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我想通過Java Swing應用程序爲jfreechart可視化使用JDBC從Hive表中提取結構數據結構<>。在執行SQL查詢時拋出一個SQLException
錯誤,它在我得到的異常處引發(rs.getString(「user.name」))。請給我一個建議如何使用JDBC應用程序從配置單元表中獲取結構數據?如何使用JDBC從配置單元表中獲取結構數據?
String s1 = jTextField1.getText();
String s2 = jTextField2.getText();
String s3 = jTextField4.getText();
try
{
Class.forName("org.apache.hive.jdbc.HiveDriver");
Connection con = DriverManager.getConnection("jdbc:hive2://localhost:10000/"+s1,"arunachalam","");
Statement st = con.createStatement();
String sql = "select user.name,user.followers_count c from "+s2+" order by c desc";
ResultSet rs = st.executeQuery(sql);
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
while(rs.next())
{
String name = rs.getString("user.name");
int count = rs.getInt("user.followers_count");
dataset.setValue(count,name,name);
}
JFreeChart chart = ChartFactory.createBarChart("Followers Count", "Screen Name", "Users Follower Count", dataset, PlotOrientation.VERTICAL, false, true, false);
CategoryPlot p = chart.getCategoryPlot();
int width = 560;
int height = 370;
File bchart = new File("Chart.jpeg");
ChartUtilities.saveChartAsJPEG(bchart , chart , width , height);
}
catch(Exception e)
{
showMessageDialog(null, e);
}
使用'rs.getString(1);'而不是? –
感謝兄弟。有效。 – Arunachalam