conndb.java

一个图文并茂的Jsp+MSSQL+TOMCAT的图书超市

package com.bwm.beans;

import java.sql.*;

public class connDB{
      Connection conn=null;
      Statement  stmt=null;
      ResultSet    rs=null;
      
      public connDB(){
       try{
           Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
          } catch(java.lang.ClassNotFoundException e){
               System.err.println(e.getMessage());
          }

      }
    /* 执行查询操作，返回值为ResultSet */
      public ResultSet executeQuery(String sql){
      try{
       conn=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=business;user=sa;password=");
       stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                       ResultSet.CONCUR_READ_ONLY);
        rs=stmt.executeQuery(sql);
      
     	 }catch(SQLException ex){
      		System.err.println(ex.getMessage());
 		}
          return rs;
       }

     /* 执行更新操作，返回值为int*/

       public int executeUpdate(String sql){
       int result=0;
       try{
       conn=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=business;user=sa;password=");
       stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                       ResultSet.CONCUR_READ_ONLY);
       result=stmt.executeUpdate(sql);
	}catch(SQLException ex){
                result=0;
		}
 	return result;
       }

     /*执行更新操作并返回自动编号的值，返回值为int*/
     
       public int executeUpdate_id(String sql){
	int result=0;
	try{
       conn=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=business;user=sa;password=");
       stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                       ResultSet.CONCUR_READ_ONLY);
       result=stmt.executeUpdate(sql);
	String ID="select @@IDENTITY as id";
  	 rs=stmt.executeQuery(ID);
         if(rs.next()){
 		int autoID=rs.getInt("id");
 		result=autoID;
		}
	
	}catch(SQLException ex){
	result=0;
	}
        return result;
	}

    /*关闭数据库连接，无返回值*/

	public void close(){
	try{
	   if(rs!=null)rs.close();
		}catch(Exception e){
                                    e.printStackTrace(System.err);
					}
 	try{
 	   if(stmt!=null)stmt.close();
		}catch(Exception e){
					e.printStackTrace(System.err);
					}
        try{
	   if(conn!=null){conn.close();}
		}catch(Exception e){e.printStackTrace(System.err);
					}

 	}

}