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
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....
其他回答
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。
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"
Java类生成
declare @TableName varchar(max) = 'Restaurants'
declare @Templete varchar(max) = '
public @ColumnType @ColumnName ; // @ColumnDesc
public @ColumnType get@ColumnName()
{
return this.@ColumnName;
}
public void set@ColumnName(@ColumnType @ColumnName)
{
this.@ColumnName=@ColumnName;
}
'
declare @before varchar(max)='public class @TableName
{'
declare @after varchar(max)='
}'
declare @result varchar(max)
set @before =replace(@before,'@TableName',@TableName)
set @result=@before
select @result = @result
+ replace(replace(replace(replace(replace(@Templete,'@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
VB版
declare @TableName sysname = 'myTableName'
declare @prop varchar(max)
PRINT 'Public Class ' + @TableName
declare props cursor for
select distinct ' public property ' + ColumnName + ' AS ' + ColumnType AS prop
from (
select
replace(col.name, ' ', '_') ColumnName, column_id,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'boolean'
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 'integer'
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'
end ColumnType
from sys.columns col join sys.types typ on col.system_type_id = typ.system_type_id
where object_id = object_id(@TableName)
) t
order by prop
open props
FETCH NEXT FROM props INTO @prop
WHILE @@FETCH_STATUS = 0
BEGIN
print @prop
FETCH NEXT FROM props INTO @prop
END
close props
DEALLOCATE props
PRINT 'End Class'
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
}
