How can I select all the data from a table with condition?

Question

I am new to android programming and I am having trouble with queries. I tried to search for similar questions but I found nothing :) so, here..

given this patientinfo table

patient_id | name | gender | age 
      1    | jen  | female | 20
      2    | jay  |  male  | 19

and records table

patient_id |   date   | description
      1    | 01-01-14 | healthy!
      1    | 02-01-14 | healthy!
      2    | 01-01-14 | needs medication.

I'd like to get all the records of a certain patient. like for example, if I choose patient1.. all records of patient1 will be displayed.

this is my query..

$query = "SELECT * FROM records INNER JOIN patientinfo ON records.patient_id = patientinfo.patient_id WHERE records.patient_id = $patient_id";

try{
    $stmt = $dbname->prepare($query);
    $result = $stmt->execute(); 

}catch(PDOException $ex){
        $response["success"] = 0;
        $response["message"] = $ex;

        die(json_encode($response));
    }

but it gives me an error in sql syntax, I think it's in the $patient_id

errorInfo: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use.

Thank you in advance! hoping for an answer! Thanks :)

Answer 1

Try by:

SELECT *
FROM patientinfo, records
WHERE (patientinfo.patient_id = $patient_id) AND (patientinfo.patient_id = records.patient_id);

You may also specifically list the columns to show, and assign them an alias, for instance:

SELECT records.date AS the_date

The WHERE records.patient_id = $patient_id seems ok as long as $patient_id is not an empty string. For that, I'd echo the query prior to executing it and checking whether it's ok.