当mysqli连接存储在另一个包含的文件中时，如何在包含的文件中使用mysqli？
I'm about to use mysqli instead of mysql for the first time in my procedural PHP application.
index.php
include(db_conn.php);
<html>
<body>
<?php include(content.php);?>
</body>
</html
db_conn.php
<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
content.php
mysqli_query($con,"SELECT * FROM Persons");
mysqli_query($con,"INSERT INTO Persons (FirstName,LastName,Age)
# more code...
mysqli_query necessarily requires the connection variable and my connection is stored in variable $con in the included db_conn.php file which is unavailable in another included content.php file.
Within your content.php use require(db_conn.php); And if you have a function defined in there, you're going to have to put require(db_conn.php); INSIDE that function.
The database connection doesn't seem to have exactly the same scoping as a standard variable.
I know when coding it, you feel like "I should only have to include this once!" but shrug get everything else working first, and if someone wants to pay you to go back and try to "fix" this... work on it then. ;)