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

抓取QueryFirst, visual studio扩展,从SQL查询生成包装类。你不仅得到…

public class MyClass{
    public string MyProp{get;set;}
    public int MyNumberProp{get;set;}
    ...
}

作为奖励,它还会……

public class MyQuery{
    public static IEnumerable<MyClass>Execute(){}
    public static MyClass GetOne(){}
    ...
}

您确定要将类直接基于表吗?表是属于DB的静态规范化数据存储概念。类是动态的、流动的、一次性的、特定于上下文的,也许是非规范化的。为什么不为您想要的操作数据编写真正的查询,然后让QueryFirst从中生成类呢?

其他回答

设置@TableName为你的表名。

declare @TableName sysname = 'TableName'
declare @Result varchar(max) = 'public class ' + @TableName + '
{'

select @Result = @Result + '
    public ' + ColumnType + NullableSign + ' ' + ColumnName + ' { get; set; }
'
from
(
    select 
        replace(col.name, ' ', '_') ColumnName,
        column_id ColumnId,
        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 'double'
            when 'image' then 'byte[]'
            when 'int' then 'int'
            when 'money' then 'decimal'
            when 'nchar' then 'string'
            when 'ntext' then 'string'
            when 'numeric' then 'decimal'
            when 'nvarchar' then 'string'
            when 'real' then 'float'
            when 'smalldatetime' then 'DateTime'
            when 'smallint' then 'short'
            when 'smallmoney' then 'decimal'
            when 'text' then 'string'
            when 'time' then 'TimeSpan'
            when 'timestamp' then 'long'
            when 'tinyint' then 'byte'
            when 'uniqueidentifier' then 'Guid'
            when 'varbinary' then 'byte[]'
            when 'varchar' then 'string'
            else 'UNKNOWN_' + typ.name
        end ColumnType,
        case 
            when col.is_nullable = 1 and typ.name in ('bigint', 'bit', 'date', 'datetime', 'datetime2', 'datetimeoffset', 'decimal', 'float', 'int', 'money', 'numeric', 'real', 'smalldatetime', 'smallint', 'smallmoney', 'time', 'tinyint', 'uniqueidentifier') 
            then '?' 
            else '' 
        end NullableSign
    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
    where object_id = object_id(@TableName)
) t
order by ColumnId

set @Result = @Result  + '
}'

print @Result

要打印NULLABLE属性,请使用此命令。 它对Alex Aza的CASE语句块脚本进行了轻微修改。

declare @TableName sysname = 'TableName'
declare @result varchar(max) = 'public class ' + @TableName + '
{'

select @result = @result + '
    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 AS [ColumnType]
    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 
    where object_id = object_id(@TableName)
) t
order by column_id

set @result = @result  + '
}'

print @result

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  

}

Visual Studio杂志发表了这篇文章:

为SQL查询结果生成。net POCO类

它有一个可下载的项目,你可以构建,给它你的SQL信息,它会为你制作出类。

现在,如果该工具刚刚为SELECT、INSERT和UPDATE创建了SQL命令....

你刚刚做了,只要你的表包含两列,并被称为'tblPeople'之类的东西。

您总是可以编写自己的SQL包装器。实际上我更喜欢这样做,我讨厌生成代码,以任何方式。

也许创建一个DAL类,并有一个名为GetPerson(int id)的方法,用于查询数据库中的person,然后从结果集中创建person对象。