Question

I have set up 2 two tables – table userid and table data in phpmyadmin. The userid table consists of a single column – id and the table data consists of the following columns- id|name|price. I have added an index in the column id of table userid to point to id of the table data. Now i have a user who makes certain selections inside an android application. I want to insert this data into the table data. I know i have to use jdbc and know how to enter data for table without any index. But i am confused as to how to go about doing it in the case of related tables. The userid is obtained from this link http://android-developers.blogspot.in/2011/03/identifying-app-installations.html. Would someone please tell me how to enter the data using java. (The confusion is how to enter the userid and the corresponding data ).

Answer 1

As long as you’re aware of the user id when you’re inserting a new record into the data table that’s all you need. Basically you’ll have:

Statement stmt = conn.createStatement();
stmt.executeUpdate( "INSERT INTO data (id, name, price) VALUES ('id from userid table', 'a name', 'a price')");

Obviously the params aren’t escaped properly (they really should be) and there’s no testing for errors, but that would get you started.

Then to, for example, select all the data related to a given userid, you would do something like:

Statement stmt = conn.createStatement();
stmt.executeQuery( "SELECT * FROM userid LEFT JOIN data WHERE userid.id = data.id" );