Getting the error “java.sql.SQLException: After end of result set” when using ResultSet .getArray()

Question

I'm trying to get a table from my SQL database using a select distinct query and then putting it into an array. However, I am getting an error when I try to save the array as a variable.

Code:

private ResultSet query(String query) throws SQLException {
    assert testConn();
    try {
        Statement statement = connection.createStatement();
        return statement.executeQuery(query);
    } catch (SQLException e) {
        e.printStackTrace();
    }
    throw new SQLException();
}


private boolean testConn(){
    try {
        return connection.isValid(1);
    } catch (SQLException e){
        return false;
    }
}

@Test
void test_rs(){
    try {
        ResultSet rs = query("select distinct client_id from email_filtering_scores;");
        Array a = rs.getArray("client_id");
        String[] set = (String[])a.getArray();
        System.out.println(Arrays.deepToString(set));
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

I don't know why this is throwing the SQLException so any help is appreciated.

Thanks in advance.

PS. I don't know what best practice is for using jdbc so if there's anything that egregious with my code I would love some advice.

Answer 1

Just check if the resultset has values using next()

    if (rs.next()) {
        Array a = rs.getArray("client_id");
        String[] set = (String[]) a.getArray();
        System.out.println(Arrays.deepToString(set));
    }