从数据库表生成类

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

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'

2021-06-14 20:12:07

其他回答

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?

2016-05-31 15:58:03

从顶部回复略有修改:

declare @TableName sysname = 'HistoricCommand'

declare @Result varchar(max) = '[System.Data.Linq.Mapping.Table(Name = "' + @TableName + '")]
public class Dbo' + @TableName + '
{'

select @Result = @Result + '
    [System.Data.Linq.Mapping.Column(Name = "' + t.ColumnName + '", IsPrimaryKey = ' + pkk.ISPK + ')]
    public ' + ColumnType + NullableSign + ' ' + t.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 'float'
            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 '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 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, 
(
                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
where pkk.ColumnName = t.ColumnName
order by ColumnId

set @Result = @Result  + '
}'

print @Result

这使得输出需要完整的LINQ在c#声明

[System.Data.Linq.Mapping.Table(Name = "HistoricCommand")]
public class DboHistoricCommand
{
    [System.Data.Linq.Mapping.Column(Name = "HistoricCommandId", IsPrimaryKey = true)]
    public int HistoricCommandId { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "PHCloudSoftwareInstanceId", IsPrimaryKey = true)]
    public int PHCloudSoftwareInstanceId { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "CommandType", IsPrimaryKey = false)]
    public int CommandType { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "InitiatedDateTime", IsPrimaryKey = false)]
    public DateTime InitiatedDateTime { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "CompletedDateTime", IsPrimaryKey = false)]
    public DateTime CompletedDateTime { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "WasSuccessful", IsPrimaryKey = false)]
    public bool WasSuccessful { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "Message", IsPrimaryKey = false)]
    public string Message { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "ResponseData", IsPrimaryKey = false)]
    public string ResponseData { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "Message_orig", IsPrimaryKey = false)]
    public string Message_orig { get; set; }

    [System.Data.Linq.Mapping.Column(Name = "Message_XX", IsPrimaryKey = false)]
    public string Message_XX { get; set; }

}

2017-04-11 23:27:49

我喜欢用私有本地成员和公共访问器/突变器来设置我的类。因此，我修改了上面的Alex脚本，以便为任何感兴趣的人做到这一点。

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

SET @result = @result + 
'
    public ' + @TableName + '()
    {}
';

select @result = @result + '
    private ' + ColumnType + ' ' + ' m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ';'
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 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 + '
'

select @result = @result + '
    public ' + ColumnType + ' ' + ColumnName + ' { get { return m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ';} set {m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ' = value;} }' 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 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

2014-07-17 20:08:22

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

2013-10-01 18:14:22

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。

2016-08-16 16:59:43

从数据库表生成类

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