如何使用Dapper从数据库生成模型？

Question

如何使用Dapper从数据库生成模型？

RKh*_*RKh 13 visual-studio-2010 dapper micro-orm

我来自PetaPoco营地.PetaPoco有一个T4模板,可以从数据库中生成模型.Dapper有类似的东西吗？

我使用NuGet安装了Dapper并添加了SqlHelper.cs,但是我没有找到任何从数据库生成模型的东西.

Answer 1

Mat*_*hie 43

我刚刚写了一个SQL查询来为自己完成这项工作.并在需要时使用额外类型更新它.只需将表名称替换为@@@@.

为了制作很多表,我创建了一个临时存储过程来调用.例如. exec createTablePOCO(@tableName)

SELECT 
'public ' + a1.NewType + ' ' + a1.COLUMN_NAME + ' {get;set;}'
,*
 FROM 
(
/*using top because i'm putting an order by ordinal_position on it. 
putting a top on it is the only way for a subquery to be ordered*/
SELECT TOP 100 PERCENT
COLUMN_NAME,
DATA_TYPE,
IS_NULLABLE,
CASE 
    WHEN DATA_TYPE = 'varchar' THEN 'string'
    WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'NO' THEN 'DateTime'
    WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'YES' THEN 'DateTime?'
    WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'YES' THEN 'int?'
    WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'NO' THEN 'int'
    WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'NO' THEN 'Int16'
    WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'YES' THEN 'Int16?'
    WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'NO' THEN 'decimal'
    WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'YES' THEN 'decimal?'
    WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'NO' THEN 'decimal'
    WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'YES' THEN 'decimal?'
    WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'NO' THEN 'decimal'
    WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'YES' THEN 'decimal?'
    WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'NO' THEN 'long'
    WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'YES' THEN 'long?'
    WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'NO' THEN 'byte'
    WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'YES' THEN 'byte?'
    WHEN DATA_TYPE = 'char' THEN 'string'
    WHEN DATA_TYPE = 'timestamp' THEN 'byte[]'
    WHEN DATA_TYPE = 'varbinary' THEN 'byte[]'
    WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'NO' THEN 'bool'
    WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'YES' THEN 'bool?'
    WHEN DATA_TYPE = 'xml' THEN 'string'
END AS NewType
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE TABLE_NAME = '@@@@'
ORDER BY ORDINAL_POSITION
) AS a1

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当DATA_TYPE喜欢'%char%'那么'字符串' (4认同)

Answer 2

Voi*_*Ray 7

Dapper 本身为连接对象提供了很少的扩展方法（查询、执行），并且没有“模型生成器”。也许可以使用其他一些框架来基于数据库模式生成 POCO。

更新：

数据库表到 C# POCO 类 T4 模板

<#@ template language="C#" debug="True" #>

<#@ assembly name="System" #>
<#@ assembly name="System.Data" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="System.Xml" #>

<#@ assembly name="Microsoft.SqlServer.ConnectionInfo" #>
<#@ assembly name="Microsoft.SqlServer.Management.Sdk.Sfc" #>
<#@ assembly name="Microsoft.SqlServer.Smo" #>

<#@ import namespace="System" #>
<#@ import namespace="System.Text" #>
<#@ import namespace="System.Xml" #>
<#@ import namespace="Microsoft.SqlServer.Management.Smo" #>
<#@ import namespace="System.Data.SqlClient" #>
<#@ import namespace="Microsoft.SqlServer.Management.Common" #>

namespace Namespace
{

<#         
   var databaseName = "testDb";
            var serverConnection = new SqlConnection(
                    @"Data Source=.\SQLEXPRESS; Integrated Security=true; Initial Catalog=" + databaseName);
            var svrConnection = new ServerConnection(serverConnection);

   Server srv = new Server(svrConnection);
            foreach (Table table in srv.Databases[databaseName].Tables)
            {

#>
        class <#= table.Name #>
        {
            <#
                foreach (Column col in table.Columns)
                {
                #>
                    public <#= GetNetDataType(col.DataType.Name) #> <#= col.Name #> { get; set; }
                <#
                }
             #>
        }

