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

从Postgres DB生成

DO $$ DECLARE v_tabela varchar; DECLARE v_cursor_colunas record; DECLARE v_nome_coluna varchar; DECLARE v_classe VARCHAR; DECLARE v_tipo VARCHAR; DECLARE v_schema_name VARCHAR; BEGIN v_schema_name := 'my-schema'; v_tabela := 'my-table'; select table_name INTO v_tabela from information_schema.tables where table_schema = v_schema_name and table_type = 'BASE TABLE' and table_name = v_tabela; v_classe := E'\r\n' || 'public class ' || v_tabela || ' {' || E'\r\n'; FOR v_cursor_colunas IN SELECT column_name as coluna, is_nullable as isnull, data_type as tipo, character_maximum_length as tamanho FROM information_schema.columns WHERE table_schema = v_schema_name AND table_name = v_tabela LOOP IF v_cursor_colunas.tipo='character varying' THEN v_tipo:= 'string'; ELSIF v_cursor_colunas.tipo='character' and v_cursor_colunas.tamanho=1 THEN v_tipo:= 'char'; ELSIF v_cursor_colunas.tipo='character' and v_cursor_colunas.tamanho<>1 THEN v_tipo:= 'string'; ELSIF v_cursor_colunas.tipo like 'timestamp%' THEN v_tipo:= 'DateTime'; IF v_cursor_colunas.isnull='YES' then v_tipo:= 'DateTime?'; END IF; ELSIF v_cursor_colunas.tipo='boolean' THEN v_tipo:= 'bool'; IF v_cursor_colunas.isnull='YES' then v_tipo:= 'bool?'; END IF; ELSIF v_cursor_colunas.tipo='integer' THEN v_tipo:= 'int'; IF v_cursor_colunas.isnull='YES' then v_tipo:= 'int?'; END IF; ELSIF v_cursor_colunas.tipo='numeric' THEN v_tipo:= 'double'; IF v_cursor_colunas.isnull='YES' then v_tipo:= 'double?'; END IF; ELSIF v_cursor_colunas.tipo='text' THEN v_tipo:= 'string'; ELSE v_tipo:= 'another'; END IF; v_nome_coluna := v_cursor_colunas.coluna; v_classe := v_classe || 'public ' || v_tipo || ' ' || v_cursor_colunas.coluna || ' { get; set; }' || E'\r\n'; END LOOP;

v_class:= v_class || E'\r\n' || '}'; RAISE NOTICE '%', v_class; $ $;

其他回答

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

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'


是的,这些是伟大的,如果你使用一个简单的ORM像Dapper。

如果你使用。net,你可以在运行时使用WriteXmlSchema方法用任何数据集生成XSD文件。http://msdn.microsoft.com/en-us/library/xt7k72x8 (v = vs.110) . aspx

是这样的:

using (SqlConnection cnn = new SqlConnection(mConnStr)) {
DataSet Data = new DataSet();
cnn.Open();
string sql = "SELECT * FROM Person";

using (SqlDataAdapter Da = new SqlDataAdapter(sql, cnn))
{
try
{
    Da.Fill(Data);
    Da.TableMappings.Add("Table", "Person");
    Data.WriteXmlSchema(@"C:\Person.xsd");
}
catch (Exception ex)
{ MessageBox.Show(ex.Message); }
}
cnn.Close();

从那里,您可以使用xsd.exe创建一个可从开发人员命令提示符序列化XML的类。 http://msdn.microsoft.com/en-us/library/x6c1kb0s (v = vs.110) . aspx

是这样的:

xsd C:\Person.xsd /classes /language:CS

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。

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。