PHP - 基本选择查询仅返回mysql数据库的第一行

I've been running the query oh phpMyAdmin and it shows all the rows, but my query in php only returns the first row.

$result = $mydb -> query("SELECT * FROM music_sheet WHERE category='".$_REQUEST["submitter"]."'"); 

print(count($result)); //always returns 1

for ($x = 0; $x < count($result); $x++) {
    $row = mysqli_fetch_row($result);
}

For reference, here's why count() is returning 1. From the manual:

If the parameter is not an array or not an object with implemented Countable interface, 1 will be returned. There is one exception, if array_or_countable [the parameter] is NULL, 0 will be returned.

Since $result is a resource (object) that is returned from your query, not an array which you would get within your loop getting the actual data out of the resource, count($resource) will return 1.

Your solution is of course to use mysqli_num_rows(). To retrieve data from this resource, you need to loop over it as you are doing, but either use mysqli_num_rows() in place of count(), or other (more common) ways of looping through a result set, like so:

while($row = mysqli_fetch_row($result)) {
    // do stuff
}

You have to use mysqli_num_rows($result) function to count rows which are returned by MySQLi query.

Try this

echo mysqli_num_rows($result);

while($row = mysqli_fetch_row($result)) {
// write your code...
}

Use this instead of the for loop

the first thing that the query method returns to you is a resource/object. This query method always return a mysqli_result object for successful queries using SELECT, SHOW, DESCRIBE or EXPLAIN queries . For other successful queries mysqli_query() will return TRUE. For that reason it always count it as "1", what you should try is:

$result = $mydb -> query("SELECT * FROM music_sheet WHERE category='".$_REQUEST["submitter"]."'"); 

$numRows = $result->num_rows;

print(count($numRows)); //it should show you the total amount of rows

//verify the amount of rows before of tryng to loop over it
if ($numRows) {
    while($object = mysqli_fetch_object($result)){
    //for each loop you will have an object with the attributes of the row
    echo $object->song_name; 
    }
}

This should work,

Regards.