如何从SQL Server表对象生成类?

我说的不是使用ORM。我只需要创建实体(简单类)。喜欢的东西:

    public class Person 
    {
        public string Name { get;set; }
        public string Phone { get;set; }
    }

给定一个表,比如:

+----+-------+----------------+
| ID | Name  |     Phone      |
+----+-------+----------------+
|  1 | Alice | (555) 555-5550 |
|  2 | Bob   | (555) 555-5551 |
|  3 | Cathy | (555) 555-5552 |
+----+-------+----------------+



当前回答

使用模板创建自定义代码

create PROCEDURE [dbo].[createCode]
(   
   @TableName sysname = '',
   @befor varchar(max)='public class  @TableName  
{',
   @templet varchar(max)=' 
     public @ColumnType @ColumnName   { get; set; }  // @ColumnDesc  ',
   @after varchar(max)='
}'

)
AS
BEGIN 


declare @result varchar(max)

set @befor =replace(@befor,'@TableName',@TableName)

set @result=@befor

select @result = @result 
+ replace(replace(replace(replace(replace(@templet,'@ColumnType',ColumnType) ,'@ColumnName',ColumnName) ,'@ColumnDesc',ColumnDesc),'@ISPK',ISPK),'@max_length',max_length)

from  
(
    select 
    column_id,
    replace(col.name, ' ', '_') ColumnName,
    typ.name as sqltype,
    typ.max_length,
    is_identity,
    pkk.ISPK, 
        case typ.name 
            when 'bigint' then 'long'
            when 'binary' then 'byte[]'
            when 'bit' then 'bool'
            when 'char' then 'String'
            when 'date' then 'DateTime'
            when 'datetime' then 'DateTime'
            when 'datetime2' then 'DateTime'
            when 'datetimeoffset' then 'DateTimeOffset'
            when 'decimal' then 'decimal'
            when 'float' then 'float'
            when 'image' then 'byte[]'
            when 'int' then 'int'
            when 'money' then 'decimal'
            when 'nchar' then 'char'
            when 'ntext' then 'string'
            when 'numeric' then 'decimal'
            when 'nvarchar' then 'String'
            when 'real' then 'double'
            when 'smalldatetime' then 'DateTime'
            when 'smallint' then 'short'
            when 'smallmoney' then 'decimal'
            when 'text' then 'String'
            when 'time' then 'TimeSpan'
            when 'timestamp' then 'DateTime'
            when 'tinyint' then 'byte'
            when 'uniqueidentifier' then 'Guid'
            when 'varbinary' then 'byte[]'
            when 'varchar' then 'string'
            else 'UNKNOWN_' + typ.name
        END + CASE WHEN col.is_nullable=1 AND typ.name NOT IN ('binary', 'varbinary', 'image', 'text', 'ntext', 'varchar', 'nvarchar', 'char', 'nchar') THEN '?' ELSE '' END ColumnType,
      isnull(colDesc.colDesc,'') AS ColumnDesc 
    from sys.columns col
        join sys.types typ on
            col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
            left join
            (
                SELECT c.name  AS 'ColumnName', CASE WHEN dd.pk IS NULL THEN 'false' ELSE 'true' END ISPK           
                FROM        sys.columns c
                    JOIN    sys.tables  t   ON c.object_id = t.object_id    
                    LEFT JOIN (SELECT   K.COLUMN_NAME , C.CONSTRAINT_TYPE as pk  
                        FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K 
                            LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
                        ON K.TABLE_NAME = C.TABLE_NAME
                            AND K.CONSTRAINT_NAME = C.CONSTRAINT_NAME
                            AND K.CONSTRAINT_CATALOG = C.CONSTRAINT_CATALOG
                            AND K.CONSTRAINT_SCHEMA = C.CONSTRAINT_SCHEMA            
                        WHERE K.TABLE_NAME = @TableName) as dd
                     ON dd.COLUMN_NAME = c.name
                 WHERE       t.name = @TableName       
            ) pkk  on ColumnName=col.name

