以C#为前端,SQL Server 2000层次数据查询是如何实现的呢?本文我们主要就介绍这部分内容,接下来就让我们一起来了解一下这一过程吧。

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//层次数据实体
- public class ComLevelDataEntity
 - {
 - public ComLevelDataEntity()
 - {
 - searchLevel = 0;
 - startWithRoot = true;
 - dataObjectAlias = "t";
 - }
 - private int searchLevel;
 - ///
 - /// 查询层次
 - ///
 - public int SearchLevel
 - {
 - get { return searchLevel; }
 - set { searchLevel = value; }
 - }
 - private string dataObjectAlias;
 - ///
 - /// 别名
 - ///
 - public string DataObjectAlias
 - {
 - get { return dataObjectAlias; }
 - set { dataObjectAlias = value; }
 - }
 - private string protasis;
 - ///
 - /// 条件从句
 - ///
 - public string Protasis
 - {
 - get
 - {
 - return string.IsNullOrEmpty(protasis) ? string.Empty : string.Concat(" and ", protasis);
 - }
 - set { protasis = value; }
 - }
 - private bool startWithRoot;
 - ///
 - /// 整树搜索
 - ///
 - public bool StartWithRoot
 - {
 - get { return startWithRoot; }
 - set { startWithRoot = value; }
 - }
 - private string dataObjectName;
 - ///
 - /// 数据对象名称
 - ///
 - public string DataObjectName
 - {
 - get { return dataObjectName; }
 - set { dataObjectName = value; }
 - }
 - private int cascadeLevel;
 - ///
 - /// 层级
 - ///
 - public int CascadeLevel
 - {
 - get { return cascadeLevel; }
 - set { cascadeLevel = value; }
 - }
 - private string displayFieldName;
 - ///
 - /// 显示字段名称
 - ///
 - public string DisplayFieldName
 - {
 - get { return displayFieldName; }
 - set { displayFieldName = value; }
 - }
 - private string keyFieldName;
 - ///
 - /// 键值字段名称
 - ///
 - public string KeyFieldName
 - {
 - get { return keyFieldName; }
 - set { keyFieldName = value; }
 - }
 - private string displayFieldValue;
 - ///
 - /// 显示字段值
 - ///
 - public string DisplayFieldValue
 - {
 - get { return displayFieldValue; }
 - set { displayFieldValue = value; }
 - }
 - private string keyFieldValue;
 - ///
 - /// 键值字段值
 - ///
 - public string KeyFieldValue
 - {
 - get { return keyFieldValue; }
 - set { keyFieldValue = value; }
 - }
 - private string levelFieldName;
 - ///
 - /// 层次字段名称
 - ///
 - public string LevelFieldName
 - {
 - get { return levelFieldName; }
 - set { levelFieldName = value; }
 - }
 - private string levelFieldValue;
 - ///
 - /// 层次字段值
 - ///
 - public string LevelFieldValue
 - {
 - get { return levelFieldValue; }
 - set { levelFieldValue = value; }
 - }
 - }
 
//sqlserver2000存储过程
- if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[sp_gettreedata]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
 - drop procedure [dbo].[sp_gettreedata]
 - GO
 - SET QUOTED_IDENTIFIER ON
 - GO
 - SET ANSI_NULLS ON
 - GO
 - CREATE PROCEDURE [dbo].[sp_gettreedata]
 - (@table_name nvarchar(50), @id nvarchar(50), @name nvarchar(50), @parent_id nvarchar(50), @startId nvarchar(50), @maxlevel int)
 - AS
 - declare @v_id nvarchar(50)
 - declare @v_level int
 - declare @sql nvarchar(500)
 - declare @v_maxlevel int
 - begin
 - create table #temp (id nvarchar(50),name nvarchar(50),parent_id nvarchar(50))
 - create table #t1 (id nvarchar(50),name nvarchar(50),parent_id nvarchar(50),level int)
 - delete from com_temp
 - set @sql='insert into #temp select '+@id+','+@name+','+@parent_id +' from '+@table_name
 - exec sp_executesql @sql
 - set @v_level=1
 - set @v_id=@startId
 - set @v_maxlevel = @maxlevel
 - insert #t1 select a.id,a.name,a.parent_id,@v_level from #temp a where a.id=@v_id
 - while @@rowcount>0
 - begin
 - set @v_level=@v_level+1
 - insert #t1 select a.id,a.name,a.parent_id,@v_level
 - from #temp a where a.parent_id in
 - (select id from #t1 where level=@v_level-1)
 - end
 - insert into Com_TEMP select a.level,a.id,a.name,a.parent_id,b.name parent_name
 - from #t1 a left outer join #temp b
 - on a.parent_id = b.id
 - where a.level <= @maxlevel
 - order by a.level
 - select * from Com_TEMP order by dbo.f_getidpath(id)
 - end
 - GO
 - SET QUOTED_IDENTIFIER OFF
 - GO
 - SET ANSI_NULLS ON
 - GO
 
