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

为了感谢Alex的解决方案和Guilherme的要求,我为MySQL生成c#类做了这个

set @schema := 'schema_name';
set @table := 'table_name';
SET group_concat_max_len = 2048;
SELECT 
    concat('public class ', @table, '\n{\n', GROUP_CONCAT(a.property_ SEPARATOR '\n'), '\n}') class_
FROM 
    (select
        CONCAT(
        '\tpublic ',
        case 
            when DATA_TYPE = 'bigint' then 'long'
            when DATA_TYPE = 'BINARY' then 'byte[]'
            when DATA_TYPE = 'bit' then 'bool'
            when DATA_TYPE = 'char' then 'string'
            when DATA_TYPE = 'date' then 'DateTime'
            when DATA_TYPE = 'datetime' then 'DateTime'
            when DATA_TYPE = 'datetime2' then 'DateTime'
            when DATA_TYPE = 'datetimeoffset' then 'DateTimeOffset'
            when DATA_TYPE = 'decimal' then 'decimal'
            when DATA_TYPE = 'double' then 'double'
            when DATA_TYPE = 'float' then 'float'
            when DATA_TYPE = 'image' then 'byte[]'
            when DATA_TYPE = 'int' then 'int'
            when DATA_TYPE = 'money' then 'decimal'
            when DATA_TYPE = 'nchar' then 'char'
            when DATA_TYPE = 'ntext' then 'string'
            when DATA_TYPE = 'numeric' then 'decimal'
            when DATA_TYPE = 'nvarchar' then 'string'
            when DATA_TYPE = 'real' then 'double'
            when DATA_TYPE = 'smalldatetime' then 'DateTime'
            when DATA_TYPE = 'smallint' then 'short'
            when DATA_TYPE = 'smallmoney' then 'decimal'
            when DATA_TYPE = 'text' then 'string'
            when DATA_TYPE = 'time' then 'TimeSpan'
            when DATA_TYPE = 'timestamp' then 'DateTime'
            when DATA_TYPE = 'tinyint' then 'byte'
            when DATA_TYPE = 'uniqueidentifier' then 'Guid'
            when DATA_TYPE = 'varbinary' then 'byte[]'
            when DATA_TYPE = 'varchar' then 'string'
            else '_UNKNOWN_'
        end, ' ', 
        COLUMN_NAME, ' {get; set;}') as property_
    FROM INFORMATION_SCHEMA.COLUMNS
    WHERE table_name = @table AND table_schema = @schema) a
;

谢谢Alex和Guilherme!

