userdefinedtype.vb

SQL Server 业已成为最为流行的几大数据库之一

Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server

<Serializable()> _
<Microsoft.SqlServer.Server.SqlUserDefinedType(Format.UserDefined, MaxByteSize:=512)> _
Public Structure UserDefinedType
    Implements INullable, IBinarySerialize

   

    Private TypeId As Integer
    Private TypeName As String

    Public Property MangeTypeID() As Integer
        Get
            Return (Me.TypeId)
        End Get

        Set(ByVal Value As Integer)
            TypeId = Value
        End Set
    End Property

    Public Property ManageTypeName() As String
        Get
            Return (Me.TypeName)
        End Get

        Set(ByVal Value As String)
            TypeName = Value
        End Set
    End Property

    Public Overrides Function ToString() As String
        ' 在此处放置代码
        Return TypeName
    End Function

    Public ReadOnly Property IsNull() As Boolean Implements INullable.IsNull
        Get
            ' 在此处放置代码
            Return m_Null
        End Get
    End Property

    Public Shared ReadOnly Property Null() As UserDefinedType
        Get
            Dim h As UserDefinedType = New UserDefinedType
            h.m_Null = True
            Return h
        End Get
    End Property

    Public Shared Function Parse(ByVal s As SqlString) As UserDefinedType
        If s.IsNull Then
            Return Null
        End If

        Dim u As UserDefinedType = New UserDefinedType
        ' 在此处放置代码
        Select Case s
            Case "1"
                u.TypeName = "数据管理员"
                u.TypeId = 1
            Case "2"
                u.TypeName = "数据输入员"
                u.TypeId = 2
            Case "3"
                u.TypeName = "一般用户" '
                u.TypeId = 3
        End Select
        '        Integer.TryParse(s.ToString, u.V)
        Return u
    End Function

    ' 这是占位符方法
    Public Function Method1() As String
        ' 在此处放置代码
        Return "Hello"
    End Function

    ' 这是占位符静态方法
    Public Shared Function Method2() As SqlString
        ' 在此处放置代码
        Return "Hello"
    End Function

    ' 这是占位符字段成员
    Public m_var1 As Integer
    ' 私有成员
    Private m_Null As Boolean

    Public Shared Function DefaultValue() As UserDefinedType
        Return UserDefinedType.Parse("3")
    End Function

    Public Sub Read(ByVal r As System.IO.BinaryReader) Implements Microsoft.SqlServer.Server.IBinarySerialize.Read

        TypeName = r.ReadString
        TypeId = r.ReadInt16

    End Sub

    Public Sub Write(ByVal w As System.IO.BinaryWriter) Implements Microsoft.SqlServer.Server.IBinarySerialize.Write

        w.Write(TypeName)
        w.Write(TypeId)

    End Sub
End Structure