SELECT DISTINCTROW Employees.Name, SalaryRanges.Min, 
SalaryRanges.Max FROM Employees INNER JOIN SalaryRanges 
ON Employees.SalaryKey = SalaryRanges.SalaryKey 
ORDER BY SalaryRanges.Min; 
     

				Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
    
       

				String url = "jdbc:odbc:Grocery prices"; 
 Connection con = DriverManager.getConnection(url); 
    
     

				jdbc: 
          subprotocol: 
          subname
			

				jdbc:bark//doggie/elliott 
    
     

				jdbc:bark//doggie/elliot;UID=GoodDog;PWD=woof 
    
     

				// 
        从元数据中获得列数
    
        ResultSetMetaData rsmd; 
    rsmd = results.getMetaData(); 
    numCols = rsmd.getColumnCount(); 

    
     

				try 
 { 
 rsmd = results.getMetaData(); 
 numCols = rsmd.getColumnCount(); 
 boolean more = results.next(); 
 while (more) 
 { 
 for (i = 1; i <= numCols; i++) 
 System.out.print(results.getString(i)+" "); 
 System.out.println(); 
 more = results.next(); 
 } 
 results.close(); 
 } 
 catch(Exception e) 
 {System.out.println(e.getMessage());} 
    
     

				results = 
 dma.getTables(catalog, schema, tablemask, types[]); 
     

				con = DriverManager.getConnection(url); 
 // 获取数据库的元数据
        dma =con.getMetaData(); 
 // 将数据库中的表的名称转储出来
        String[] types = new String[1]; 
 types[0] = "TABLES"; // 设置查询类型
        // 请注意通配符是 
        % 符号（而不是
        “*”）
        results = dma.getTables(null, null, "%", types); 
    
     

				boolean more = results.next(); 
 while (more) 
 { 
 for (i = 1; i <= numCols; i++) 
 System.out.print(results.getString(i)+" "); 
 System.out.println(); 
 more = results.next(); 
 } 
    
     

				String query = "SELECT FoodName FROM Food;"; 
 ResultSet results; 
 try 
 { 
 Statement stmt = con.createStatement(); 
 results = stmt.executeQuery(query); 
 } 
 catch (Exception e) 
 {System.out.println("query exception");} 
    
     

				private void dumpResults(String head) 
 { 
 // 
        这是打印列标头和每列的内容的

        // 
        通用方法

        System.out.println(head); 
 try 
 { 
 // 
        从元数据中获取列数
 
        rsmd = results.getMetaData(); 
 numCols = rsmd.getColumnCount(); 
 // 
        打印列名
 
        for (i = 1; i<= numCols; i++) 
 System.out.print(rsmd.getColumnName(i)+" "); 
 System.out.println(); 
 // 
        打印列内容
 
        boolean more = results.next(); 
 while (more) 
 { 
 for (i = 1; i <= numCols; i++) 
 System.out.print(results.getString(i)+" "; 
 System.out.println(); 
 more = results.next(); 
 } 
 } 
 catch(Exception e) 
 {System.out.println(e.getMessage());} 
 } 

    
     