    OUTER APPLY (
    SELECT TOP 1 CAST(value AS NVARCHAR(max)) AS colDesc
    FROM
       sys.extended_properties
    WHERE
       major_id = col.object_id
       AND
       minor_id = COLUMNPROPERTY(major_id, col.name, 'ColumnId')
    ) colDesc      
    where object_id = object_id(@TableName)

    ) t

    set @result=@result+@after

    select @result
    --print @result

END

现在创建自定义代码

例如c#类

exec [createCode] @TableName='book',@templet =' 
     public @ColumnType @ColumnName   { get; set; }  // @ColumnDesc  '

输出是

public class  book  
{ 
     public long ID   { get; set; }  //    
     public String Title   { get; set; }  // Book Title  
}

对LINQ

exec [createCode] @TableName='book'
, @befor  ='[System.Data.Linq.Mapping.Table(Name = "@TableName")]
public class @TableName
{',

   @templet  =' 
     [System.Data.Linq.Mapping.Column(Name = "@ColumnName", IsPrimaryKey = @ISPK)]
     public @ColumnType @ColumnName   { get; set; }  // @ColumnDesc  
     ' ,

   @after  ='
}'

输出是

[System.Data.Linq.Mapping.Table(Name = "book")]
public class book
{ 
     [System.Data.Linq.Mapping.Column(Name = "ID", IsPrimaryKey = true)]
     public long ID   { get; set; }  //   

     [System.Data.Linq.Mapping.Column(Name = "Title", IsPrimaryKey = false)]
     public String Title   { get; set; }  // Book Title  

}

Java类

exec [createCode] @TableName='book',@templet =' 
     public @ColumnType @ColumnName ; // @ColumnDesc  
     public @ColumnType get@ColumnName()
     {
        return this.@ColumnName;
     }
     public void set@ColumnName(@ColumnType @ColumnName)
     {
        this.@ColumnName=@ColumnName;
     }

     '

输出是

public class  book  
{ 
     public long ID ; //   
     public long getID()
     {
        return this.ID;
     }
     public void setID(long ID)
     {
        this.ID=ID;
     }


     public String Title ; // Book Title  
     public String getTitle()
     {
        return this.Title;
     }
     public void setTitle(String Title)
     {
        this.Title=Title;
     } 
}

为android sugarOrm模型

exec [createCode] @TableName='book'
, @befor  ='@Table(name = "@TableName")
public class @TableName
{',
   @templet  =' 
     @Column(name = "@ColumnName")
     public @ColumnType @ColumnName ;// @ColumnDesc  
     ' ,
   @after  ='
}'

输出是

@Table(name = "book")
public class book
{ 
     @Column(name = "ID")
     public long ID ;//   

     @Column(name = "Title")
     public String Title ;// Book Title  

}

其他回答

我很困惑你想要从这里得到什么,但这里是在设计你想要设计的东西时的一般选择。

在Visual Studio版本中使用内置的ORM。 自己编写一个,类似于您的代码示例。通常情况下,如果你不确定怎么做,教程是你最好的朋友。 使用另一种ORM,如NHibernate。

商业化,但codessmith Generator做到了:http://www.codesmithtools.com/product/generator

我将几个基于SQL的答案(主要是Alex Aza的根答案)打包到kassify中,这是一个控制台应用程序,可以一次性为指定的数据库生成所有类:


例如,给定一个Users表,它是这样的:

+----+------------------+-----------+---------------------+
| Id |       Name       | Username  |        Email        |
+----+------------------+-----------+---------------------+
|  1 | Leanne Graham    | Bret      | Sincere@april.biz   |
|  2 | Ervin Howell     | Antonette | Shanna@melissa.tv   |
|  3 | Clementine Bauch | Samantha  | Nathan@yesenia.net  |
+----+------------------+-----------+---------------------+

klassify将生成一个名为Users.cs的文件,看起来像这样:

    public class User 
    {
        public int Id {get; set; }
        public string Name { get;set; }
        public string Username { get; set; }
        public string Email { get; set; }
    }

它将为每个表输出一个文件。丢弃你不用的东西。

使用

 --out, -o:
        output directory     << defaults to the current directory >>
 --user, -u:
        sql server user id   << required >>
 --password, -p:
        sql server password  << required >>
 --server, -s:
        sql server           << defaults to localhost >>
 --database, -d:
        sql database         << required >>
 --timeout, -t:
        connection timeout   << defaults to 30 >>
 --help, -h:
        show help

