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
VB版
declare @TableName sysname = 'myTableName'
declare @prop varchar(max)
PRINT 'Public Class ' + @TableName
declare props cursor for
select distinct ' public property ' + ColumnName + ' AS ' + ColumnType AS prop
from (
select
replace(col.name, ' ', '_') ColumnName, column_id,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'boolean'
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 'integer'
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'
end ColumnType
from sys.columns col join sys.types typ on col.system_type_id = typ.system_type_id
where object_id = object_id(@TableName)
) t
order by prop
open props
FETCH NEXT FROM props INTO @prop
WHILE @@FETCH_STATUS = 0
BEGIN
print @prop
FETCH NEXT FROM props INTO @prop
END
close props
DEALLOCATE props
PRINT 'End Class'
其他回答
VB版
declare @TableName sysname = 'myTableName'
declare @prop varchar(max)
PRINT 'Public Class ' + @TableName
declare props cursor for
select distinct ' public property ' + ColumnName + ' AS ' + ColumnType AS prop
from (
select
replace(col.name, ' ', '_') ColumnName, column_id,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'boolean'
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 'integer'
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'
end ColumnType
from sys.columns col join sys.types typ on col.system_type_id = typ.system_type_id
where object_id = object_id(@TableName)
) t
order by prop
open props
FETCH NEXT FROM props INTO @prop
WHILE @@FETCH_STATUS = 0
BEGIN
print @prop
FETCH NEXT FROM props INTO @prop
END
close props
DEALLOCATE props
PRINT 'End Class'
如果你可以访问SQL Server 2016，你可以使用FOR JSON(包含INCLUDE_NULL_VALUES)选项从选择语句中获取JSON输出。复制输出，然后在Visual Studio中，粘贴special ->，粘贴JSON作为类。
算是预算上的解决方案，但可能会节省一些时间。
我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
}
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
因为之前没有人提到它，所以还有Scaffold-DbContext
在NuGet Package Manager控制台类型如下: Microsoft.EntityFrameworkCore.SqlServer -OutputDir "输出目录"
