php 检查数据库连接，否则显示消息
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Check for database connection, otherwise display message
提问by Chriswede
I would like to check if the website can connect to mySQL. If not, I would like to display an error saying that the user should try to access the page again in a few minutes...
我想检查该网站是否可以连接到mySQL。如果没有，我想显示一个错误，提示用户应该在几分钟后再次尝试访问该页面...
I really do not know how to do this ;)
我真的不知道该怎么做；)
Any help would be greatly appreciated!
任何帮助将不胜感激！
string mysql_error ([ resource $link_identifier ] )
But how do I use this?
但是我如何使用它？
This just gives me the error, but I want the message to display with any error.
这只是给我错误，但我希望消息显示任何错误。
Thanks
谢谢
回答by psyklopz
Try this:
尝试这个：
<?php
$servername = "localhost";
$database = "database";
$username = "user";
$password = "password";
// Create connection
$conn = new mysqli($servername, $username, $password, $database);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>
回答by tony gil
very basic:
非常基本的：
<?php
$username = 'user';
$password = 'password';
$server = 'localhost';
// Opens a connection to a MySQL server
$connection = mysql_connect ($server, $username, $password) or die('try again in some minutes, please');
//if you want to suppress the error message, substitute the connection line for:
//$connection = @mysql_connect($server, $username, $password) or die('try again in some minutes, please');
?>
result:
结果：
Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'user'@'localhost' (using password: YES) in /home/user/public_html/zdel1.php on line 6 try again in some minutes, please
警告: mysql_connect() [function.mysql-connect]: Access denied for user 'user'@'localhost' (using password: YES) in /home/user/public_html/zdel1.php on line 6 过几分钟再试一次，请
as per Wrikken's recommendation below, check out a complete error handler for more complex, efficient and elegant solutions: http://www.php.net/manual/en/function.set-error-handler.php
根据下面 Wrikken 的建议，查看完整的错误处理程序以获得更复杂、有效和优雅的解决方案：http://www.php.net/manual/en/function.set-error-handler.php
回答by irenecarnay
Please check this:
请检查这个：
$servername='localhost';
$username='root';
$password='';
$databasename='MyDb';
$connection = mysqli_connect($servername,$username,$password);
if (!$connection) {
die("Connection failed: " . $conn->connect_error);
}
/*mysqli_query($connection, "DROP DATABASE if exists MyDb;");
if(!mysqli_query($connection, "CREATE DATABASE MyDb;")){
echo "Error creating database: " . $connection->error;
}
mysqli_query($connection, "use MyDb;");
mysqli_query($connection, "DROP TABLE if exists employee;");
$table="CREATE TABLE employee (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP
)";
$value="INSERT INTO employee (firstname,lastname,email) VALUES ('john', 'steve', '[email protected]')";
if(!mysqli_query($connection, $table)){echo "Error creating table: " . $connection->error;}
if(!mysqli_query($connection, $value)){echo "Error inserting values: " . $connection->error;}*/
