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

我尝试使用上面的建议,并在这个过程中改进了这个线程中的解决方案。

让我们假设您使用实现PropertyChanged事件的基类(在本例中为ObservableObject),您将像这样做。有一天我可能会在我的博客上写一篇博客文章 sqljana.wordpress.com

请将前三个变量的值替换为:

    --These three things have to be substituted (when called from Powershell, they are replaced before execution)
DECLARE @Schema VARCHAR(MAX) = N'&Schema'
DECLARE @TableName VARCHAR(MAX) = N'&TableName'
DECLARE @Namespace VARCHAR(MAX) = N'&Namespace'

DECLARE @CRLF VARCHAR(2) = CHAR(13) + CHAR(10);
DECLARE @result VARCHAR(max) = ' '

DECLARE @PrivateProp VARCHAR(100) = @CRLF + 
                CHAR(9) + CHAR(9) + 'private <ColumnType> _<ColumnName>;';
DECLARE @PublicProp VARCHAR(255) = @CRLF + 
                CHAR(9) + CHAR(9) + 'public <ColumnType> <ColumnName> '  + @CRLF +
                CHAR(9) + CHAR(9) + '{ ' + @CRLF +
                CHAR(9) + CHAR(9) + '   get { return _<ColumnName>; } ' + @CRLF +
                CHAR(9) + CHAR(9) + '   set ' + @CRLF +
                CHAR(9) + CHAR(9) + '   { ' + @CRLF +
                CHAR(9) + CHAR(9) + '       _<ColumnName> = value;' + @CRLF +
                CHAR(9) + CHAR(9) + '       base.RaisePropertyChanged();' + @CRLF +
                CHAR(9) + CHAR(9) + '   } ' + @CRLF +
                CHAR(9) + CHAR(9) + '}' + @CRLF;

DECLARE @RPCProc VARCHAR(MAX) = @CRLF +         
                CHAR(9) + CHAR(9) + 'public event PropertyChangedEventHandler PropertyChanged; ' + @CRLF +
                CHAR(9) + CHAR(9) + 'private void RaisePropertyChanged( ' + @CRLF +
                CHAR(9) + CHAR(9) + '       [CallerMemberName] string caller = "" ) ' + @CRLF +
                CHAR(9) + CHAR(9) + '{  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   if (PropertyChanged != null)  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   { ' + @CRLF +
                CHAR(9) + CHAR(9) + '       PropertyChanged( this, new PropertyChangedEventArgs( caller ) );  ' + @CRLF +
                CHAR(9) + CHAR(9) + '   } ' + @CRLF +
                CHAR(9) + CHAR(9) + '}';

DECLARE @PropChanged VARCHAR(200) =  @CRLF +            
                CHAR(9) + CHAR(9) + 'protected override void AfterPropertyChanged(string propertyName) ' + @CRLF +
                CHAR(9) + CHAR(9) + '{ ' + @CRLF +
                CHAR(9) + CHAR(9) + '   System.Diagnostics.Debug.WriteLine("' + @TableName + ' property changed: " + propertyName); ' + @CRLF +
                CHAR(9) + CHAR(9) + '}';

SET @result = 'using System;' + @CRLF + @CRLF +
                'using MyCompany.Business;' + @CRLF + @CRLF +
                'namespace ' + @Namespace  + @CRLF + '{' + @CRLF +
                '   public class ' + @TableName + ' : ObservableObject' + @CRLF + 
                '   {' + @CRLF +
                '   #region Instance Properties' + @CRLF 

