dotConnect for Oracle可以使用用戶自定義類型，由于在Oracle數(shù)據(jù)庫(kù)中提供機(jī)制使用類型化和非類型化的oracleobjects。

    非類型化的OracleObjects是由OracleObject類實(shí)例表示。這是一種處理Oracle對(duì)象靈活的機(jī)制，但是卻不能夠類型驗(yàn)證，同時(shí)比起使用類型化OracleObjects.而言，也不是很便捷。

    類型化oracleobject代表單一的用戶定義類型，允許像普通的.NET對(duì)象一樣使用實(shí)例。本文主要是講解如何創(chuàng)建和使用類型化的OracleObjects。值得注意的是，類型化和無(wú)類型化的OracleObjects都可以在OCI模式下使用。

    現(xiàn)在需要用戶定義的類型TAddress，和一張有在你的Oracle 數(shù)據(jù)庫(kù)中創(chuàng)建的TAddress類型字段的表EmpObject，這個(gè)可以通過(guò)下面的代碼實(shí)現(xiàn)：

CREATE TYPE TAddress AS OBJECT (
  Country VARCHAR2(30),
  City VARCHAR2(30),
  Street VARCHAR2(30),
  Apartment NUMBER
);
/

CREATE TABLE EmpObject (
  Code NUMBER PRIMARY KEY,
  Person VARCHAR2(40),
  Address TADDRESS,
  Job VARCHAR2(9)
);
/

INSERT INTO EmpObject (Code, Person, Address, Job)
            VALUES (1, 'SMITH', TAddress('UK', 'London', 'Street', 12), 'CLERK');

INSERT INTO EmpObject (Code, Person, Address, Job)
            VALUES (2, 'JONES', TAddress('USA', 'New York', 'Street', 418), 'MANAGER');

INSERT INTO EmpObject (Code, Person, Address, Job)
            VALUES (3, 'SCOTT', TAddress('CANADA', 'Ottawa', 'Street', 26),'PRESIDENT');

INSERT INTO EmpObject (Code, Person, Address, Job)
            VALUES (4, 'MARTIN', TAddress('FRANCE', 'Paris', 'Street', 162), 'ANALYST');

創(chuàng)建類型化OracleObjects

要?jiǎng)?chuàng)建一個(gè)類型化的OracleObject ，可以執(zhí)行下列步驟：

1、啟動(dòng)類型化Oracle對(duì)象向?qū)В涸趘s的主菜單中選擇Tools -> Oracle -> Oracle Objects。

2、將連接屬性設(shè)置到你創(chuàng)建對(duì)象類型化的服務(wù)器上，然后點(diǎn)擊“下一步”：

注意在OCI模式下使用連接，主要是因?yàn)镺racle對(duì)象在直接模式下不可用。

3、選擇你想要的類型并單擊“下一步”。在此示例中， 使用的是TAddress類型：

4、設(shè)置生成的類的名稱、命名空間的放置、對(duì)象的命名規(guī)則。示例中選擇的是默認(rèn)值。

導(dǎo)航將會(huì)生成用于展示TAddress對(duì)象類型的TAddress類。
使用類型化的OracleObjects

通過(guò)產(chǎn)生的的類型OracleObject類，Oracle UDTs的屬性就可以像通常的.NET對(duì)象一樣使用。下面來(lái)看看如何使用Taddress實(shí)例，代碼如下所示：

C#

// Create and open a connection. Connection should not be in Direct mode,
// as in this case Oracle Objects would be unavailable.
OracleConnection connection = new OracleConnection
	("Server = Ora; User Id = Scott; Password = tiger; Direct = false;");

connection.Open();

// Create a command selecting all rows from the table EmpObject
OracleCommand command = new OracleCommand
	("select * from empobject", connection);

// By default, all Oracle Objects are retrieved by the application as instances 
// of the OracleObject class. Thus, to use typed OracleObjects, we need to set 
// the mapping from the TADDRESS Oracle UDT to Taddress class used in the application.
OracleType.GetObjectType("TAddress", connection).UdtType = typeof(TAddress);

// Execute the command, retrieve the data reader and print the table content.
OracleDataReader r = command.ExecuteReader();
while (r.Read())
{
	TAddress addr = (Taddress)r["Address"];
	Console.WriteLine
		(r["Person"].ToString() + ": " + addr.Country + ", " + 
		addr.City + ", " + addr.Street + " " + addr.Apartment);
}

[Visual Basic]

 Create and open a connection. Connection should not be in Direct mode,
' as in this case Oracle Objects are unavailable.
 Dim connection = New OracleConnection( _
	"Server = Ora; User Id = Scott; Password = tiger; Direct = false;")
connection.Open()

' Create a command selecting all rows from the table EmpObject
Dim command = New OracleCommand
	("select * from empobject", connection)

' By default, all Oracle Objects are retrieved by the application as instances
' of the OracleObject class. Thus, to use typed OracleObjects, we need to set
' the mapping from the TADDRESS Oracle UDT to Taddress class used in the application.
OracleType.GetObjectType("TAddress", connection).UdtType = GetType(TAddress)

' Execute the command, retrieve the data reader and print the table content.
Dim r As OracleDataReader = command.ExecuteReader()
While (r.Read())
	Dim addr As Taddress = r("Address")
	Console.WriteLine( _
		r("Person").ToString() + ": " + addr.Country + ", " + _
		addr.City + ", " + addr.Street + " " + addr.Apartment.ToString())
End While

    下一個(gè)示例是使用Taddress類的參數(shù)更新了EmpObject表，代碼如下所示：

[C#]

// Create an UPDATE command with parameter
OracleCommand command = new OracleCommand
	("update empobject set address = :pAddress where code = 1", connection);
            
// Create and set a Taddress object
Taddress addr = new Taddress();
addr.Country = "USA";
addr.City = "New York";
addr.Street = "Street";
addr.Apartment = 418;

// Set up the command parameter. 
OracleParameter param = new OracleParameter("pAddress", OracleDbType.Object, "TAddress");
param.Value = addr;
command.Parameters.Add(param);

// Execute the command.
command.ExecuteNonQuery();

[Visual Basic]

 Create an UPDATE command with parameter
Dim command = New OracleCommand( _
	"update empobject set address = :pAddress where code = 1", connection)

' Create and set a Taddress object
Dim addr As Taddress = New Taddress()
addr.Country = "USA"
addr.City = "New York"
addr.Street = "Street"
addr.Apartment = 418

' Set up the command parameter. 
Dim param = New OracleParameter("pAddress", OracleDbType.Object, "TAddress")
param.Value = addr
command.Parameters.Add(param)

' Execute the command.
command.ExecuteNonQuery()