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
我将几个基于SQL的答案(主要是Alex Aza的根答案)打包到kassify中，这是一个控制台应用程序，可以一次性为指定的数据库生成所有类:
例如，给定一个Users表，它是这样的:
+----+------------------+-----------+---------------------+
| Id | Name | Username | Email |
+----+------------------+-----------+---------------------+
| 1 | Leanne Graham | Bret | Sincere@april.biz |
| 2 | Ervin Howell | Antonette | Shanna@melissa.tv |
| 3 | Clementine Bauch | Samantha | Nathan@yesenia.net |
+----+------------------+-----------+---------------------+
klassify将生成一个名为Users.cs的文件，看起来像这样:
public class User
{
public int Id {get; set; }
public string Name { get;set; }
public string Username { get; set; }
public string Email { get; set; }
}
它将为每个表输出一个文件。丢弃你不用的东西。
使用
--out, -o:
output directory << defaults to the current directory >>
--user, -u:
sql server user id << required >>
--password, -p:
sql server password << required >>
--server, -s:
sql server << defaults to localhost >>
--database, -d:
sql database << required >>
--timeout, -t:
connection timeout << defaults to 30 >>
--help, -h:
show help
其他回答
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....
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
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; $ $;
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
}
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。