SELECT @result = @result
                 + 
                REPLACE(
                            REPLACE(@PrivateProp
                            , '<ColumnName>', ColumnName)
                        , '<ColumnType>', ColumnType)
                +                           
                REPLACE(
                            REPLACE(@PublicProp
                            , '<ColumnName>', ColumnName)
                        , '<ColumnType>', ColumnType)                   
FROM
(
    SELECT  c.COLUMN_NAME   AS ColumnName 
        , CASE c.DATA_TYPE   
            WHEN 'bigint' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int64?' ELSE 'Int64' END
            WHEN 'binary' THEN 'Byte[]'
            WHEN 'bit' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Boolean?' ELSE 'Boolean' END            
            WHEN 'char' THEN 'String'
            WHEN 'date' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetime' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetime2' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                        
            WHEN 'datetimeoffset' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTimeOffset?' ELSE 'DateTimeOffset' END                                    
            WHEN 'decimal' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                    
            WHEN 'float' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Single?' ELSE 'Single' END                                    
            WHEN 'image' THEN 'Byte[]'
            WHEN 'int' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int32?' ELSE 'Int32' END
            WHEN 'money' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                
            WHEN 'nchar' THEN 'String'
            WHEN 'ntext' THEN 'String'
            WHEN 'numeric' THEN
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                            
            WHEN 'nvarchar' THEN 'String'
            WHEN 'real' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Double?' ELSE 'Double' END                                                                        
            WHEN 'smalldatetime' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                                    
            WHEN 'smallint' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Int16?' ELSE 'Int16'END            
            WHEN 'smallmoney' THEN  
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Decimal?' ELSE 'Decimal' END                                                                        
            WHEN 'text' THEN 'String'
            WHEN 'time' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'TimeSpan?' ELSE 'TimeSpan' END                                                                                    
            WHEN 'timestamp' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'DateTime?' ELSE 'DateTime' END                                    
            WHEN 'tinyint' THEN 
                CASE C.IS_NULLABLE
                    WHEN 'YES' THEN 'Byte?' ELSE 'Byte' END                                                
            WHEN 'uniqueidentifier' THEN 'Guid'
            WHEN 'varbinary' THEN 'Byte[]'
            WHEN 'varchar' THEN 'String'
            ELSE 'Object'
        END AS ColumnType
        , c.ORDINAL_POSITION 
FROM    INFORMATION_SCHEMA.COLUMNS c
WHERE   c.TABLE_NAME = @TableName 
    AND ISNULL(@Schema, c.TABLE_SCHEMA) = c.TABLE_SCHEMA  
) t
ORDER BY t.ORDINAL_POSITION

SELECT @result = @result + @CRLF + 
                CHAR(9) + '#endregion Instance Properties' + @CRLF +
                --CHAR(9) + @RPCProc + @CRLF +
                CHAR(9) + @PropChanged + @CRLF +
                CHAR(9) + '}' + @CRLF +
                @CRLF + '}' 
--SELECT @result
PRINT @result

基类基于Josh Smith的文章 从http://joshsmithonwpf.wordpress.com/2007/08/29/a-base-class-which-implements-inotifypropertychanged/

我确实将类重命名为ObservableObject,并使用CallerMemberName属性利用了c# 5的一个特性

//From http://joshsmithonwpf.wordpress.com/2007/08/29/a-base-class-which-implements-inotifypropertychanged/
//
//Jana's change: Used c# 5 feature to bypass passing in the property name using [CallerMemberName] 
//  protected void RaisePropertyChanged([CallerMemberName] string propertyName = "")

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.CompilerServices;

namespace MyCompany.Business
{

    /// <summary>
    /// Implements the INotifyPropertyChanged interface and 
    /// exposes a RaisePropertyChanged method for derived 
    /// classes to raise the PropertyChange event.  The event 
    /// arguments created by this class are cached to prevent 
    /// managed heap fragmentation.
    /// </summary>
    [Serializable]
    public abstract class ObservableObject : INotifyPropertyChanged
    {
        #region Data

        private static readonly Dictionary<string, PropertyChangedEventArgs> eventArgCache;
        private const string ERROR_MSG = "{0} is not a public property of {1}";

        #endregion // Data

        #region Constructors

        static ObservableObject()
        {
            eventArgCache = new Dictionary<string, PropertyChangedEventArgs>();
        }

        protected ObservableObject()
        {
        }

        #endregion // Constructors

        #region Public Members

        /// <summary>
        /// Raised when a public property of this object is set.
        /// </summary>
        [field: NonSerialized]
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        /// Returns an instance of PropertyChangedEventArgs for 
        /// the specified property name.
        /// </summary>
        /// <param name="propertyName">
        /// The name of the property to create event args for.
        /// </param>        
        public static PropertyChangedEventArgs
            GetPropertyChangedEventArgs(string propertyName)
        {
            if (String.IsNullOrEmpty(propertyName))
                throw new ArgumentException(
                    "propertyName cannot be null or empty.");

            PropertyChangedEventArgs args;

