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> $outputFile
}
其他回答
我只是想给感兴趣的人加上我自己的答案。 主要特点有:
It will automatically generate classes for all the tables in the entire schema. Just specify the schema name. It will add System.Data.Linq.Mapping attributes to the class and each property. Useful for anyone using Linq to SQL. declare @TableName sysname declare @Result varchar(max) declare @schema varchar(20) = 'dbo' DECLARE @Cursor CURSOR SET @Cursor = CURSOR FAST_FORWARD FOR SELECT DISTINCT tablename = rc1.TABLE_NAME FROM INFORMATION_SCHEMA.Tables rc1 where rc1.TABLE_SCHEMA = @schema OPEN @Cursor FETCH NEXT FROM @Cursor INTO @TableName WHILE (@@FETCH_STATUS = 0) BEGIN set @Result = '[Table(Name = "' + @schema + '.' + @TableName + '")] public class ' + Replace(@TableName, '$', '_') + ' {' 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
我无法让亚历克斯的答案在Sql Server 2008 R2上工作。所以，我用同样的基本原理重写了它。它现在支持模式，并且对列属性映射(包括将可为空的日期类型映射为可为空的c#值类型)进行了一些修复。下面是Sql语句:
DECLARE @TableName VARCHAR(MAX) = 'NewsItem' -- Replace 'NewsItem' with your table name
DECLARE @TableSchema VARCHAR(MAX) = 'Markets' -- Replace 'Markets' with your schema name
DECLARE @result varchar(max) = ''
SET @result = @result + 'using System;' + CHAR(13) + CHAR(13)
IF (@TableSchema IS NOT NULL)
BEGIN
SET @result = @result + 'namespace ' + @TableSchema + CHAR(13) + '{' + CHAR(13)
END
SET @result = @result + 'public class ' + @TableName + CHAR(13) + '{' + CHAR(13)
SET @result = @result + '#region Instance Properties' + CHAR(13)
SELECT
@result = @result + CHAR(13)
+ ' public ' + ColumnType + ' ' + ColumnName + ' { get; set; } ' + CHAR(13)
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 'bool?'
ELSE 'bool'
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 'int?'
ELSE 'int'
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 'Byte[]'
WHEN 'tinyint' THEN CASE C.IS_NULLABLE
WHEN 'YES' THEN 'Byte?'
ELSE 'Byte'
END
WHEN 'uniqueidentifier' THEN CASE C.IS_NULLABLE
WHEN 'YES' THEN 'Guid?'
ELSE 'Guid'
END
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(@TableSchema, c.TABLE_SCHEMA) = c.TABLE_SCHEMA) t
ORDER BY t.ORDINAL_POSITION
SET @result = @result + CHAR(13) + '#endregion Instance Properties' + CHAR(13)
SET @result = @result + '}' + CHAR(13)
IF (@TableSchema IS NOT NULL)
BEGIN
SET @result = @result + CHAR(13) + '}'
END
PRINT @result
它生成的c#代码如下所示:
using System;
namespace Markets
{
public class NewsItem {
#region Instance Properties
public Int32 NewsItemID { get; set; }
public Int32? TextID { get; set; }
public String Description { get; set; }
#endregion Instance Properties
}
}
It may be an idea to use EF, Linq to Sql, or even Scaffolding; however, there are times when a piece of coding like this comes in handy. Frankly, I do not like using EF navigation properties where the code it generates made 19,200 separate database calls to populate a 1000 row grid. This could have been achieved in a single database call. Nonetheless, it could just be that your technical architect does not want you to use EF and the like. So, you have to revert to code like this... Incidentally, it may also be an idea to decorate each of the properties with attributes for DataAnnotations, etc., but I'm keeping this strictly POCO.
编辑 修正了时间戳和Guid?
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
Visual Studio杂志发表了这篇文章:
为SQL查询结果生成。net POCO类
它有一个可下载的项目，你可以构建，给它你的SQL信息，它会为你制作出类。
现在，如果该工具刚刚为SELECT、INSERT和UPDATE创建了SQL命令....
要打印带有注释(摘要)的NULLABLE属性，使用这个。 这是对第一个答案的轻微修改
declare @TableName sysname = 'TableName'
declare @result varchar(max) = 'public class ' + @TableName + '
{'
select @result = @result
+ CASE WHEN ColumnDesc IS NOT NULL THEN '
/// <summary>
/// ' + ColumnDesc + '
/// </summary>' ELSE '' END
+ '
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 ColumnType,
colDesc.colDesc AS ColumnDesc
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
OUTER APPLY (
SELECT TOP 1 CAST(value AS NVARCHAR(max)) AS colDesc
FROM
sys.extended_properties
WHERE
major_id = col.object_id
AND
minor_id = COLUMNPROPERTY(major_id, col.name, 'ColumnId')
) colDesc
where object_id = object_id(@TableName)
) t
order by column_id
set @result = @result + '
}'
print @result
