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
我喜欢用私有本地成员和公共访问器/突变器来设置我的类。 因此，我修改了上面的Alex脚本，以便为任何感兴趣的人做到这一点。
declare @TableName sysname = 'TABLE_NAME'
declare @result varchar(max) = 'public class ' + @TableName + '
{'
SET @result = @result +
'
public ' + @TableName + '()
{}
';
select @result = @result + '
private ' + ColumnType + ' ' + ' m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ';'
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 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 + '
'
select @result = @result + '
public ' + ColumnType + ' ' + ColumnName + ' { get { return m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ';} set {m_' + stuff(replace(ColumnName, '_', ''), 1, 1, lower(left(ColumnName, 1))) + ' = value;} }' 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 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
其他回答
Postgres DB -> c#的另一个解决方案
兼容NpgSQL 添加DataAnnotations
SELECT
CASE
WHEN c.is_nullable ='NO' THEN '[Required]'||chr(10)
ELSE '' END
||CASE
WHEN c.data_type = 'character varying' THEN format('[StringLength(%s)]',c.character_maximum_length)||chr(10)
ELSE '' END
||'public '
||CASE
WHEN c.data_type = 'integer' THEN 'int'
WHEN c.data_type = 'boolean' THEN 'bool'
WHEN c.data_type = 'double precision' THEN 'double'
WHEN c.data_type = 'uuid' THEN 'Guid'
WHEN c.data_type = 'character varying' THEN 'string'
WHEN c.data_type = 'timestamp without time zone' THEN 'DateTime'
WHEN c.data_type = 'bigint' THEN 'long'
WHEN c.data_type = 'bytea' THEN 'byte[]'
ELSE 'object' END
||CASE
WHEN c.is_nullable='YES' AND NOT c.data_type = 'character varying' THEN '? '
ELSE ' ' END
||c.column_name||' {get;set;}'
,c.*
FROM information_schema."columns" c
WHERE 1=1
AND c.table_name='YOUR_TABLE_NAME'
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。
从顶部回复略有修改:
declare @TableName sysname = 'HistoricCommand'
declare @Result varchar(max) = '[System.Data.Linq.Mapping.Table(Name = "' + @TableName + '")]
public class Dbo' + @TableName + '
{'
select @Result = @Result + '
[System.Data.Linq.Mapping.Column(Name = "' + t.ColumnName + '", IsPrimaryKey = ' + pkk.ISPK + ')]
public ' + ColumnType + NullableSign + ' ' + t.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 'string'
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,
(
SELECT c.name AS 'ColumnName', CASE WHEN dd.pk IS NULL THEN 'false' ELSE 'true' END ISPK
FROM sys.columns c
JOIN sys.tables t ON c.object_id = t.object_id
LEFT JOIN (SELECT K.COLUMN_NAME , C.CONSTRAINT_TYPE as pk
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K
LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
ON K.TABLE_NAME = C.TABLE_NAME
AND K.CONSTRAINT_NAME = C.CONSTRAINT_NAME
AND K.CONSTRAINT_CATALOG = C.CONSTRAINT_CATALOG
AND K.CONSTRAINT_SCHEMA = C.CONSTRAINT_SCHEMA
WHERE K.TABLE_NAME = @TableName) as dd
ON dd.COLUMN_NAME = c.name
WHERE t.name = @TableName
) pkk
where pkk.ColumnName = t.ColumnName
order by ColumnId
set @Result = @Result + '
}'
print @Result
这使得输出需要完整的LINQ在c#声明
[System.Data.Linq.Mapping.Table(Name = "HistoricCommand")]
public class DboHistoricCommand
{
[System.Data.Linq.Mapping.Column(Name = "HistoricCommandId", IsPrimaryKey = true)]
public int HistoricCommandId { get; set; }
[System.Data.Linq.Mapping.Column(Name = "PHCloudSoftwareInstanceId", IsPrimaryKey = true)]
public int PHCloudSoftwareInstanceId { get; set; }
[System.Data.Linq.Mapping.Column(Name = "CommandType", IsPrimaryKey = false)]
public int CommandType { get; set; }
[System.Data.Linq.Mapping.Column(Name = "InitiatedDateTime", IsPrimaryKey = false)]
public DateTime InitiatedDateTime { get; set; }
[System.Data.Linq.Mapping.Column(Name = "CompletedDateTime", IsPrimaryKey = false)]
public DateTime CompletedDateTime { get; set; }
[System.Data.Linq.Mapping.Column(Name = "WasSuccessful", IsPrimaryKey = false)]
public bool WasSuccessful { get; set; }
[System.Data.Linq.Mapping.Column(Name = "Message", IsPrimaryKey = false)]
public string Message { get; set; }
[System.Data.Linq.Mapping.Column(Name = "ResponseData", IsPrimaryKey = false)]
public string ResponseData { get; set; }
[System.Data.Linq.Mapping.Column(Name = "Message_orig", IsPrimaryKey = false)]
public string Message_orig { get; set; }
[System.Data.Linq.Mapping.Column(Name = "Message_XX", IsPrimaryKey = false)]
public string Message_XX { get; set; }
}
我只是想表达我的意见
0) QueryFirst https://marketplace.visualstudio.com/items?itemName=bbsimonbb.QueryFirst Query-first is a visual studio extension for working intelligently with SQL in C# projects. Use the provided .sql template to develop your queries. When you save the file, Query-first runs your query, retrieves the schema and generates two classes and an interface: a wrapper class with methods Execute(), ExecuteScalar(), ExecuteNonQuery() etc, its corresponding interface, and a POCO encapsulating a line of results.
1) Sql2Objects 从查询结果开始创建类(但不是DAL)
2) https://learn.microsoft.com/en-us/ef/ef6/resources/tools
3) https://visualstudiomagazine.com/articles/2012/12/11/sqlqueryresults-code-generation.aspx
4) http://www.codesmithtools.com/product/generator#features
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
}
