需要从递归生成视图 table

Question

如果有人能提供帮助，我就卡在这一点上了：我有 table 看起来像下面

请注意：可以有 n 个级别，但是如果您在级别中添加项目，则不能创建子级别。

从上面我想生成这种视图：

即使在 c# 中可行，也请指出。我该怎么做？

Answer 1

它应该很简单：

CREATE VIEW YourViewName
AS
    WITH Tree (ID, [NAME], PARENT_ID, Depth, Sort) AS
    (
        SELECT ID, [NAME], PARENT_ID, 0 AS Depth, CONVERT(varchar(255), [Name]) AS Sort         
        FROM Category
        WHERE PARENT_ID = 0
        UNION ALL
        SELECT CT.ID, CT.[NAME], CT.PARENT_ID, Parent.Depth + 1 AS Depth, 
        CONVERT(varchar(255), Parent.Sort + ' | ' + CT.[NAME]) AS Sort
        FROM Category CT
        INNER JOIN Tree as Parent ON Parent.ID = CT.PARENT_ID
    )

    -- HERE IS YOUR TREE, Depths gives you the level starting with 0 and Sort is the Name based path
    SELECT ID, [NAME], PARENT_ID, Depth, Sort FROM Tree
GO

Answer 2

我喜欢递归程序

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public static DataTable inputTable = new DataTable();
        public static DataTable outputTable = new DataTable();
        public static List<List<KeyValuePair<string,string>>> parseRows = new List<List<KeyValuePair<string,string>>>();
        public Form1()
        {
            InitializeComponent();

            inputTable.Columns.Add("Index", typeof(string));
            inputTable.Columns.Add("Title", typeof(string));

            inputTable.Rows.Add(new string[] { "01", "EQUITY" });
            inputTable.Rows.Add(new string[] { "01-001", "MR. J" });
            inputTable.Rows.Add(new string[] { "01-002", "MR. K" });
            inputTable.Rows.Add(new string[] { "01-003", "MR. L" });
            inputTable.Rows.Add(new string[] { "01-004", "MR. M" });
            inputTable.Rows.Add(new string[] { "02", "TRADE CREDITORS" });
            inputTable.Rows.Add(new string[] { "02-001", "TRADE CREDITORS RAW MATERIALS" });
            inputTable.Rows.Add(new string[] { "02-001-0001", "TRADE CREDITORS ITEM X" });
            inputTable.Rows.Add(new string[] { "02-001-0001-001", "MR. A" });
            inputTable.Rows.Add(new string[] { "02-001-0001-002", "MR. B" });
            inputTable.Rows.Add(new string[] { "02-001-0001-003", "MR. C" });
            inputTable.Rows.Add(new string[] { "02-001-0001-004", "MR. D" });
            inputTable.Rows.Add(new string[] { "02-002", "TRADE CREDITORS PACKING MATERIALS" });
            inputTable.Rows.Add(new string[] { "02-002-0001", "MR. X" });
            inputTable.Rows.Add(new string[] { "02-002-0002", "MR. Y" });
            inputTable.Rows.Add(new string[] { "02-002-0003", "MR. Z" });

            RecursiveParseTable("", new List<KeyValuePair<string,string>>());

            //get maximum number of columns for table
            int maxColumns = parseRows.Select(x => x.Count()).Max();

            //create output table
            for (int i = 0; i < maxColumns; i++)
            {
                outputTable.Columns.Add("Index " + (i + 1).ToString(), typeof(string));
                outputTable.Columns.Add("Title " + (i + 1).ToString(), typeof(string));
            }
            foreach(List<KeyValuePair<string, string>> row in parseRows)
            {
                DataRow newRow = outputTable.Rows.Add();
                int colIndex = 0;
                foreach (KeyValuePair<string, string> col in row)
                {
                    newRow[colIndex] = col.Key;
                    newRow[colIndex + 1] = col.Value;
                    colIndex += 2;
                }

            }
            dataGridView1.DataSource = outputTable;
        }
        public static void RecursiveParseTable(string index, List<KeyValuePair<string, string>> titles)
        {
            List<DataRow> children = null;
            if (index.Length == 0)
            {
                children = inputTable.AsEnumerable().Where(x => !x.Field<string>("Index").Contains("-")).ToList();
            }
            else
            {
                int startParseIndex = index.Length + 1;  //only get child indexes with no dash so you don't get grandchildren
                children = inputTable.AsEnumerable().Where(x => 
                    (x.Field<string>("Index").StartsWith(index + "-")) && 
                    (!x.Field<string>("Index").Substring(startParseIndex).Contains("-"))
                    ).ToList();
            }
            children = children.OrderBy(x => x.Field<string>("Index")).ToList();

            if (children.Count == 0)
            {

                parseRows.Add(titles);
            }
            else
            {
                foreach (DataRow child in children)
                {
                    List<KeyValuePair<string, string>> childTitles = new List<KeyValuePair<string, string>>();
                    childTitles.AddRange(titles);

                    string childIndex = child.Field<string>("Index");
                    string childTitle = child.Field<string>("Title");

                    childTitles.Add(new KeyValuePair<string, string>(childIndex, childTitle));
                    RecursiveParseTable(childIndex, childTitles);
                }

            }

        }

    }


}

需要从递归生成视图 table

Need to generate a view from recursive table

c#

sql

recursive-query