ResultSetMetaData 和 DatabaseMetaData

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ResultSetMetaData:用来分析 "结果集"信息
DatabaseMetaData:用来分析是"数据库"信息

//做一个简单的 查询执行器

package com.enhance.jdbc;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.util.Properties;
import java.util.Vector;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;

public class QueryExecutor {
	JFrame jf = new JFrame("查询执行器");
	private JScrollPane scrollPane;
	private DefaultTableModel model;
	private JButton execBn=new JButton("查询");
	
	private JTextField sqlField=new JTextField(40);
	
	private static Connection conn;
	private static Statement stmt;
	private static ResultSet rs;
	
	static {
		try {
			
			Properties prop=new Properties();
			FileInputStream in=new FileInputStream("src/mysql.ini");
			prop.load(in);
			in.close();
			String driver =prop.getProperty("driver");
			String url=prop.getProperty("url");
			String user=prop.getProperty("user");
			String pass=prop.getProperty("pass");
			Class.forName(driver);
			conn=DriverManager.getConnection(url,user,pass);
			stmt=conn.createStatement();
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}
	class ExecListener implements ActionListener{
		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			if(scrollPane!=null){
				jf.remove(scrollPane);
			}
			try {
				rs=stmt.executeQuery(sqlField.getText());
				System.out.println();
				ResultSetMetaData rsmd=rs.getMetaData();
				Vector columnNames=new Vector();
				System.out.println("cn"+rsmd.getColumnCount());
				Vector data=new Vector();
				for (int i = 0; i < rsmd.getColumnCount(); i++) {
					columnNames.add(rsmd.getColumnName(i+1));
				}
				while(rs.next()){
					Vector v=new Vector();
					for (int i = 0; i < rsmd.getColumnCount(); i++) {
						v.add(rs.getString(i+1));
					}
					data.add(v);
				}
				model = new DefaultTableModel(data,columnNames);
				JTable table=new JTable(model);
				scrollPane=new JScrollPane(table);
				jf.add(scrollPane);
				jf.validate();
				
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
	}
	public void init(){
		JPanel top=new JPanel();
		top.add(new JLabel("输入查询语句:"));
		top.add(sqlField);
		top.add(execBn);
		execBn.addActionListener(new ExecListener());
		sqlField.addActionListener(new ExecListener());
		
		jf.add(top,BorderLayout.NORTH);
		jf.setSize(640,480);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.setVisible(true);
	}
	
	public static void main(String[] args) {
		new QueryExecutor().init();
	}

}

//分析数据库信息

package com.enhance.jdbc;

import java.io.FileInputStream;
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.util.Properties;

public class DataBaseMetaDataTest {
	private String driver;
	private String url;
	private String user;
	private String pass;
	private Connection conn;
	private ResultSet rs;
	public void initParam(String paramFile) throws Exception{
		Properties prop=new Properties();
		prop.load(new FileInputStream(paramFile));
		driver=prop.getProperty("driver");
		url=prop.getProperty("url");
		user=prop.getProperty("user");
		pass=prop.getProperty("pass");
	}
	
	public void info() throws Exception{
		try {
			Class.forName(driver);
			conn=DriverManager.getConnection(url,user,pass);
			//获取DataBaseMeteData对象
			DatabaseMetaData dbmd=conn.getMetaData();
			//获取MySql支持的所有类型
			ResultSet rs=dbmd.getTableTypes();
			System.out.println("----MySql支持的表的类型信息----");
			printResultSet(rs);
			//获取当前数据库的全部数据表
			rs=dbmd.getTables(null,null, "%", new String[]{"TABLE"});
			System.out.println("----当前数据库中的所有表信息----");
			printResultSet(rs);
			
			rs=dbmd.getPrimaryKeys(null, null, "my_test");
			System.out.println("----my_test表中的主键信息----");
			printResultSet(rs);
			
			rs=dbmd.getProcedures(null, null, "%");
			System.out.println("----当前数据库中所有存储过程信息----");
			printResultSet(rs);
			
			rs=dbmd.getCrossReference(null, null, "time_zone", null, null, "time_zone_name");
			System.out.println("----time_zone表和time_zone_name表之间的外键约束----");
			printResultSet(rs);
			
			rs=dbmd.getColumns(null, null, "my_test", "%");
			System.out.println("----my_test表的全部数据列----");
			printResultSet(rs);
			
			System.out.println(dbmd.getDatabaseProductName());
			System.out.println(dbmd.getDatabaseProductVersion());
			System.out.println(dbmd.getDriverName());
			System.out.println(dbmd.getDriverVersion());
			
			
		} finally{
			if(rs!=null)
				rs.close();
			if(conn!=null)
				conn.close();
		}
	}
	
	public void printResultSet(ResultSet rs) throws SQLException{
		ResultSetMetaData rsmd=rs.getMetaData();
		
		for (int i = 0; i < rsmd.getColumnCount(); i++) {
			System.out.print(rsmd.getColumnName(i+1)+"\t");
		}
		System.out.println();
		while(rs.next()){
			for (int i = 0; i < rsmd.getColumnCount(); i++) {
				System.out.print(rs.getString(i+1)+"\t");
			}
			System.out.println();
		}
		rs.close();
	}
	
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub
		DataBaseMetaDataTest dbmdt=new DataBaseMetaDataTest();
		dbmdt.initParam("src/mysql.ini");
		dbmdt.info();
	}

}

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