jdbx心得笔记02----database，rs元数据使用

package com;import java.sql.Connection;import java.sql.DatabaseMetaData;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.SQLException;import java.sql.Statement;public class TestJDBC3 {public static void main(String[] args) {Connection conn = null;Statement stmt=null;ResultSet rs=null;try {Class.forName("oracle.jdbc.driver.OracleDriver");String url="jdbc:oracle:thin:@10.12.36.201:1521:xxxxxx";String dbUsername="openlab";String dbPassword="open123"; conn=DriverManager.getConnection(url, dbUsername, dbPassword); DatabaseMetaData dmd=conn.getMetaData(); System.out.println("数据库产品名称\t"+dmd.getDatabaseProductName()); System.out.println(dmd.getDatabaseProductVersion()); System.out.println(dmd.getDriverName()); System.out.println(dmd.getURL()); System.out.println(dmd.getUserName()); System.out.println(dmd.getStringFunctions()); //--------------------------------------------// String sql="select * from emp"; stmt=conn.createStatement(); rs=stmt.executeQuery(sql); ResultSetMetaData rsm=rs.getMetaData();//结果集元数据获得 int count=rsm.getColumnCount();//一共有多少列 stmt.setMaxFieldSize(8); for (int i = 1; i <count; i++) { System.out.print(rsm.getColumnName(i)+"\t"+"\t");} System.out.println(); while(rs.next()){ System.out.print(rs.getInt("empno")+"\t\t"); System.out.print(rs.getString("ename")+"\t\t"); System.out.print(rs.getString("job")+"\t\t"); System.out.print(rs.getString("mgr")+"\t\t"); System.out.print(rs.getDate("hiredate")+"\t\t"); System.out.print(rs.getDouble("sal")+"\t\t"); System.out.println(rs.getDouble("comm")+"\t\t"); System.out.println(); }} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}finally{try {stmt.close();} catch (SQLException e1) {e1.printStackTrace();}try {rs.close();} catch (SQLException e1) {e1.printStackTrace();}try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}}