prepare("SELECT * FROM user_details"); //Needs a WHERE clause to work
//var_export($STH);
//User details form
$STH->bindParam(':name_first', $_POST['name_first']);
$STH->bindParam(':name_last', $_POST['name_last']);
$STH->bindParam(':email', $_POST['email']);
$STH->bindParam(':telephone', $_POST['telephone']);
$STH->bindParam(':name_number', $_POST['name_number']);
$STH->bindParam(':street', $_POST['street']);
$STH->bindParam(':city', $_POST['city']);
$STH->bindParam(':county', $_POST['county']);
$STH->bindParam(':postcode', $_POST['postcode']);
//Dog details form
$STH->bindParam(':dog_reg', $_POST['dog_reg']);
$STH->bindParam(':name', $_POST['name']);
$STH->bindParam(':microchip', $_POST['microchip']);
$STH->bindParam(':gender', $_POST['gender']);
$STH->bindParam(':day', $_POST['day']);
$STH->bindParam(':month', $_POST['month']);
$STH->bindParam(':year', $_POST['year']);
$STH->execute(); //Execute the select script
//Use this to count the users - However without the WHERE it is counting all users not the one submitted into the form
if($STH->rowCount() > 0) {
echo "Exists <br>"; }
else {
echo "Doesn't exist <br>"; }
//var_export($userQuery); //Displays the contents of the query for testing
//Find if user exists in database - Again another way of counting the total but not the one inputed into the form
$userResult = $DBH->query($sql1);
if ($userResult !== false) {
$count = $userResult->rowCount();
echo 'Number of users: '.$count. '<br>';
foreach($userResult as $row) {
echo $row['user_ID'].'<br>';
}
}
//Find if dog exists in database - Again another way of counting the total but not the one inputed into the form
$dogResult = $DBH->query($sql2);
if ($dogResult !== false) {
$count = $dogResult->rowCount();
echo 'Number of dogs: '.$count. '<br>';
foreach($dogResult as $row) {
echo $row['dog_ID'].'<br>';
}
}
} catch (PDOException $e) {
echo $e->getMessage();
}
//echo "<p>Data submitted successfully</p>";
}
//Disconnect from the server
$DBH = null;
?>
確定,所以我將查詢更改為如下所示:
$sql = "SELECT user_ID
FROM user_details
WHERE name_first = :name_first
AND name_last = :name_last";
$STH = $DBH->prepare($sql);
當我運行它時,我得到這個錯誤:
PDOStatement::__set_state(array( 'queryString' => 'SELECT user_ID FROM user_details WHERE name_first = :name_first AND name_last = :name_last', ))
SQLSTATE[HY093]: Invalid parameter number: parameter was not defined
我完全迷失了方向,我走來走去,找不到任何可以幫助我解決這個問題的東西。
我確實按照使用此設置的說明運行了腳本,但是,有人告訴我對表單使用bindParam,這正在殺死腳本和我。
<?php
/***mysql username***/
$user = 'root';
/***mysql password***/
$pass = '';
if ($_SERVER['REQUEST_METHOD'] == "POST") {
try {
$DBH = new PDO('mysql:host=localhost;dbname=kennel_cert;', $user, $pass);
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$DBH->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
//Queries
$userQuery = $DBH->query("SELECT user_ID FROM user_details WHERE name_first = '$first' AND name_last = '$last'"); //Checks if the user exists in the database
$dogQuery = $DBH->query("SELECT dog_ID FROM dog_details WHERE dog_ID = '$dog_reg' AND name = '$name' AND gender = '$gender'");
//User details form
$first = $_POST['name_first'];
$last = $_POST['name_last'];
$email = $_POST['email'];
$telephone = $_POST['telephone'];
$name_number = $_POST['name_number'];
$street = $_POST['street'];
$city = $_POST['city'];
$county = $_POST['county'];
$postcode = $_POST['postcode'];
//Dog details form
$dog_reg = $_POST['dog_reg'];
$name = $_POST['name'];
$microchip = $_POST['microchip'];
$gender = $_POST['gender'];
$day = $_POST['day'];
$month = $_POST['month'];
$year = $_POST['year'];
$u = ""; //Variable for counting users
$d = ""; //Variable for counting dogs
//var_export($userQuery); //Displays the contents of the query for testing
//Find if user exists in database
foreach($userQuery as $row1) { //Count the number of users in the database
$u++;
}
//Find if dog exists in database
foreach($dogQuery as $row2) { //Count the number of dogs in the database
$d++;
}
//The echos are for testing purposes
echo "Dog ID is: ".$row2['dog_ID']."<br>"; //Finds the ID of the dog and displays it
echo "User ID is: ".$row1['user_ID']."<br>"; //Finds the ID of the user and displays it
$newUserID = $row1['user_ID']; //Store the ID for future use
$newDogID = $row2['dog_ID']; //Store the ID for future use
//Perform if both user and dog exist
if ($u > 0 && $d > 0) { //If both the user and the dog exist in the database change the owner of the dog
echo "Both Match"; //Confirm both exist
$q = $DBH->prepare("UPDATE dog_details SET user_ID = '$newUserID' WHERE dog_ID = '$newDogID'"); //update the table to change ownership
$q->execute(); //Execute the change
}
// Perform if only dog exists
elseif ($u == 0 && $d > 0) { //If the user does not exist but the dog does.
echo "Dog matches but user does not exist"; //Confirm what exists
//Insert user details into user_details table and set the foreign user_ID key in the dog_details table
$q1 = $DBH->prepare("INSERT INTO user_details (name_first,name_last,email,telephone,name_number,street,city,county,postcode) VALUES ('$first','$last','$email','$telephone','$name_number','$street','$city','$county','$postcode')");
$q1->execute();
echo "<br>Insert complete<br>";*/
}
elseif ($u > 0 && $d == 0) {
echo "The dog does not exist - this is a problem";
//Form needs returning with values and asks user to check details
}
elseif ($u == 0 && $d == 0) {
echo "Both don't match";
}
} catch (PDOException $e) {
echo $e->getMessage();
}
//echo "<p>Data submitted successfully</p>";
}
//Disconnect from the server
$DBH = null;
?>
查閱需要在綁定參數之前將占位符放在sql中的手冊 :
$query = "SELECT * FROM user_details
WHERE name_first = :name_first
AND name_last = :name_last
AND email = :email
etc...";
$STH = $DBH->prepare($query);
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