package com.jiang.DB;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import com.sun.rowset.CachedRowSetImpl;
import javax.sql.RowSet;
import javax.sql.rowset.CachedRowSet;
import java.sql.ResultSet;
public class DBop {
	
     public static boolean save(String sql){
    	 DB db=new DB();
    	 Connection conn=db.getConnection();
    	 PreparedStatement pstm=null;
    	 try {
			pstm=conn.prepareStatement(sql);
			return pstm.execute();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return false;
     }
     
     public static RowSet search(String sql){
    	 DB db=new DB();
    	 Connection conn=db.getConnection();
    	 PreparedStatement pstm=null;
    	 try{
    		 pstm=conn.prepareStatement(sql);
    		 ResultSet rs=pstm.executeQuery();
    		 CachedRowSet crs=new CachedRowSetImpl();
		     crs.populate(rs);
			 return crs;
    	 }catch(Exception e){
    		 e.printStackTrace();
    		 return null;
    	 }finally{
    		 if(pstm!=null){
    			 try {
					pstm.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				if(conn!=null){
					try {
						conn.close();
					} catch (SQLException e) {
						System.out.println("关闭数据库链接时出现问题.....");
						e.printStackTrace();
					}
				}
    		 }
    	 }
     }
     
     public static int getNum(String tableName,String where){
    	 StringBuilder sb=new StringBuilder();
         sb.append("select count(*) as num from "+tableName);
         if(!"".equals(where)){
        	 sb.append(" ");
        	 if(where.startsWith("where")){
        		 sb.append(" "+where);
        	 }else{
        		 sb.append(" where "+where);
        	 }
         }
    	 DB db=new DB();
    	 Connection conn=db.getConnection();
    	 PreparedStatement pstm=null;
    	 try{
    		 pstm=conn.prepareStatement(sb.toString());
    		 ResultSet rs=pstm.executeQuery();
    		if(rs.next()){
    			 return rs.getInt("num");
    		}else{
    			return 0;
    		}
    	 }catch(Exception e){
    		 e.printStackTrace();
    		 return 0;
    	 }finally{
    		 if(pstm!=null){
    			 try {
					pstm.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				if(conn!=null){
					try {
						conn.close();
					} catch (SQLException e) {
						System.out.println("关闭数据库链接时出现问题.....");
						e.printStackTrace();
					}
				}
    		 }
    	 }
     }
}