• 其他 分部分项 生成 FullPath


    生成后的样子

    代码

    
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Data.SqlClient;
    using System.Linq;
    using System.Reflection;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace ConsoleApp1
    {
        public class Class12
        {
    
    
            /*
             
             后面还需要执行的SQL语句
             
            测试SQL语句
            select REPLACE('泸州长江六桥', '长江', '') 
            select REPLACE(FullPath, '泸州长江六桥', '') from Projects
            select REPLACE(FullPath, '/泸州长江六桥/', '') from Projects where Id>510321
    
            主要是这两句
            update Projects set  FullPath=REPLACE(FullPath, '/泸州长江六桥/', '') where Id>510321
            update Projects set FullPath=REPLACE(FullPath, '/', '') where Id=510321
             
             */
    
    
    
            public void createFullPath()
            {
                var dt = ExecuteDataTable($"select * from Projects order by Id asc", null);
                var list = DataTableToEntities<Projects>(dt);
                var dic = list.ToDictionary(c => c.Id, c => c);
    
                for (int i = 0; i < list.Count; i++)
                {
                    var item = list[i];
                    if (item.ParentId == 0)
                    {
                        item.FullPath = "/" + item.ProjectName;
                    }
                    else
                    {
                        var item2 = dic[item.ParentId.Value];
                        item.FullPath = item2.FullPath + "/" + item.ProjectName;
                    }
                    Console.WriteLine(item.FullPath);
                }
    
    
                int num = 0;
                StringBuilder sb = new StringBuilder();
                list.ForEach(c =>
                {
                    num++;
                    Console.WriteLine("num:" + num);
                    sb.Append($"update Projects set FullPath='{c.FullPath}' where Id='{c.Id}';");
                    if (num % 2000 == 0)
                    {
                        ExecuteScalar(sb.ToString());
                        sb.Clear();
                    }
                });
    
                ExecuteScalar(sb.ToString());
                sb.Clear();
            }
    
    
    
    
    
            public static string conStr = "data source=192.168.2.51; initial catalog=LZCJLQBimDb;user id=sa;password=Sql123456; ";
    
    
            private int ExecuteScalar(string sql)
            {
                if (!sql.EndsWith(";"))
                {
                    sql += ";";
                }
                int n = -1;
                using (SqlConnection con = new SqlConnection(conStr))
                {
                    using (SqlCommand cmd = new SqlCommand(sql, con))
                    {
                        con.Open();
                        n = Convert.ToInt32(cmd.ExecuteScalar());
                    }
                }
                return n;
            }
    
    
    
    
            // 返回DataTable
            public static DataTable ExecuteDataTable(string sql, params SqlParameter[] param)
            {
                DataTable dt = new DataTable();
                using (SqlConnection con = new SqlConnection(conStr))
                {
                    using (SqlDataAdapter adapter = new SqlDataAdapter(sql, con))
                    {
                        //添加参数
                        if (param != null)
                        {
                            adapter.SelectCommand.Parameters.AddRange(param);
                        }
                        adapter.Fill(dt);
                    }
                }
                return dt;
            }
    
    
    
            // DataTable转换为Entitys
            public static List<T> DataTableToEntities<T>(DataTable dt) where T : class, new()
            {
                if (null == dt || dt.Rows.Count == 0) { return null; }
                List<T> entities = new List<T>();
                List<string> columnNames = new List<string>();
    
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    columnNames.Add(dt.Columns[i].ColumnName);
                }
    
                foreach (DataRow row in dt.Rows)
                {
                    PropertyInfo[] pArray = typeof(T).GetProperties();
                    T entity = new T();
    
                    Array.ForEach<PropertyInfo>(pArray, p =>
                    {
                        if (!columnNames.Contains(p.Name))
                        {
                            return;
                        }
    
                        object cellvalue = row[p.Name];
    
                        //空值不处理
                        if (cellvalue == DBNull.Value)
                        {
                            return;
                        }
                        if ((cellvalue == null) || string.IsNullOrWhiteSpace(cellvalue.ToString().Trim()))
                        {
                            return;
                        }
    
                        if (cellvalue != DBNull.Value)
                        {
                            //经过了几个版本的迭代,最后一个为最新的,摘自网上,已附原文地址
    
                            //4、原地址:https://blog.csdn.net/Simon1003/article/details/80839744
                            if (!p.PropertyType.IsGenericType)
                            {
                                p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null);
                            }
                            else
                            {
                                Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition();
                                if (genericTypeDefinition == typeof(Nullable<>))
                                {
                                    p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null);
                                }
                                else
                                {
                                    throw new Exception("genericTypeDefinition != typeof(Nullable<>)");
                                }
                            }
                        }
                    });
                    entities.Add(entity);
                }
                return entities;
            }
    
    
            public class Projects
            {
                public int Id { get; set; }
                public int? ParentId { get; set; }
                public string ProjectName { get; set; }
                public string ProjectCode { get; set; }
    
    
                public string FullPath { get; set; }
            }
    
        }
    }
    
    
    
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  • 原文地址:https://www.cnblogs.com/guxingy/p/15429366.html
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