//sqlserver2000函数
- if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_getidpath]') and xtype in (N'FN', N'IF', N'TF'))
 - drop function [dbo].[f_getidpath]
 - GO
 - SET QUOTED_IDENTIFIER OFF
 - GO
 - SET ANSI_NULLS ON
 - GO
 - CREATE function f_getidpath(@id char(36))
 - returns varchar(8000)
 - as
 - begin
 - declare @re varchar(8000),@pid char(36)
 - set @re=@id
 - select @pid=parent_id from com_temp where id=@id
 - while @@rowcount> 0
 - select @re=@pid + '.'+ @re,@pid=parent_id from com_temp where id=@pid
 - return(@re)
 - end
 - GO
 - SET QUOTED_IDENTIFIER OFF
 - GO
 - SET ANSI_NULLS ON
 - GO
 
//数据访问层方法
- public ComLevelDataEntity[] PrepareHierarchyData(ComLevelDataEntity entity)
 - {
 - System.Data.SqlClient.SqlParameter[] parameters = new System.Data.SqlClient.SqlParameter[6];
 - parameters[0] = new SqlParameter();
 - parameters[0].ParameterName = "@table_name";
 - parameters[0].Size = 50;
 - parameters[0].SqlDbType = System.Data.SqlDbType.VarChar;
 - parameters[1] = new SqlParameter();
 - parameters[1].ParameterName = "@id";
 - parameters[1].Size = 50;
 - parameters[1].SqlDbType = System.Data.SqlDbType.VarChar;
 - parameters[2] = new SqlParameter();
 - parameters[2].ParameterName = "@name";
 - parameters[2].Size = 50;
 - parameters[2].SqlDbType = System.Data.SqlDbType.VarChar;
 - parameters[3] = new SqlParameter();
 - parameters[3].ParameterName = "@parent_id";
 - parameters[3].Size = 50;
 - parameters[3].SqlDbType = System.Data.SqlDbType.VarChar;
 - parameters[4] = new SqlParameter();
 - parameters[4].ParameterName = "@startId";
 - parameters[4].Size = 50;
 - parameters[4].SqlDbType = System.Data.SqlDbType.VarChar;
 - parameters[5] = new SqlParameter();
 - parameters[5].ParameterName = "@maxlevel";
 - parameters[5].SqlDbType = System.Data.SqlDbType.Int;
 - string spName = "sp_gettreedata";
 - if (entity.SearchLevel <= 0)
 - {
 - parameters[0].Value = entity.DataObjectName;
 - parameters[1].Value = entity.KeyFieldName;
 - parameters[2].Value = entity.DisplayFieldName;
 - parameters[3].Value = entity.LevelFieldName;
 - parameters[4].Value = entity.KeyFieldValue;
 - parameters[5].Value = 100;
 - }
 - else
 - {
 - parameters[0].Value = entity.DataObjectName;
 - parameters[1].Value = entity.KeyFieldName;
 - parameters[2].Value = entity.DisplayFieldName;
 - parameters[3].Value = entity.LevelFieldName;
 - parameters[4].Value = entity.KeyFieldValue;
 - parameters[5].Value = entity.SearchLevel;
 - }
 - List
 results = new List (); - IDbConnection connection = IDALProvider.IDAL.PopConnection();
 - IDataReader sqlReader = IDALProvider.IDAL.ExecuteReader(connection,spName, parameters);
 - while (sqlReader.Read())
 - {
 - ComLevelDataEntity result = new ComLevelDataEntity();
 - if (!sqlReader.IsDBNull(0))
 - result.CascadeLevel = (int)sqlReader.GetInt32(0);
 - if (!sqlReader.IsDBNull(1))
 - result.KeyFieldValue = sqlReader.GetString(1);
 - if (!sqlReader.IsDBNull(2))
 - result.DisplayFieldValue = sqlReader.GetString(2);
 - if (!sqlReader.IsDBNull(3))
 - result.LevelFieldValue = sqlReader.GetString(3);
 - result.DataObjectName = entity.DataObjectName;
 - result.DisplayFieldName = entity.DisplayFieldName;
 - result.LevelFieldName = entity.LevelFieldName;
 - result.KeyFieldName = entity.KeyFieldName;
 - results.Add(result);
 - }
 - sqlReader.Close();
 - IDALProvider.IDAL.PushConnection(connection);
 - return results.ToArray();
 - }
 
//前端调用代码
- ComLevelDataEntity entity = new ComLevelDataEntity();
 - entity.DataObjectName = "COM_DEPART";
 - entity.DataObjectAlias = "t";
 - entity.StartWithRoot = true;
 - entity.KeyFieldName = "id";
 - entity.LevelFieldName = "parent_id";
 - entity.DisplayFieldName = "name";
 - entity.KeyFieldValue = SystemLogic.CurrentUser.DATA_ORGANISE_ID;
 - ComLevelDataEntity[] results = IDALProvider.IDAL.PrepareHierarchyData(entity);
 - this.tvTree.DataSource = results;
 - this.tvTree.DataBind();
 
关于以C#为前端,SQL Server 2000层次数据查询的实现方法就介绍到这里了,希望本次的介绍能够对您有所收获!
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