<#            }
#>
}



<#+
        public static string GetNetDataType(string sqlDataTypeName)
        {

            switch (sqlDataTypeName.ToLower())
            {
                case "bigint":
                    return "Int64";
                case "binary":
                    return "Byte[]";
                case "bit":
                    return "bool";
                case "char":
                    return "char";
                case "cursor":
                    return string.Empty;
                case "datetime":
                    return "DateTime";
                case "decimal":
                    return "Decimal";
                case "float":
                    return "Double";
                case "int":
                    return "int";
                case "money":
                    return "Decimal";
                case "nchar":
                    return "string";
                case "numeric":
                    return "Decimal";
                case "nvarchar":
                    return "string";
                case "real":
                    return "single";
                case "smallint":
                    return "Int16";
                case "text":
                    return "string";
                case "tinyint":
                    return "Byte";
                case "varbinary":
                    return "Byte[]";
                case "xml":
                    return "string";
                case "varchar":
                    return "string";
                case "smalldatetime":
                    return "DateTime";
                case "image":
                    return "byte[]";

                default:
                    return string.Empty;
            }



        }
#>

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我尝试了一下“从所有表生成 POCO”模板，这似乎是一个很好的起点；它执行基本的表到类生成。我在测试时遇到了一些问题，这迫使我对其进行了一些修改；这是更新版本：http://teamyudin.blogspot.com/2012/06/database-tables-to-c-poco-classes-t4.html。 (5认同)

Answer 3

sur*_*gle 7

从游标调用存储过程

如果你结合提到的sp mattritchies(参见上面的答案)并从游标调用它,你可以为数据库中的每个表生成poco类

USE YourDataBaseName
GO 
    DECLARE @field1 nvarchar(400)
    DECLARE cur CURSOR LOCAL for

    SELECT TABLE_NAME FROM information_schema.tables
    OPEN cur
    FETCH NEXT FROM cur INTO @field1 --, @field2
    WHILE @@FETCH_STATUS = 0 BEGIN          
        exec Helper_CreatePocoFromTableName @field1 -- , @field2            
        fetch next from cur into @field1 -- , @field2
    END

close cur
deallocate cur

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存储过程mattritchies提到

我从mattritchies回答(见上文)中获取了sql并创建了他提到的存储过程并对其进行了一些修改,以便它也添加了类名.如果将Management Studio置于文本输出模式并删除列名称的输出,则会获得所有类的复制粘贴文本:

CREATE PROCEDURE [dbo].[Helper_CreatePocoFromTableName]    
    @tableName varchar(100)
AS
BEGIN
SET NOCOUNT ON;

-- Subquery to return only the copy paste text
Select PropertyColumn from (
    SELECT 1 as rowNr, 'public class ' + @tableName + ' {' as PropertyColumn
    UNION
    SELECT 2 as rowNr, 'public ' + a1.NewType + ' ' + a1.COLUMN_NAME + ' {get;set;}' as PropertyColumn
    -- ,* comment added so that i get copy pasteable output
     FROM 
    (
        /*using top because i'm putting an order by ordinal_position on it. 
        putting a top on it is the only way for a subquery to be ordered*/
        SELECT TOP 100 PERCENT
        COLUMN_NAME,
        DATA_TYPE,
        IS_NULLABLE,
        CASE 
            WHEN DATA_TYPE = 'varchar' THEN 'string'
            WHEN DATA_TYPE = 'nvarchar' THEN 'string' 
            WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'NO' THEN 'DateTime'
            WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'YES' THEN 'DateTime?'
            WHEN DATA_TYPE = 'smalldatetime' AND IS_NULLABLE = 'NO' THEN 'DateTime'
            WHEN DATA_TYPE = 'datetime2' AND IS_NULLABLE = 'NO' THEN 'DateTime'
            WHEN DATA_TYPE = 'smalldatetime' AND IS_NULLABLE = 'YES' THEN 'DateTime?'
            WHEN DATA_TYPE = 'datetime2' AND IS_NULLABLE = 'YES' THEN 'DateTime?'
            WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'YES' THEN 'int?'
            WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'NO' THEN 'int'
            WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'NO' THEN 'Int16'
            WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'YES' THEN 'Int16?'
            WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'NO' THEN 'decimal'
            WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'YES' THEN 'decimal?'
            WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'NO' THEN 'decimal'
            WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'YES' THEN 'decimal?'
            WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'NO' THEN 'decimal'
            WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'YES' THEN 'decimal?'
            WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'NO' THEN 'long'
            WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'YES' THEN 'long?'
            WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'NO' THEN 'byte'
            WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'YES' THEN 'byte?'
            WHEN DATA_TYPE = 'char' THEN 'string'                       
            WHEN DATA_TYPE = 'timestamp' THEN 'byte[]'
            WHEN DATA_TYPE = 'varbinary' THEN 'byte[]'
            WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'NO' THEN 'bool'
            WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'YES' THEN 'bool?'
            WHEN DATA_TYPE = 'xml' THEN 'string'
        END AS NewType
        FROM INFORMATION_SCHEMA.COLUMNS 
        WHERE TABLE_NAME = @tableName
        ORDER BY ORDINAL_POSITION
        ) AS a1 
    UNION 
    SELECT 3 as rowNr,  '} // class ' + @tableName
    ) as t Order By rowNr asc
END

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PS:我会把它作为他的答案的编辑建议,但我的经验是,经常编辑建议被拒绝.