Oracle DB的另一个解决方案-> c#

单查询 无功能无步骤 Mulitple表

添加DataAnnotations

(例子) (需要) (表) (StringLength) (列) 可以为空

查询

https://gist.github.com/omansak/f19eefffd2d639ac72a1f4b506d8471a

输出

[Table("AGENTS")]
public class Agents
{
    [Key]
    [Required]
    [Column("INT_ID", TypeName = "NUMBER(10,0)", Order = 1)]
    public long IntId { get; set; }
    [Key]
    [Required]
    [StringLength(15)]
    [Column("REFERENCE_CODE", TypeName = "VARCHAR2(15)", Order = 2)]
    public string ReferenceCode { get; set; }
    [Required]
    [Column("PARENT_INT_ID", TypeName = "NUMBER(10,0)", Order = 3)]
    public long ParentIntId { get; set; }
    [Required]
    [StringLength(200)]
    [Column("TITLE", TypeName = "VARCHAR2(200)", Order = 4)]
    public string Title { get; set; }
    [Required]
    [Column("START_DATE", TypeName = "DATE", Order = 5)]
    public DateTime StartDate { get; set; }
    [Required]
    [Column("END_DATE", TypeName = "DATE", Order = 6)]
    public DateTime EndDate { get; set; }
    [Required]
    [StringLength(1)]
    [Column("AGENT_TYPE", TypeName = "VARCHAR2(1)", Order = 7)]
    public string AgentType { get; set; }
    [Required]
    [Column("CREATE_DATE", TypeName = "DATE", Order = 8)]
    public DateTime CreateDate { get; set; }
    [Required]
    [StringLength(32)]
    [Column("CREATE_USER", TypeName = "VARCHAR2(32)", Order = 9)]
    public string CreateUser { get; set; }
    [StringLength(200)]
    [Column("RESPONSIBLE_CONTACT", TypeName = "VARCHAR2(200)", Order = 10)]
    public string ResponsibleContact { get; set; }
    [StringLength(100)]
    [Column("RESPONSIBLE_TITLE", TypeName = "VARCHAR2(100)", Order = 11)]
    public string ResponsibleTitle { get; set; }
    [StringLength(100)]
    [Column("AGENCY_PLATE_NO", TypeName = "VARCHAR2(100)", Order = 12)]
    public string AgencyPlateNo { get; set; }
    [Column("AGENCY_COVER_AMOUNT", TypeName = "NUMBER(24,2)", Order = 13)]
    public double? AgencyCoverAmount { get; set; }
    [StringLength(100)]
    [Column("MERSIS_NO", TypeName = "VARCHAR2(100)", Order = 14)]
    public string MersisNo { get; set; }
    [StringLength(100)]
    [Column("TECH_PERSONEL_NO", TypeName = "VARCHAR2(100)", Order = 15)]
    public string TechPersonelNo { get; set; }
    [StringLength(100)]
    [Column("TECH_PERSONEL_NAME", TypeName = "VARCHAR2(100)", Order = 16)]
    public string TechPersonelName { get; set; }
    [Column("COVER_END_DATE", TypeName = "DATE", Order = 17)]
    public DateTime? CoverEndDate { get; set; }
    [Column("BRANCH_NUMBER", TypeName = "NUMBER(10,0)", Order = 18)]
    public long? BranchNumber { get; set; }
    [Column("ACTION_NUMBER", TypeName = "NUMBER(10,0)", Order = 19)]
    public long? ActionNumber { get; set; }
    [Column("CLUB_PARTICIPATION_COUNT", TypeName = "NUMBER(10,0)", Order = 20)]
    public long? ClubParticipationCount { get; set; }
    [Column("AGENCY_CONTRACT_DATE", TypeName = "DATE", Order = 21)]
    public DateTime? AgencyContractDate { get; set; }
    [StringLength(200)]
    [Column("KEP_ADDRESS", TypeName = "VARCHAR2(200)", Order = 22)]
    public string KepAddress { get; set; }
}

我只是想给感兴趣的人加上我自己的答案。 主要特点有:

It will automatically generate classes for all the tables in the entire schema. Just specify the schema name. It will add System.Data.Linq.Mapping attributes to the class and each property. Useful for anyone using Linq to SQL. declare @TableName sysname declare @Result varchar(max) declare @schema varchar(20) = 'dbo' DECLARE @Cursor CURSOR SET @Cursor = CURSOR FAST_FORWARD FOR SELECT DISTINCT tablename = rc1.TABLE_NAME FROM INFORMATION_SCHEMA.Tables rc1 where rc1.TABLE_SCHEMA = @schema OPEN @Cursor FETCH NEXT FROM @Cursor INTO @TableName WHILE (@@FETCH_STATUS = 0) BEGIN set @Result = '[Table(Name = "' + @schema + '.' + @TableName + '")] public class ' + Replace(@TableName, '$', '_') + ' {' select @Result = @Result + ' [Column' + PriKey +'] public ' + ColumnType + NullableSign + ' ' + ColumnName + ' { get; set; } ' from ( select replace(col.name, ' ', '_') ColumnName, col.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, case when pk.CONSTRAINT_NAME is not null and ic.column_id is not null then '(IsPrimaryKey = true, IsDbGenerated = true)' when pk.CONSTRAINT_NAME is not null then '(IsPrimaryKey = true)' when ic.column_id is not null then '(IsDbGenerated = true)' else '' end PriKey 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 outer join sys.identity_columns ic on ic.column_id = col.column_id and col.object_id = ic.object_id left outer join ( SELECT K.TABLE_NAME , K.COLUMN_NAME , K.CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K ON C.TABLE_NAME = K.TABLE_NAME AND C.CONSTRAINT_CATALOG = K.CONSTRAINT_CATALOG AND C.CONSTRAINT_SCHEMA = K.CONSTRAINT_SCHEMA AND C.CONSTRAINT_NAME = K.CONSTRAINT_NAME where C.CONSTRAINT_TYPE = 'PRIMARY KEY' ) pk on pk.COLUMN_NAME = col.name and pk.TABLE_NAME = @TableName where col.object_id = object_id(@schema + '.' + @TableName) ) t order by ColumnId set @Result = @Result + ' } ' print @Result FETCH NEXT FROM @Cursor INTO @TableName end CLOSE @Cursor DEALLOCATE @Cursor GO

