[转]用Lucene.net对数据库建立索引及搜索

用Lucene.net对数据库建立索引及搜索。

简要说一下过程,首先是从数据库里取出内容,在磁盘上建立了索引文件。之后每次进行数据检索时从索引文件中检索数据。


 
字段名称 字段类型 字段含义
id    varchar 编号
title vachar 标题
content text 内容
aspx文件:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="TestLLLL._Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>使用Lucene.net建立简单的数据库搜索程序</title>
    <meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
    <meta content="C#" name="CODE_LANGUAGE">
    <meta content="JavaScript" name="vs_defaultClientScript">
    <meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
</head>
<body ms_positioning="GridLayout">
    <form id="Form1" method="post" runat="server">
    <table width="100%" border="0">
        <tr>
            <td>
                 
                <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
 <asp:Button ID="Search" runat="server"
                    Text="搜索" onclick="Search_Click"></asp:Button>
            </td>
        </tr>
    </table>
    <table width="100%" border="0">
        <tr>
            <td>
                <asp:DataGrid ID="SearGrid" runat="server" AutoGenerateColumns="False">
                    <Columns>
                        <asp:TemplateColumn>
                            <HeaderTemplate>
                                搜索结果:
                            </HeaderTemplate>
                            <ItemTemplate>
                                <table width="100%" border="0">
                                    <tr>
                                        <td>
                                            id:<%# DataBinder.Eval(Container.DataItem,"id") %>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td>
                                            标题:
                                            <%# DataBinder.Eval(Container.DataItem,"title") %>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td>
                                            内容:
                                            <%# DataBinder.Eval(Container.DataItem,"content") %>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td>
                                             
                                        </td>
                                    </tr>
                                </table>
                            </ItemTemplate>
                        </asp:TemplateColumn>
                    </Columns>
                </asp:DataGrid>
            </td>
        </tr>
    </table>
    </form>
</body>
</html>
 
 
cs源文件
namespace TestLLLL
{
    public partial class _Default : System.Web.UI.Page
    {
        string connstr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Server.MapPath("~/db1.mdb");
        protected void Page_Load(object sender, EventArgs e)
        {
            //OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Server.MapPath("~/check.mdb"));       
            if (!IsPostBack)
            {
                //打开数据库表
                OleDbDataReader myred = OpenTable();
                //建立索引
                IndexWriter writer = CreateIndex(myred);
            }
        }

        public OleDbDataReader OpenTable()
        {
            OleDbConnection mycon = new OleDbConnection(connstr);
            mycon.Open();
            OleDbCommand mycom = new OleDbCommand("select id,title,content from userblog order by id", mycon);
            return mycom.ExecuteReader();
        }

        public IndexWriter CreateIndex(OleDbDataReader myred)
        {
            IndexWriter writer = new IndexWriter(@"c:/index/", new ChineseAnalyzer(), true);
            try
            {
                //建立索引字段
                while (myred.Read())
                {
                    Document doc = new Document();
                    doc.Add(Field.Keyword("id", myred["id"].ToString()));
                    doc.Add(Field.Text("title", myred["title"].ToString()));
                    doc.Add(Field.Text("content", myred["content"].ToString()));
                    writer.AddDocument(doc);

                }
                writer.Optimize();
                writer.Close();
            }
            catch (Exception e)
            {
                Response.Write(e);
            }
            return writer;
        }

        public Hits seacher(string queryKey, string queryContent)
        {
            Hits hits = null;
            try
            {
                IndexSearcher mysea = new IndexSearcher("c:/index/");
                Query query = QueryParser.Parse(queryContent, queryKey, new ChineseAnalyzer());
                hits = mysea.Search(query);
            }
            catch (Exception e)
            {
                Response.Write(e);
            }
            return hits;
        }

        protected void Search_Click(object sender, EventArgs e)
        {
            DataRow myrow;
            DataTable mytab = new DataTable();
            mytab.Columns.Add("id");
            mytab.Columns.Add("title");
            mytab.Columns.Add("content");
            mytab.Clear();




            Hits myhit = seacher("title", TextBox1.Text);
            Document doc;
            if (myhit != null)
            {
                for (int i = 0; i < myhit.Length(); i++)
                {
                    doc = myhit.Doc(i);
                    myrow = mytab.NewRow();
                    myrow[0] = doc.Get("id").ToString();
                    myrow[1] = doc.Get("title").ToString();
                    myrow[2] = doc.Get("content").ToString();

                    mytab.Rows.Add(myrow);
                    myrow.AcceptChanges();
                }
            }

            this.SearGrid.DataSource = mytab;
            this.SearGrid.DataBind();

        }
    }
}
原文地址:https://www.cnblogs.com/cxeye/p/2338904.html