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
因为之前没有人提到它，所以还有Scaffold-DbContext
在NuGet Package Manager控制台类型如下: Microsoft.EntityFrameworkCore.SqlServer -OutputDir "输出目录"
其他回答
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'
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
}
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
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。
如果你可以访问SQL Server 2016，你可以使用FOR JSON(包含INCLUDE_NULL_VALUES)选项从选择语句中获取JSON输出。复制输出，然后在Visual Studio中，粘贴special ->，粘贴JSON作为类。
算是预算上的解决方案，但可能会节省一些时间。