				import java.net.URL; 
 import java.sql.*; 
 import java.util.*; 
 class JdbcOdbc_test 
 { 
 ResultSet results; 
 ResultSetMetaData rsmd; 
 DatabaseMetaData dma; 
 Connection con; 
 int numCols, i; 
 //-- 
 public JdbcOdbc_test() 
 { 
 String url = "jdbc:odbc:Grocery prices"; 
 String query = "SELECT DISTINCTROW FoodName FROM Food " + "WHERE (FoodName like 'C%');"; 
 try 
 { 
 // 
        加载 JDBC-ODBC 桥驱动程序
 Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
 // 连接数据库
 con = DriverManager.getConnection(url); 
 // 获取数据库的元数据
 dma =con.getMetaData(); 
 System.out.println("Connected to:"+dma.getURL()); 
 System.out.println("Driver "+dma.getDriverName()); 
 // 将数据库中的表的名称转储出来
 String[] types = new String[1]; 
 types[0] = "TABLES"; 
 // 请注意通配符是 % 符号（而不是“*”）
 results = dma.getTables(null, null, "%", types); 
 dumpResults("--Tables--"); 
 results.close(); 
 } 
 catch (Exception e) 
 {System.out.println(e);} 
 // 获取表列的名称
 System.out.println("--Column Names--"); 
 try { 
 results = 
 dma.getColumns(null, null, "FoodPrice", null); 
 ResultSetMetaData rsmd = results.getMetaData(); 
 int numCols = rsmd.getColumnCount(); 
 while (results.next() ) 
 String cname = results.getString("COLUMN_NAME"); 
 System.out.print(cname + " "); 
 System.out.println(); 
 results.close(); 
 } 
 catch (Exception e) 
 {System.out.println(e);} 
 // 列出一个列的内容 -- 这是一个查询
 try { 
 Statement stmt = con.createStatement(); 
 results = 
 stmt.executeQuery("SELECT FOODNAME FROM FOOD;"); 
 } 
 catch (Exception e) 
 {System.out.println("query exception");} 
 dumpResults("--Contents of FoodName column--"); 
 // 尝试实际的 SQL 语句
 try 
 { 
 Statement stmt = con.createStatement(); 
 results = stmt.executeQuery(query); 
 } 
 catch (Exception e) 
 {System.out.println("query exception");} 
 dumpResults("--Results of Query--"); 
 } 
    
     

				C:\Projects\objectJava\chapter19>java JdbcOdbc_test 
 Connected to:jdbc:odbc:Grocery prices 
 Driver JDBC-ODBC Bridge (ODBCJT32.DLL) 
 --Tables-- 
 TABLE_QUALIFIER TABLE_OWNER TABLE_NAME TABLE_TYPE REMARKS 
 groceries null Food TABLE null 
 groceries null FoodPrice TABLE null 
 groceries null Stores TABLE null 
 --Column Names-- 
 FSKey StoreKey FoodKey Price 
 --Contents of FoodName column-- 
 FOODNAME 
 Apples 
 Oranges 
 Hamburger 
 Butter 
 Milk 
 Cola 
 Green beans 
 --Results of Query-- 
 FoodName 
 Cola 
    
     

				class resultSet 
 { 
 // 
        这个类是 
        JDBC ResultSet 
        对象的更高级抽象
 
        ResultSet rs; 
 ResultSetMetaData rsmd; 
 int numCols; 
 public resultSet(ResultSet rset) 
 { 
 rs = rset; 
 try 
 { 
 // 
        同时获取元数据和列数
 
        rsmd = rs.getMetaData(); 
 numCols = rsmd.getColumnCount(); 
 } 
 catch (Exception e) 
 {System.out.println("resultset error"
 +e.getMessage());} 
 } 
 //-- 
 public String[] getMetaData() 
 { 
 // 
        返回包含所有列名或其他元数据的
 
        // 
        一个数组
 
        String md[] = new String[numCols]; 
 try 
 { 
 for (int i=1; i<= numCols; i++) 
 md[i-1] = rsmd.getColumnName(i); 
 } 
 catch (Exception e) 
 {System.out.println("meta data error"+ 
 e.getMessage());} 
 return md; 
 } 
 //-- 
 public boolean hasMoreElements() 
 { 
 try{ 
 return rs.next(); 
 } 
 catch(Exception e){return false;} 
 } 
 //-- 
 public String[] nextElement() 
 { 
 // 
        将行的内容复制到字符串数组中
 
        String[] row = new String[numCols]; 
 try 
 { 
 for (int i = 1; i <= numCols; i++) 
 row[i-1] = rs.getString(i); 
 } 
 catch (Exception e) 
 {System.out.println("next element error"+ 
 e.getMessage());} 
 return row; 
 } 
 //-- 
 public String getColumnValue(String columnName) 
 { 
 String res = ""; 
 try 
 { 
 res = rs.getString(columnName); 
 } 
 catch (Exception e) 
 {System.out.println("Column value error:"+ 
 columnName+e.getMessage());} 
 return res; 
 } 
 //-- 
 public String getColumnValue(int i) 
 { 
 String res = ""; 
 try 
 { 
 res = rs.getString(i); 
 } 
 catch (Exception e) 
 {System.out.println("Column value error:"+ 
 columnName+e.getMessage());} 
 return res; 
 } 
 //-- 
 public void finalize() 
 { 
 try{rs.close();} 
 catch (Exception e) 
 {System.out.println(e.getMessage());} 
 } 
 } 
    
