Shortcode attributes that query the database - php

Question

I am trying to create a shortcode that returns a list of doctors matching a specialty.
So far, I can get the base shortcode to return the contents of the entire table, but I can't get it to query based on an attribute string.
Here's what I have:
// Add Shortcode
function list_docs( $atts ) {
// Attributes
$atts = shortcode_atts(
array(
'specialty' => '',
),
$atts,
'doctors'
);
global $wpdb;
$specialty = $atts['specialty'];
$specget = $wpdb->prepare("SELECT * FROM doctors WHERE specialty = '%s'", $specialty);
$specresults = $wpdb->get_results($specget);
foreach($specresults as $details) {
echo $details;
}
}
add_shortcode( 'doctors', 'list_docs' );
If I query the database directly with:
SELECT * FROM `doctors` WHERE `specialty` = 'cardiology'
I get the expected result.
I'm trying to call it with [doctors specialty="cardiology"] (I've tried double and single quotes) on the WordPress page.
Right now, I don't know what I don't know. I'm not sure if I've entered something wrong, have a typo, or am missing a line of code. Any assistance would be terrific.

Answer 1

May be problem is not with the query at all assuming that your table name is indeed doctors( & not wp_doctors or something like that )
$specresults will contain an array of objects. Let's say your doctors table has name column, then below changes may work for you.
function list_docs( $atts ) {
// Attributes
$atts = shortcode_atts(
array(
'specialty' => '',
),
$atts,
'doctors'
);
global $wpdb;
$specialty = $atts['specialty'];
$specget = $wpdb->prepare( 'SELECT * FROM doctors WHERE specialty = %s', $specialty );
$specresults = $wpdb->get_results( $specget );
if ( $specresults ) {
$doctor_names = array_map(
function( $doctor_object ) {
return $doctor_object->name;
},
$specresults
);
return implode( ', ', $doctor_names );
}
return '';
}
add_shortcode( 'doctors', 'list_docs' );
Couple of things to keep in mind:-
Shortcodes should always return & not echo directly.
Query only for required data from the database as far as possible instead of doing *
If you are going to need only one column, prefer using get_col method on $wpdb instead of get_results.

Answer 2

Please try with this -
function list_docs( $atts ) {
global $wpdb;
$specialty = $atts['specialty'];
$specget = $wpdb->prepare("SELECT * FROM doctors WHERE specialty = %s", $specialty);
$specresults = $wpdb->get_results($specget);
foreach($specresults as $details) {
echo $details;
}
}
add_shortcode( 'doctors', 'list_docs' );