增加了6-29-22:这是为EF Core (dotNet 6.0)生成模型的更新版本。

CREATE FUNCTION [dbo].[InitCap] ( @InputString varchar(4000) ) 
RETURNS VARCHAR(4000)
AS
BEGIN
    DECLARE @Index          INT
    DECLARE @Char           CHAR(1)
    DECLARE @PrevChar       CHAR(1)
    DECLARE @OutputString   VARCHAR(4000)

    SET @OutputString = @InputString
    SET @Index = 1

    WHILE @Index <= LEN(@InputString)
    BEGIN
        SET @Char     = SUBSTRING(@InputString, @Index, 1)
        SET @PrevChar = CASE WHEN @Index = 1 THEN ' '
                             ELSE SUBSTRING(@InputString, @Index - 1, 1)
                        END

        IF @PrevChar IN (' ', ';', ':', '!', '?', ',', '.', '_', '-', '/', '&', '''', '(')
            SET @OutputString = STUFF(@OutputString, @Index, 1, UPPER(@Char))

        SET @Index = @Index + 1
    END

    RETURN @OutputString
END
go


declare @TableName sysname
declare @Result varchar(max)
declare @schema varchar(20) = 'dbo'
DECLARE @Cursor CURSOR

SET @Cursor = CURSOR FAST_FORWARD FOR
SELECT DISTINCT tablename = rc1.TABLE_NAME
FROM INFORMATION_SCHEMA.Tables rc1
where rc1.TABLE_SCHEMA = @schema

OPEN @Cursor FETCH NEXT FROM @Cursor INTO @TableName

WHILE (@@FETCH_STATUS = 0)
BEGIN
set @Result = '[Table("' + @TableName + '", Schema = "' + @schema + '")]
public class ' + Replace(@TableName, '$', '_') + '
{'

select @Result = @Result + '
    [Column("' + ColumnName + '"' + stringType + ')]
    public ' + ColumnType + NullableSign + ' ' + PropertyName + ' { get; set; }
'
from
(
    select 
        replace(col.name, ' ', '_') ColumnName,
        replace(replace([dbo].[InitCap](col.name), ' ', ''), '_', '') PropertyName,
        col.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
            then '?' 
            else '' 
        end NullableSign,
        case
            when typ.name in ('char', 'nchar', 'nvarchar', 'varchar')
            then ', TypeName = "' + typ.name + '(' + convert(varchar, col.max_length) + ')"'
            else ''
        end stringType
    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 outer join sys.identity_columns ic on ic.column_id = col.column_id and col.object_id = ic.object_id
    left outer join (
        SELECT  K.TABLE_NAME ,
            K.COLUMN_NAME ,
            K.CONSTRAINT_NAME
        FROM    INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
                JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K ON C.TABLE_NAME = K.TABLE_NAME
                                                                 AND C.CONSTRAINT_CATALOG = K.CONSTRAINT_CATALOG
                                                                 AND C.CONSTRAINT_SCHEMA = K.CONSTRAINT_SCHEMA
                                                                 AND C.CONSTRAINT_NAME = K.CONSTRAINT_NAME
        where C.CONSTRAINT_TYPE = 'PRIMARY KEY'
    ) pk on pk.COLUMN_NAME = col.name and pk.TABLE_NAME = @TableName
    where col.object_id = object_id(@schema + '.' + @TableName)
) t
order by ColumnId

set @Result = @Result  + '
}

'

print @Result

FETCH NEXT FROM @Cursor INTO @TableName
end

CLOSE @Cursor DEALLOCATE @Cursor
GO

DROP FUNCTION [dbo].[InitCap]
GO

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。

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。