Hello!
I just started learning PHP and MYSQL a few weeks ago and Im having a little trouble. Im trying to display data from my database when a user selects an option from a drop-down list. I was able to display an error if the user made no selection, then I added more code to query the database and I started receiving errors once I made a selection.
Ive been working on this for a couple of days now and I have ran out of ideas. Any help would be greatly appreciated!
Thank you!
HTML
Option 1: Select a field to display current book inventory
OR
Option 2: Select an author to display his/her books
PHP
// create global vars
$inventory = "";
$author = "";
$query = "";
$error = "";
// Connect to MySQL Server
$dbConnection = mysqli_connect[ $dbHost, $dbUser, $dbPassword, $dbName ];
if [ mysqli_connect_errno[] ] {// if the connection in previous statement failed:
die[ "Could not connect to the database server: " .
mysqli_connect_error[] . " " . mysqli_connect_errno[] .
"" ];
//die [] : quit or exit the program completely after displaying the error3 and the actual error
}
// get values from selection
if [$_GET['submitForm']] {
$inventory = $_GET['inventory'];
$author = $_GET['authorInfo'];
$error = validate[$inventory,$author];
}
// Build a SELECT query
function validate[$inventory,$author] {
if [[$inventory == 'select'] && [$author == 'select']] {
return "You must select an option!";
}
else if [[$inventory != 'select'] && [$author != 'select']] {
return "You may only select one option!";
}
elseif[$_GET['inventory']== 'all' and $_GET['authorInfo']== 'select']{
$query= "SELECT * FROM books";
//Get all books by selected author
}
elseif[$_GET['inventory']== 'select' and $_GET['authorInfo']!= 'select']{
$query= "SELECT books.Title, authors.Name
FROM books, authors, books_authors
WHERE books.ID = books_authors.BID
and authors.ID = books_authors.AID
and Name = '". $_GET['authorInfo'] . "'";
//Field info for specific author
}else{
$query = "SELECT books." . $_GET['inventory'] .
" FROM books, authors, books_authors
WHERE books.ID = books_authors.BID
and authors.ID = books_authors.AID
and Name ='" . $_GET['authorInfo'] . "'";
}
}
// Query the database
if [$query != Null] {
if [ ![ $result = mysqli_query[$dbConnection, $query] ] ]
{
print[ "
Could not execute query!
" ];
die[ mysqli_error[] . "" ];
} // end if
else {
echo "
" . $error . "
";
}
}
?>
" ];
foreach [ $row as $value ]
print[ "" ];
print[ "" ];
}
}
else {
echo "No results returned.";
}
//Release the returned data to free mysql resources
mysqli_free_result[$result];
mysqli_free_result[$inventory];
mysqli_free_result[$author];
//Close the database connection:
mysqli_close[ $dbConnection ];
?>
No Query Selected"; } ?>
$value
Video liên quan