query.java

用户需要注册

//查询user数据库
import java.sql.*;

public class Query {
	 public static boolean select(String name)
     {//查询用户名是否存在
		 Connection conn = null;
	        String username="root";
	   	 	String password="111111";
	   	 	String url = "jdbc:mysql://localhost:3306/shoppingmall";
	   	 try{  
	   		 //-------------加载驱动-------------------------   
	   		 Class.forName("org.gjt.mm.mysql.Driver").newInstance();
	   		 System.out.println("Query:Success loading Mysql Driver!");
	   	 }
	   	 catch(Exception e){
	   		 System.out.println("Error loading Mysql Driver!");
	   	 }
	   	 try{   
	   		 conn = DriverManager.getConnection(url,username,password);
	   		// System.out.println("Success connect Mysql Database!"); 
	   	}
		 catch(SQLException e){
			 System.out.println(e.getMessage());
	  }
         Statement stmt = null;
         ResultSet rs = null;
         try
         {
             stmt = conn.createStatement();
             rs = stmt.executeQuery("select * from user where name='"+name+"'");//对数据库的查询
             while (rs.next())
             {
            	 return true;
             }
             //conn.commit();
         }
         catch (SQLException e)
         {
             e.printStackTrace();
         }
         finally
         {
             if (null != conn)
             {
                 try
                 {
                     conn.close();
                 }
                 catch (SQLException e)
                 {
                     e.printStackTrace();
                 }
             }
         }
         return false;
     }
	 public static boolean selectShopKeeper(String name)
	 {//查询是否已注册店主
		 Connection conn = null;
	        String username="root";
	   	 	String password="111111";
	   	 	String url = "jdbc:mysql://localhost:3306/shoppingmall";
	   	 try{  
	   		 //-------------加载驱动-------------------------   
	   		 Class.forName("org.gjt.mm.mysql.Driver").newInstance();
	   		 System.out.println("Query:Success loading Mysql Driver!");
	   	 }
	   	 catch(Exception e){
	   		 System.out.println("Error loading Mysql Driver!");
	   	 }
	   	 try{   
	   		 conn = DriverManager.getConnection(url,username,password);
	   		// System.out.println("Success connect Mysql Database!"); 
	   	}
		 catch(SQLException e){
			 System.out.println(e.getMessage());
	  }
         Statement stmt = null;
         ResultSet rs = null;
         String s=null;
         try
         {
             stmt = conn.createStatement();
             rs = stmt.executeQuery("select shopname from user where name='"+name+"'");//对数据库的查询
             while(rs.next())
             {
            	 s = rs.getString("shopname");
             }
             if(s!=null)
            	 return true;
             //conn.commit();
         }
         catch (SQLException e)
         {
             e.printStackTrace();
         }
         finally
         {
             if (null!= conn)
             {
                 try
                 {
                     conn.close();
                 }
                 catch (SQLException e)
                 {
                     e.printStackTrace();
                 }
             }
         }
		 return false;
	 }
	 public static boolean state(String name){
		 //查询店主状态是否为登录
		 Connection conn = null;
	        String username="root";
	   	 	String password="111111";
	   	 	String url = "jdbc:mysql://localhost:3306/shoppingmall";
	   	 try{  
	   		 //-------------加载驱动-------------------------   
	   		 Class.forName("org.gjt.mm.mysql.Driver").newInstance();
	   		 System.out.println("Query:Success loading Mysql Driver!");
	   	 }
	   	 catch(Exception e){
	   		 System.out.println("Error loading Mysql Driver!");
	   	 }
	   	 try{   
	   		 conn = DriverManager.getConnection(url,username,password);
	   		// System.out.println("Success connect Mysql Database!"); 
	   	}
		 catch(SQLException e){
			 System.out.println(e.getMessage());
	  }
      Statement stmt = null;
      ResultSet rs = null;
      String s=null;
      try
      {
          stmt = conn.createStatement();
          rs = stmt.executeQuery("select state from user where name='"+name+"'");//对数据库的查询
          while(rs.next())
          {
         	 s = rs.getString("state").trim();
          }
          int st = Integer.parseInt(s);
          if(st==1)
         	 return true;
          //conn.commit();
      }
      catch (SQLException e)
      {
          e.printStackTrace();
      }
      finally
      {
          if (null!= conn)
          {
              try
              {
                  conn.close();
              }
              catch (SQLException e)
              {
                  e.printStackTrace();
              }
          }
      }
		 return false;
	 }

}