Add several Entity Framework functions (record memo)

Public static class databaseextensions
{
Public static datatable sqlqueryfordatatatable (this database dB, string SQL, Params sqlparameter [] parameters)
{

Sqlconnection conn = new system. Data. sqlclient. sqlconnection ();
Conn. connectionstring = dB. Connection. connectionstring;
If (conn. State! = Connectionstate. open)
{
Conn. open ();
}
Sqlcommand cmd = new sqlcommand ();
Cmd. Connection = conn;
Cmd. commandtext = SQL;

If (parameters. length> 0)
{
Foreach (VAR item in parameters)
{
Cmd. Parameters. Add (item );
}
}

Sqldataadapter adapter = new sqldataadapter (CMD );
Datatable table = new datatable ();
Adapter. Fill (table );
Return table;
}

Public static ienumerable sqlqueryfordynamic (this database dB, string SQL, Params object [] parameters)
{
Idbconnection defaultconn = new system. Data. sqlclient. sqlconnection ();
Return sqlqueryfordynamicotherdb (dB, SQL, defaultconn, parameters );
}

Public static ienumerable sqlqueryfordynamicotherdb (this database dB, string SQL, idbconnection Conn, Params object [] parameters)
{
Conn. connectionstring = dB. Connection. connectionstring;
If (conn. State! = Connectionstate. open)
{
Conn. open ();
}

Idbcommand cmd = conn. createcommand ();
Cmd. commandtext = SQL;

Idatareader datareader = cmd. executereader ();

If (! Datareader. Read ())
{
Return NULL; // null is returned If no result is returned.
}

# Region build dynamic fields

Typebuilder builder = databaseextensions. createtypebuilder (
"Ef_dynamicmodelassembly ",
"Dynamicmodule ",
"Dynamictype ");

Int fieldcount = datareader. fieldcount;
For (INT I = 0; I <fieldcount; I ++)
{
// DIC. Add (I, datareader. getname (I ));

// Type = datareader. getfieldtype (I );

Databaseextensions. createautoimplementedproperty (
Builder,
Datareader. getname (I ),
Datareader. getfieldtype (I ));
}

# Endregion

Datareader. Close ();
Datareader. Dispose ();
Cmd. Dispose ();
Conn. Close ();
Conn. Dispose ();

Type returntype = builder. createtype ();

If (parameters! = NULL)
{
Return dB. sqlquery (returntype, SQL, parameters );
}
Else
{
Return dB. sqlquery (returntype, SQL );
}
}

Public static typebuilder createtypebuilder (string assemblyname, string modulename, string typename)
{
Typebuilder = appdomain. currentdomain. definedynamicassembly (
New assemblyname (assemblyname ),
Assemblybuilderaccess. Run). definedynamicmodule (modulename). definetype (typename,
Typeattributes. Public );
Typebuilder. definedefaultconstructor (methodattributes. Public );
Return typebuilder;
}

Public static void createautoimplementedproperty (typebuilder builder, string propertyname, type propertytype)
{
Const string privatefieldprefix = "M _";
Const string getterprefix = "GET _";
Const string setterprefix = "SET _";

// Generate the field.
Fieldbuilder = builder. definefield (
String. Concat (
Privatefieldprefix, propertyname ),
Propertytype,
Fieldattributes. Private );

// Generate the property
Propertybuilder = builder. defineproperty (
Propertyname,
System. reflection. propertyattributes. hasdefault,
Propertytype, null );

// Property getter and setter attributes.
Methodattributes propertymethodattributes = methodattributes. Public
| Methodattributes. specialname
| Methodattributes. hidebysig;

// Define the getter method.
Methodbuilder gettermethod = builder. definemethod (
String. Concat (
Getterprefix, propertyname ),
Propertymethodattributes,
Propertytype,
Type. emptytypes );

// Emit the Il code.
// Ldarg.0
// Ld1_, _ Field
// RET
Ilgenerator getterilcode = gettermethod. getilgenerator ();
Getterilcode. emit (Opcodes. ldarg_0 );
Getterilcode. emit (Opcodes. lddes, fieldbuilder );
Getterilcode. emit (Opcodes. Ret );

// Define the setter method.
Methodbuilder settermethod = builder. definemethod (
String. Concat (setterprefix, propertyname ),
Propertymethodattributes,
Null,
New Type [] {propertytype });

// Emit the Il code.
// Ldarg.0
// Ldarg.1
// Stfld, _ Field
// RET
Ilgenerator setterilcode = settermethod. getilgenerator ();
Setterilcode. emit (Opcodes. ldarg_0 );
Setterilcode. emit (Opcodes. ldarg_1 );
Setterilcode. emit (Opcodes. stdes, fieldbuilder );
Setterilcode. emit (Opcodes. Ret );

Propertybuilder. setgetmethod (gettermethod );
Propertybuilder. setsetmethod (settermethod );
}

}