sql.java

ATM系统分为前台和后台

package oo;
import java.sql.*;
public class Sql {
	
	private Connection conn=null;
	private Statement st=null;
	private ResultSet rs=null;
	private PreparedStatement psmt=null;
	private DatabaseMetaData meta;
	public static boolean scrolling=false;
	
	public Sql(){
		try{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
	        //conn=DriverManager.getConnection("jdbc:odbc:bank");
		}catch(ClassNotFoundException ex){
			ex.printStackTrace();
		}
	}
	public Connection getConn(){
		try{
		
			//conn=DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=bank.mdb");
				
			String dbURL = "jdbc:odbc:bank"; 
		    conn = DriverManager.getConnection(dbURL);  
			   
		}catch(SQLException ex){
			ex.printStackTrace();
		}
		return conn;
	}
	public ResultSet executeQuery(String sql){
		try
        {
			meta=conn.getMetaData();
         if(meta.supportsResultSetType(ResultSet.TYPE_SCROLL_INSENSITIVE)){
        	 st = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
        	 scrolling=true;
         }else{
			st = conn.createStatement();
			scrolling=false;
         }
			rs = st.executeQuery(sql);
          
         } catch (SQLException e)  {
            System.out.println("数据库查询异常！");
         }
        return rs;
	}
    public void executeUpdate(String sql){
    	 try
         {
              st=conn.createStatement();
              st.executeUpdate(sql);
         } catch (SQLException e)
         {
        	 System.out.println("数据库更新异常！") ;
         }
    }
//  更新,插入数据并返回是否成功
    public boolean executeUpdateSQL(String sql) {
        
        int i = 0;
        try {
            Statement stmt = conn.createStatement();
            i = stmt.executeUpdate(sql);
            stmt.close();
           
        } catch (SQLException ex) {
            javax.swing.JOptionPane.showMessageDialog(null,
                    ex.getMessage().toString());
            return false;
        }
        if (i > 0) {
            return true;
        } else {
            return false;
        }
    }
    public void closeDB(){
    	try{
    		
    		if(st!=null)
    			st.close();
    		if(conn!=null)
    			conn.close();
    	 /*   if(rs!=null)
    	    	rs.close();*/
    	}catch(Exception ex){
    		return ;
    	}
    }
    public  boolean isValid(Connection conn,String user,String pass){
		
		
		String sql="select * from admin where user=? and pass=?";
		boolean temp=false;
		try{
			psmt=conn.prepareStatement(sql);
			psmt.setString(1, user);
			psmt.setString(2,pass);
			rs=psmt.executeQuery();
			if(rs.next())
				temp=true;
			else
				temp=false;
			psmt.close();
		}catch(Exception ex){
			ex.printStackTrace();
		}
		return temp;
	}
 public  boolean isValid1(Connection conn,String cardID,String pass){
		
		
		String sql="select * from cardInfo where cardID=? and pass=?";
		boolean temp=false;
		try{
			psmt=conn.prepareStatement(sql);
			psmt.setString(1, cardID);
			
			psmt.setString(2,pass);
			rs=psmt.executeQuery();
			if(rs.next())
				temp=true;
			else
				temp=false;
			psmt.close();
		}catch(Exception ex){
			ex.printStackTrace();
		}
		return temp;
	}
  public String[] getTableNames()throws SQLException{
    	rs=meta.getTables(null, null, null, new String[]{"TABLE"});
    	String[] aa=null;int i=0;
    	while(rs.next()){
    		aa[i]=rs.getString(3);
    		i++;
    	}
    	return aa;	
    }
   /* public void showRow(ResultSet rs)throws SQLException{
    	
    }
    public void showPreviousRow(){
    	try{
    		if(rs==null || rs.isFirst()) return ;
    		rs.previous();
    		
    	}catch(SQLException ex){
    		ex.printStackTrace();
    	}
    	
    }*/

}