     

				ResultSet results = .. // 
        按通常的方法获得
        ResultsSet 
 // 
        利用它创建一个更有用的对象

        resultSet rs = new resultSet(results); 
    
     

				class Database 
 { 
 // 
        这是一个将 
        JDBC 
        数据库的所有功能封装在单个对象中的类

        Connection con; 
 resultSet results; 
 ResultSetMetaData rsmd; 
 DatabaseMetaData dma; 
 String catalog; 
 String types[]; 
 public Database(String driver) 
 { 
 types = new String[1]; 
 types[0] = "TABLES"; // 
        初始化类型
 
        try{Class.forName(driver);} // 
        加载 
        JDBC-ODBC 
        桥驱动程序
 
        catch (Exception e) 
 {System.out.println(e.getMessage());} 
 } 
 //-- 
 public void Open(String url, String cat) 
 { 
 catalog = cat; 
 try {con = DriverManager.getConnection(url); 
 dma =con.getMetaData(); // 
        获取元数据
 
        } 
 catch (Exception e) 
 {System.out.println(e.getMessage());} 
 } 
 //-- 
 public String[] getTableNames() 
 { 
 String[] tbnames = null; 
 Vector tname = new Vector(); 
 // 
        将表名添加到一个 Vector 
        中，
 
        // 
        因为我们不知道有多少个表
 
        try { 
 results = 
 new resultSet(dma.getTables(catalog, null, 
 "%", types)); 
 while (results.hasMoreElements()) 
 tname.addElement(results.getColumnValue("TABLE_NAME")); 
 } 
 catch (Exception e) {System.out.println(e);} 
 // 
        将表名复制到一个 
        String 
        数组中
 
        tbnames = new String[tname.size()]; 
 for (int i=0; i< tname.size(); i++) 
 tbnames[i] = (String)tname.elementAt(i); 
 return tbnames; 
 } 
 //-- 
 public String[] getTableMetaData() 
 { 
 // 
        返回表类型的信息
 
        results = null; 
 try{ 
 results = 
 new resultSet(dma.getTables(catalog, null, 
 "%", types)); 
 } 
 catch (Exception e) 
 {System.out.println(e.getMessage());} 
 return results.getMetaData(); 
 } 
 //-- 
 public String[] getColumnMetaData(String tablename) 
 { 
 // 
        返回一个列的数据
 
        results = null; 
 try { 
 results = 
 new resultSet(dma.getColumns(catalog, null, 
 tablename, null)); 
 } 
 catch (Exception e) 
 {System.out.println(e.getMessage());} 
 return results.getMetaData(); 
 } 
 //-- 
 public String[] getColumnNames(String table) 
 { 
 // 
        返回一个列名数组
 
        String[] tbnames = null; 
 Vector tname = new Vector(); 
 try { 
 results = 
 new resultSet(dma.getColumns(catalog, null, 
 table, null)); 
 while (results.hasMoreElements() ) 
 tname.addElement(results.getColumnValue("COLUMN_NAME")); 
 } 
 catch (Exception e) {System.out.println(e);} 
 tbnames = new String[tname.size()]; 
 for (int i=0; i< tname.size(); i++) 
 tbnames[i] = (String)tname.elementAt(i); 
 return tbnames; 
 } 
 //-- 
 public String getColumnValue(String table, 
 String columnName) 
 { 
 // 
        返回给定列的值 
        String res = null; 
 try 
 { 
 if (table.length()>0) 
 results = 
 Execute("Select " + columnName + 
 " from " + table + 
 " order by "+columnName); 
 if (results.hasMoreElements()) 
 res = results.getColumnValue(columnName); 
 } 
 catch (Exception e) 
 {System.out.println("Column value error" + 
 columnName+ e.getMessage());} 
 return res; 
 } 
 //-- 
 public String getNextValue(String columnName) 
 { 
 // 
        使用存储的 
        resultSet 
 // 
        返回该列的下一个值
 