            // Get the event args from the cache, creating them
            // and adding to the cache if necessary.
            lock (typeof(ObservableObject))
            {
                bool isCached = eventArgCache.ContainsKey(propertyName);
                if (!isCached)
                {
                    eventArgCache.Add(
                        propertyName,
                        new PropertyChangedEventArgs(propertyName));
                }

                args = eventArgCache[propertyName];
            }

            return args;
        }

        #endregion // Public Members

        #region Protected Members

        /// <summary>
        /// Derived classes can override this method to
        /// execute logic after a property is set. The 
        /// base implementation does nothing.
        /// </summary>
        /// <param name="propertyName">
        /// The property which was changed.
        /// </param>
        protected virtual void AfterPropertyChanged(string propertyName)
        {
        }

        /// <summary>
        /// Attempts to raise the PropertyChanged event, and 
        /// invokes the virtual AfterPropertyChanged method, 
        /// regardless of whether the event was raised or not.
        /// </summary>
        /// <param name="propertyName">
        /// The property which was changed.
        /// </param>
        protected void RaisePropertyChanged([CallerMemberName] string propertyName = "")
        {
            this.VerifyProperty(propertyName);

            PropertyChangedEventHandler handler = this.PropertyChanged;
            if (handler != null)
            {
                // Get the cached event args.
                PropertyChangedEventArgs args =
                    GetPropertyChangedEventArgs(propertyName);

                // Raise the PropertyChanged event.
                handler(this, args);
            }

            this.AfterPropertyChanged(propertyName);
        }

        #endregion // Protected Members

        #region Private Helpers

        [Conditional("DEBUG")]
        private void VerifyProperty(string propertyName)
        {
            Type type = this.GetType();

            // Look for a public property with the specified name.
            PropertyInfo propInfo = type.GetProperty(propertyName);

            if (propInfo == null)
            {
                // The property could not be found,
                // so alert the developer of the problem.

                string msg = string.Format(
                    ERROR_MSG,
                    propertyName,
                    type.FullName);

                Debug.Fail(msg);
            }
        }

        #endregion // Private Helpers
    }
}

下面是你们会更喜欢的部分。我构建了一个Powershell脚本来为SQL数据库中的所有表生成。它是基于一个名为Chad Miller的Powershell大师的Invoke-SQLCmd2 cmdlet,可以从这里下载: http://gallery.technet.microsoft.com/ScriptCenter/7985b7ef-ed89-4dfd-b02a-433cc4e30894/

一旦有了cmdlet,为所有表生成的Powershell脚本就变得简单了(一定要用特定的值替换变量)。

. C:\MyScripts\Invoke-Sqlcmd2.ps1

$serverInstance = "MySQLInstance"
$databaseName = "MyDb"
$generatorSQLFile = "C:\MyScripts\ModelGen.sql" 
$tableListSQL = "SELECT name FROM $databaseName.sys.tables"
$outputFolder = "C:\MyScripts\Output\"
$namespace = "MyCompany.Business"

$placeHolderSchema = "&Schema"
$placeHolderTableName = "&TableName"
$placeHolderNamespace = "&Namespace"

#Get the list of tables in the database to generate c# models for
$tables = Invoke-Sqlcmd2 -ServerInstance $serverInstance -Database $databaseName -Query $tableListSQL -As DataRow -Verbose

foreach ($table in $tables)
{
    $table1 = $table[0]
    $outputFile = "$outputFolder\$table1.cs"


    #Replace variables with values (returns an array that we convert to a string to use as query)
    $generatorSQLFileWSubstitutions = (Get-Content $generatorSQLFile).
                                            Replace($placeHolderSchema,"dbo").
                                            Replace($placeHolderTableName, $table1).
                                            Replace($placeHolderNamespace, $namespace) | Out-String

    "Ouputing for $table1 to $outputFile"

    #The command generates .cs file content for model using "PRINT" statements which then gets written to verbose output (stream 4)
    # ...capture the verbose output and redirect to a file
    (Invoke-Sqlcmd2 -ServerInstance $serverInstance -Database $databaseName -Query $generatorSQLFileWSubstitutions -Verbose) 4> $outputFile

}

其他回答

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

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; $ $;