Postgres DB -> c#的另一个解决方案

兼容NpgSQL 添加DataAnnotations

    SELECT
            CASE 
                WHEN c.is_nullable ='NO'  THEN '[Required]'||chr(10)
                ELSE '' END
            ||CASE 
                WHEN c.data_type = 'character varying' THEN format('[StringLength(%s)]',c.character_maximum_length)||chr(10)
                ELSE '' END
            ||'public '
            ||CASE 
                WHEN c.data_type = 'integer' THEN 'int'
                WHEN c.data_type = 'boolean' THEN 'bool'
                WHEN c.data_type = 'double precision' THEN 'double'
                WHEN c.data_type = 'uuid' THEN 'Guid'
                WHEN c.data_type = 'character varying' THEN 'string'
                WHEN c.data_type = 'timestamp without time zone' THEN 'DateTime'    
                WHEN c.data_type = 'bigint' THEN 'long'   
                WHEN c.data_type = 'bytea' THEN 'byte[]'    
            ELSE 'object' END
            ||CASE
                WHEN c.is_nullable='YES' AND NOT  c.data_type = 'character varying' THEN '? '
                ELSE ' ' END
            ||c.column_name||' {get;set;}'
            ,c.*
    FROM information_schema."columns" c
    WHERE 1=1
    AND c.table_name='YOUR_TABLE_NAME'


要打印带有注释(摘要)的NULLABLE属性,使用这个。 这是对第一个答案的轻微修改

declare @TableName sysname = 'TableName'
declare @result varchar(max) = 'public class ' + @TableName + '
{'
select @result = @result 
+ CASE WHEN ColumnDesc IS NOT NULL THEN '
    /// <summary>
    /// ' + ColumnDesc + '
    /// </summary>' ELSE '' END
+ '
    public ' + ColumnType + ' ' + ColumnName + ' { get; set; }'
from
(
    select 
        replace(col.name, ' ', '_') ColumnName,
        column_id,
        case typ.name 
            when 'bigint' then 'long'
            when 'binary' then 'byte[]'
            when 'bit' then 'bool'
            when 'char' then 'String'
            when 'date' then 'DateTime'
            when 'datetime' then 'DateTime'
            when 'datetime2' then 'DateTime'
            when 'datetimeoffset' then 'DateTimeOffset'
            when 'decimal' then 'decimal'
            when 'float' then 'float'
            when 'image' then 'byte[]'
            when 'int' then 'int'
            when 'money' then 'decimal'
            when 'nchar' then 'char'
            when 'ntext' then 'string'
            when 'numeric' then 'decimal'
            when 'nvarchar' then 'String'
            when 'real' then 'double'
            when 'smalldatetime' then 'DateTime'
            when 'smallint' then 'short'
            when 'smallmoney' then 'decimal'
            when 'text' then 'String'
            when 'time' then 'TimeSpan'
            when 'timestamp' then 'DateTime'
            when 'tinyint' then 'byte'
            when 'uniqueidentifier' then 'Guid'
            when 'varbinary' then 'byte[]'
            when 'varchar' then 'string'
            else 'UNKNOWN_' + typ.name
        END + CASE WHEN col.is_nullable=1 AND typ.name NOT IN ('binary', 'varbinary', 'image', 'text', 'ntext', 'varchar', 'nvarchar', 'char', 'nchar') THEN '?' ELSE '' END ColumnType,
        colDesc.colDesc AS ColumnDesc
    from sys.columns col
        join sys.types typ on
            col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
    OUTER APPLY (
    SELECT TOP 1 CAST(value AS NVARCHAR(max)) AS colDesc
    FROM
       sys.extended_properties
    WHERE
       major_id = col.object_id
       AND
       minor_id = COLUMNPROPERTY(major_id, col.name, 'ColumnId')
    ) colDesc            
    where object_id = object_id(@TableName)
) t
order by column_id

set @result = @result  + '
}'

print @result