SQLite SUM and IN commands for Android

public int calculateTotalSalaryForEmployees( long[] departmentIds )
{
    int total = 0;
    // create a list of ids to use in the IN statement
    // Arrays.toString creates String which looks like [1,2,3]
    String deptlist = Arrays.toString( departmentIds );

    // remove the enclosing brackets from id list
    String inClause = deptlist.substring( 1, deptlist.length() - 1 );
    String sql = "select sum(salary) from employees where department_id " +
        "in (" + inClause + ")";

    Cursor c = mDb.rawQuery( sql, null );
    // move to the first row of the cursor
    c.moveToFirst();
    total = c.getInt(0);
    c.close();

    return total;
}

Trying something new out here. As I’m programming I find many little hints and tips that I want to remember or share. Not the longer more in-depth posts I’ve been trying out with the subjects on Android HTTP and Ruby on Rails, but little quick things to put into ones toolbox.

So here’s the first one, a little method to retrieve the sum of all the salaries of employees within a department.  It utilizes the SQL SUM and IN commands.  It was surprisingly difficult to find the exact way to perform these command, but surprisingly obvious and easy once I figured it out.  Just the types of little tools I don’t want to loose.