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

View Code

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

    }
}

View Code

　　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

    }
}

View Code

如上可以生成所有表的基本实体类