c#递归算法 C#关于递归的好文章?(3)

{

TreeNode Node = new TreeNode();

if (pNode == null)

{ //添加根节点

Node.Text = Row["Name"].ToString();

treeView1.Nodes.Add(Node);

AddTree(Row["Num"].ToString(), Node); //再次递归

}

else

{ //添加当前节点的子节点

Node.Text = Row["Name"].ToString();

pNode.Nodes.Add(Node);

AddTree(Row["Num"].ToString(), Node); //再次递归

}

}

}

DataSet ds = new DataSet();

private void Form2_Load(object sender, EventArgs e)

{

SqlConnection conn = new SqlConnection("server=.;database=test;uid=sa;pwd=;");

SqlDataAdapter da = new SqlDataAdapter("select * from test",conn);

da.Fill(ds);

TreeNode pNode=null;

AddTree("0", pNode);

}

下面是B/S结构的代码:

DataSet ds = new DataSet();

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

SqlConnection conn = new SqlConnection("server=.;database=test;uid=sa;pwd=;");

SqlDataAdapter da = new SqlDataAdapter("select * from test", conn);

da.Fill(ds);

TreeNode pNode = null;

AddTree("0", pNode);

}

}

public void AddTree(string fatherNum, TreeNode pNode)

{

DataRow[] dr = ds.Tables[0].Select("fatherNum=" + fatherNum);

if (dr.Length > 0)

{

foreach (DataRow d in dr)

{

TreeNode tNode = new TreeNode();

tNode.Text = d["Name"].ToString();

if (pNode == null)

{

//添加根节点

TreeView1.Nodes.Add(tNode);

}

else

{

//添加当前节点的子节点

pNode.ChildNodes.Add(tNode);

tNode.Collapse();

}

AddTree(d["Num"].ToString(), tNode); //递归

}

}

}

=================================================================================

SQL的递归查询

create procedure GetData(@a nvarchar(50))

as

begin

create table #Temp(

a nvarchar(50),

b nvarchar(50),

c nvarchar(50)

)

declare @tempB nvarchar(50)

insert into #Temp select a,b,c from T where a in(@a)

declare cur cursor for select b from #Temp

open cur

fetch next from cur into @tempB

while @@fetch_status = 0

begin

insert into #Temp select a,b,c from T where a in(@tempB)

fetch next from cur into @tempB

end

close cur

deallocate cur

select * from #Temp

end

=====================================================

上面的是假设表结构如下的：

a b c

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