做自己的代码生成器

代码生成器 顾名思义：自动生成代码，这儿我们主要指 生成数据库表的对应实体类代码。

1 要生成具体表的实体类代码 我们首先需要知道 这个表有哪些字段 每个字段的类型

　　通过下面的sql 语句 就可以得到 ‘youtablename’ 表的列名 类型 长度 等相关信息 循环便利的dataset 就可以得到 实体类的属性字段

SELECT colorder=C.column_id,ColumnName=C.name,TypeName=T.name,
 Length=C.max_length, Preci=C.precision, Scale=C.scale,
 IsIdentity=CASE WHEN C.is_identity=1 THEN N'1'ELSE N'' END,
isPK=ISNULL(IDX.PrimaryKey,N''),
Computed=CASE WHEN C.is_computed=1 THEN N'1'ELSE N'' END,
 IndexName=ISNULL(IDX.IndexName,N''), IndexSort=ISNULL(IDX.Sort,N''),
 Create_Date=O.Create_Date, Modify_Date=O.Modify_date,
 cisNull=CASE WHEN C.is_nullable=1 THEN N'1'ELSE N'' END,
 defaultVal=ISNULL(D.definition,N''),
 deText=ISNULL(PFD.[value],N'')
 FROM sys.columns C INNER JOIN sys.objects O 
ON C.[object_id]=O.[object_id] AND O.type='U' AND O.is_ms_shipped=0 INNER JOIN sys.types T 
ON C.user_type_id=T.user_type_id LEFT JOIN sys.default_constraints D 
ON C.[object_id]=D.parent_object_id 
AND C.column_id=D.parent_column_id 
AND C.default_object_id=D.[object_id] 
LEFT JOIN sys.extended_properties PFD ON PFD.class=1 
AND C.[object_id]=PFD.major_id AND C.column_id=PFD.minor_id 
LEFT JOIN sys.extended_properties PTB ON PTB.class=1 AND PTB.minor_id=0 
AND C.[object_id]=PTB.major_id LEFT JOIN 
( SELECT IDXC.[object_id], IDXC.column_id, Sort=CASE 
INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending') 
WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END, PrimaryKey=CASE WHEN IDX.is_primary_key=1 
THEN N'1'ELSE N'' END, IndexName=IDX.Name FROM sys.indexes IDX INNER JOIN sys.index_columns IDXC 
ON IDX.[object_id]=IDXC.[object_id] AND IDX.index_id=IDXC.index_id LEFT JOIN sys.key_constraints KC 
ON IDX.[object_id]=KC.[parent_object_id] AND IDX.index_id=KC.unique_index_id INNER JOIN 
( SELECT [object_id], Column_id, index_id=MIN(index_id) FROM sys.index_columns 
GROUP BY [object_id], Column_id ) IDXCUQ 
ON IDXC.[object_id]=IDXCUQ.[object_id] AND 
IDXC.Column_id=IDXCUQ.Column_id AND IDXC.index_id=IDXCUQ.index_id ) IDX 
ON C.[object_id]=IDX.[object_id] AND C.column_id=IDX.column_id 
WHERE O.name=N'youtablename' ORDER BY O.name,C.column_id

2 为了使生成的代码更方便 我们可以建立类似模版 来辅助生成代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace &namespace&
{
    public class &classname&
    {
        #region Property

            &property&

        #endregion

        #region Functions

            &functions&

        #endregion

    }
}

　　如上代码提供一个简单的代码模版

　　生成之后的代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TestInsert
{
    public class GoodsTable
    {
        #region Property

        public string GoodsId { get; set; }

        public string GoodsName { get; set; }

        public decimal GoodsPrice { get; set; }

        public Int16 GoodsInventory { get; set; }

        #endregion

        #region Functions

        public void Insert(string goodsid, string goodsname, decimal goodsprice, Int16 goodsinventory)
        { 
            
        }
            
        #endregion

    }
}

如上可以生成所有表的基本实体类