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。

这篇文章救了我好几次。我只是想补充我的意见。 对于那些不喜欢使用orm,而是编写自己的DAL类的人来说,当你在一个表中有20个列,40个不同的表有各自的CRUD操作时,这是痛苦和浪费时间的。我重复了上面的代码,用于基于表实体和属性生成CRUD方法。

 declare @TableName sysname = 'Tablename'
declare @Result varchar(max) = 'public class ' + @TableName + '
{'

select @Result = @Result + '
    public ' + ColumnType + NullableSign + ' ' + 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 '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,
        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
order by ColumnId

set @Result = @Result  + '
}'

print @Result

declare @InitDataAccess varchar(max) = 'public class '+ @TableName +'DataAccess 
{ '

declare @ListStatement varchar(max) ='public List<'+@TableName+'> Get'+@TableName+'List()
{
 String conn = ConfigurationManager.ConnectionStrings["ConnectionNameInWeb.config"].ConnectionString;
 var itemList = new List<'+@TableName+'>();
          try
            {
                using (var sqlCon = new SqlConnection(conn))
                {
                    sqlCon.Open();
                    var cmd = new SqlCommand
                    {
                        Connection = sqlCon,
                        CommandType = CommandType.StoredProcedure,
                        CommandText = "StoredProcedureSelectAll"
                    };
                    SqlDataReader reader = cmd.ExecuteReader();
                    while (reader.Read())
                    {
                      var item = new '+@TableName+'();
' 
select @ListStatement = @ListStatement + '
item.'+ ColumnName + '= ('+ ColumnType + NullableSign  +')reader["'+ColumnName+'"];
'
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 '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,
        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
order by ColumnId

select @ListStatement = @ListStatement +'
                        itemList.Add(item);
                    }

                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
            return itemList;
        }'

declare @GetIndividual varchar(max) =  
'public '+@TableName+' Get'+@TableName+'()
{
 String conn = ConfigurationManager.ConnectionStrings["ConnectionNameInWeb.config"].ConnectionString;
 var item = new '+@TableName+'();
          try
            {
                using (var sqlCon = new SqlConnection(conn))
                {
                    sqlCon.Open();
                    var cmd = new SqlCommand
                    {
                        Connection = sqlCon,
                        CommandType = CommandType.StoredProcedure,
                        CommandText = "StoredProcedureSelectIndividual"
                    };
                     cmd.Parameters.AddWithValue("@ItemCriteria", item.id);
                    SqlDataReader reader = cmd.ExecuteReader();
                    if (reader.Read())
                    {' 
select @GetIndividual = @GetIndividual + '
item.'+ ColumnName + '= ('+ ColumnType + NullableSign  +')reader["'+ColumnName+'"];
'
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 '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,
        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
order by ColumnId

select @GetIndividual = @GetIndividual +'

                    }

                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
            return item;
        }'



declare @InsertStatement varchar(max) = 'public void  Insert'+@TableName+'('+@TableName+' item)
{
 String conn = ConfigurationManager.ConnectionStrings["ConnectionNameInWeb.config"].ConnectionString;

          try
            {
                using (var sqlCon = new SqlConnection(conn))
                {
                    sqlCon.Open();
                    var cmd = new SqlCommand
                    {
                        Connection = sqlCon,
                        CommandType = CommandType.StoredProcedure,
                        CommandText = "StoredProcedureInsert"
                    };

                    ' 
select @InsertStatement = @InsertStatement + '
 cmd.Parameters.AddWithValue("@'+ColumnName+'", item.'+ColumnName+');
'
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 '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,
        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
order by ColumnId

select @InsertStatement = @InsertStatement +'

                    cmd.ExecuteNonQuery();

                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }

        }'

declare @UpdateStatement varchar(max) = 'public void  Update'+@TableName+'('+@TableName+' item)
{
 String conn = ConfigurationManager.ConnectionStrings["ConnectionNameInWeb.config"].ConnectionString;

          try
            {
                using (var sqlCon = new SqlConnection(conn))
                {
                    sqlCon.Open();
                    var cmd = new SqlCommand
                    {
                        Connection = sqlCon,
                        CommandType = CommandType.StoredProcedure,
                        CommandText = "StoredProcedureUpdate"
                    };
                    cmd.Parameters.AddWithValue("@UpdateCriteria", item.Id);
                    ' 
select @UpdateStatement = @UpdateStatement + '
 cmd.Parameters.AddWithValue("@'+ColumnName+'", item.'+ColumnName+');
'
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 '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,
        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
order by ColumnId

select @UpdateStatement = @UpdateStatement +'

                    cmd.ExecuteNonQuery();

                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }

        }'

declare @EndDataAccess varchar(max)  = '
}'
 print @InitDataAccess
 print @GetIndividual
print @InsertStatement
print @UpdateStatement
print @ListStatement
print @EndDataAccess

当然它不是防弹代码,并且可以改进。只是想为这个优秀的解决方案做点贡献

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?