        String res = ""; 
 try 
 { 
 if (results.hasMoreElements()) 
 res = results.getColumnValue(columnName); 
 } 
 catch (Exception e) 
 {System.out.println("next value error"+ 
 columnName+ e.getMessage());} 
 return res; 
 } 
 //-- 
 public resultSet Execute(String sql) 
 { 
 // 
        对此数据库执行一个 
        SQL 
        查询
 
        results = null; 
 try 
 { 
 Statement stmt = con.createStatement(); 
 results = new resultSet(stmt.executeQuery(sql)); 
 } 
 catch (Exception e) 
 {System.out.println("execute error"+ 
 e.getMessage());} 
 return results; 
 } 
 } 
    
     

				public void itemStateChanged(ItemEvent e) 
 { 
 Object obj = e.getSource(); 
 if (obj == Tables) // 
        放入列名
 
        showColumns(); 
 if (obj == Columns) // 
        放入列的内容
 
        showData(); 
 } 
 //-- 
 private void loadList(List list, String[] s) 
 { 
 // 
        清除并填充指定的列表框
 
        list.removeAll(); 
 for (int i=0; i< s.length; i++) 
 list.add(s[i]); 
 } 
 //-- 
 private void showColumns() 
 { 
 // 
        显示列名
 
        String cnames[] = 
 db.getColumnNames(Tables.getSelectedItem()); 
 loadList(Columns, cnames); 
 } 
 //-- 
 private void showData() 
 { 
 String colname = Columns.getSelectedItem(); 
 String colval = 
 db.getColumnValue(Tables.getSelectedItem(), 
 colname); 
 Data.setVisible(false); 
 Data.removeAll(); 
 Data.setVisible(true); 
 colval = 
 db.getNextValue(Columns.getSelectedItem()); 
 while (colval.length()>0) 
 { 
 Data.add(colval); 
 colval = 
 db.getNextValue(Columns.getSelectedItem()); 
 } 
 } 
    
     

				String queryText = 
"SELECT DISTINCTROW FoodName, StoreName, Price "+ 
"FROM (Food INNER JOIN FoodPrice ON "+ 
"Food.FoodKey = FoodPrice.FoodKey) " + 
"INNER JOIN Stores ON "+ 
"FoodPrice.StoreKey = Stores.StoreKey "+ 
"WHERE (((Food.FoodName)=\'Oranges\')) "+ 
" ORDER BY FoodPrice.Price;"; 
    
     

				public void actionPerformed(ActionEvent e) 
 { 
 Object obj = e.getSource(); 
 if (obj == Quit) 
 System.exit(0); 
 if (obj == Search) 
 clickedSearch(); 
 } 
 //-- 
 private void clickedSearch() 
 { 
 resultSet rs = db.Execute(query.getText()); 
 String cnames[] = rs.getMetaData(); 
 queryDialog q = new queryDialog(this, rs); 
 q.show(); 
 } 
    
     

				private void makeTables() 
 { 
 // 
        将每一行放入一个 
        String 
        数组中，并将

        // 
        这些字符串数组全部放入一个 
        Vector 
        中
 
        tables = new Vector(); 
 String t[] = results.getMetaData(); 
 tables.addElement( t); 
 while (results.hasMoreElements()) 
 tables.addElement(results.nextElement()); 
 } 
    
     

				public void paint(Graphics g) 
 { 
 String s[]; 
 int x=0; 
 // 
        计算字体的高度

        int y =g.getFontMetrics().getHeight(); 
 // 
        估算列的高度

        int deltaX = (int)1.5f* 
 (g.getFontMetrics().stringWidth("wwwwwwwwwwwwww")); 
 // 
        遍历表矢量

        for (int i=0; i< tables.size(); i++) 
 { 
 s = (String[])tables.elementAt(i); 
 // 
        绘制字符串数组中的每一行
 
        for (int j =0; j< s.length; j++) 
 { 
 String st= s[j]; 
 g.drawString(st, x, y); 
 x += deltaX; // 
        移到下一列
 
        } 
 x = 0; // 
        开始一个新行
 
        y += g.getFontMetrics().getHeight(); 
 // 
        列标签与列数据之间的额外空间
 
        if (i == 0) y += g.getFontMetrics().getHeight(); 
 } 
 }