1using System;
 2using System.Data;
 3using System.Data.OleDb;
 4using System.Collections;
 5using MessageBoard7.Classes;
 6
 7namespace MessageBoard7.AccessDAL
 8...{
 9    /**//// <summary>
10    /// Access中Messages表的数据操作类。
11    /// </summary>
12    
13    public class Messages : MessageBoard7.IDAL.IMessages
14    ...{
15        public Messages()
16        ...{
17            arrMessagesInfo = new ArrayList();
18        }
19        private ArrayList arrMessagesInfo;
20        private const string SQL_SELECT_MESSAGES = "SELECT MessageId,Content,PostTime FROM Messages ORDER BY MessageId DESC";
21        private const string SQL_INSERT_MESSAGES = "INSERT INTO Messages(Content,PostTime) values (@Content,@PostTime)";
22        private const string PARM_CONTENT = "@Content";
23        private const string PARM_POSTTIME = "@PostTime";
24        private const string SQL_SELECT_MESSAGES_TODAY = "SELECT MessageId,Content,PostTime FROM Messages WHERE PostTime>=@From AND PostTime<@To ORDER BY MessageId DESC";
25        private const string PARM_FROM = "@From";
26        private const string PARM_TO = "@To";
27        //获取所有留言
28        public MessagesInfo[] GetMessages()
29        ...{
30            OleDbDataReader dr = AccessHelper.ExecuteReader(AccessHelper.CONN_STRING, CommandType.Text, SQL_SELECT_MESSAGES, null);
31            while(dr.Read())
32            ...{
33                MessagesInfo messagesInfo = new MessagesInfo();
34                messagesInfo.MessageId = (int)dr["MessageId"];
35                messagesInfo.Content = (string)dr["Content"];
36                messagesInfo.PostTime = (DateTime)dr["PostTime"];
37                arrMessagesInfo.Add(messagesInfo);
38            }
39            return (MessagesInfo[])arrMessagesInfo.ToArray(typeof(MessagesInfo));
40        }
41        //获取当天留言
42        public MessagesInfo[] GetMessages(DateTime from, DateTime to)
43        ...{
44            ArrayList arrMessagesInfo = new ArrayList();
45            OleDbParameter[] parms = ...{
46                new OleDbParameter(PARM_FROM, OleDbType.Date),
47                new OleDbParameter(PARM_TO, OleDbType.Date)
48            };
49            parms[0].Value = from;
50            parms[1].Value = to;
51            //调用AccessHelper类的ExecuteReader方法当天所有留言信息
52            OleDbDataReader dr = AccessHelper.ExecuteReader(AccessHelper.CONN_STRING, CommandType.Text, SQL_SELECT_MESSAGES_TODAY, parms);
53            while(dr.Read())
54            ...{
55                MessagesInfo messagesInfo = new MessagesInfo();
56                messagesInfo.MessageId = (int)dr["MessageId"];
57                messagesInfo.Content = (string)dr["Content"];
58                messagesInfo.PostTime = (DateTime)dr["PostTime"];
59                arrMessagesInfo.Add(messagesInfo);
60            }
61            //将集合类型转化为数组
62            return (MessagesInfo[])arrMessagesInfo.ToArray(typeof(MessagesInfo));
63        }
64        //将单条留言信息存入数据库
65        public void SaveMessage(MessagesInfo messagesInfo)
66        ...{
67            string content = messagesInfo.Content.Trim();
68            DateTime dt = DateTime.Now;
69            OleDbParameter[] parms = ...{
70                new OleDbParameter(PARM_CONTENT, OleDbType.LongVarChar),
71                new OleDbParameter(PARM_POSTTIME, OleDbType.Date)
72            };
73            parms[0].Value = content;
74            parms[1].Value = dt;
75            AccessHelper.ExecuteNonQuery(AccessHelper.CONN_STRING, CommandType.Text, SQL_INSERT_MESSAGES, parms);
76        }
77        
78        
79        
80    }
81}
82