更新

用户chris-w-mclean建议我自己没有尝试过以下更改(请参阅他的建议编辑):

替换SELECT 1 as rowNr, 'public class '为SELECT 1.0 as rowNr, 'public class '
替换 SELECT 2 as rowNr, 'public '为SELECT 2 + a1.ORDINAL_POSITION/1000 as rowNr, 'public '
替换 SELECT TOP 100 PERCENT COLUMN_NAME,为SELECT COLUMN_NAME,
在IS_NULLABLE, CASE这一行之间添加cast(ORDINAL_POSITION as float) as ORDINAL_POSITION,
去掉 ORDER BY ORDINAL_POSITION
改变SELECT 3 as以SELECT 3.0 as

Answer 4

Cah*_*hit 6

尝试我稍微优化过的这个版本，这样结果就不需要通过管道传输到文本输出。相反，PRINT 语句允许轻松复制/粘贴输出。我还删除了子查询并添加了 nvarchar/ntext 类型的声明。

这是针对单个表的，但可以将其转换为存储过程以使用上面的游标建议之一。

SET NOCOUNT ON
DECLARE @tbl as varchar(255)
SET @tbl = '@@@@'

DECLARE @flds as varchar(8000)
SET @flds=''

SELECT -1 as f0, 'public class ' + @tbl + ' {' as f1 into #tmp

INSERT #tmp
SELECT 
    ORDINAL_POSITION, 
    '    public ' + 
    CASE 
        WHEN DATA_TYPE = 'varchar' THEN 'string'
        WHEN DATA_TYPE = 'nvarchar' THEN 'string'
        WHEN DATA_TYPE = 'text' THEN 'string'
        WHEN DATA_TYPE = 'ntext' THEN 'string'
        WHEN DATA_TYPE = 'char' THEN 'string'
        WHEN DATA_TYPE = 'xml' THEN 'string'
        WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'NO' THEN 'DateTime'
        WHEN DATA_TYPE = 'datetime' AND IS_NULLABLE = 'YES' THEN 'DateTime?'
        WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'YES' THEN 'int?'
        WHEN DATA_TYPE = 'int' AND IS_NULLABLE = 'NO' THEN 'int'
        WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'NO' THEN 'Int16'
        WHEN DATA_TYPE = 'smallint' AND IS_NULLABLE = 'YES' THEN 'Int16?'
        WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'NO' THEN 'decimal'
        WHEN DATA_TYPE = 'decimal' AND IS_NULLABLE = 'YES' THEN 'decimal?'
        WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'NO' THEN 'decimal'
        WHEN DATA_TYPE = 'numeric' AND IS_NULLABLE = 'YES' THEN 'decimal?'
        WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'NO' THEN 'decimal'
        WHEN DATA_TYPE = 'money' AND IS_NULLABLE = 'YES' THEN 'decimal?'
        WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'NO' THEN 'long'
        WHEN DATA_TYPE = 'bigint' AND IS_NULLABLE = 'YES' THEN 'long?'
        WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'NO' THEN 'byte'
        WHEN DATA_TYPE = 'tinyint' AND IS_NULLABLE = 'YES' THEN 'byte?'
        WHEN DATA_TYPE = 'timestamp' THEN 'byte[]'
        WHEN DATA_TYPE = 'varbinary' THEN 'byte[]'
        WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'NO' THEN 'bool'
        WHEN DATA_TYPE = 'bit' AND IS_NULLABLE = 'YES' THEN 'bool?'
    END + ' ' + COLUMN_NAME + ' {get;set;}'
FROM INFORMATION_SCHEMA.COLUMNS 
        WHERE TABLE_NAME = @tbl

INSERT #tmp SELECT 999, '}'

SELECT @flds=@flds + f1 +'
' from #tmp order by f0

DROP TABLE #tmp

PRINT @flds

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Answer 5

Efr*_*ain 5

我的方法是：

用于<dynamic>获取一些没有类型的行
将这些行序列化为 JSON
从控制台复制 JSON 字符串（或使用调试器）
将其粘贴到 JSON 到 C# 模型生成器中（例如https://app.quicktype.io/）。

IE：

var persons = connection.Query<dynamic>("SELECT * FROM Persons");
var serializedPerson = JsonConvert.Serialize(persons.First());
Console.WriteLine(serializedPerson);

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