问题描述
我正在尝试创建一个包含6个表和5个关系的数据集。我在Form_Load事件中创建它。但是我一直收到以下错误...
system.data.dll中发生了'System.ArgumentNullException'类型的未处理异常
其他信息：''column''参数不能为null。
代码在此行停止...
Dim rel_Booking_CaraBook As New DataRelation（" dsFullBooking" ;，dsFullBooking.Tables（" dtBooking"）。列（" Booking ID"），dsFullBooking.Tables（" dtCaraBooking"）。列（" Boo kingID"））
有谁知道我做错了什么？
这是我的完整代码....
Dim dsFullBooking As New DataSet（）
''创建客户数据表
da = New SqlDataAdapter（" SELECT * FROM Client"，Cn）
da.Fill（dsFullBooking，" dtClient"）
''创建预订数据表
da =新SqlDataAdapter（" SELECT * FROM Booking"，Cn）
da。填写（dsFul lBooking，dtBooking）
''创建Caravan_Booking数据表
da = New SqlDataAdapter（" SELECT * FROM Caravan_Booking"，Cn）
da.Fill（dsFullBooking，" dtCaraBooking"）
''创建Room_booking数据表
da =新SqlDataAdapter（" SELECT * FROM Room_Booking"，Cn）
da.Fill（dsFullBooking，" dtRoomBooking"）
''创建Meal_Booking数据表
da = New SqlDataAdapter（" SELECT * FROM Meal_Bookings"，Cn）
da.Fill（dsFullBooking，" dtMealBooking"）
''---------- Relationships
Dim rel_Client_Booking As New DataRelation（" dsFullBooking"，dsFullBooking.Tables
（" dtClient"）。Columns（" ClientID"），dsFullBooking.Tables（" ; dtBooking"）。列（" ClientI D"））dsFullBooking.Relations.Add（rel_Client_Booking）
Dim rel_Booking_CaraBook As N ew DataRelation（" dsFullBooking"，dsFullBooking.Tables
（" dtBooking"）。Columns（" BookingID"），dsFullBooking.Tables（" dtCaraBooking"）。Columns
（" BookingID"））
dsFullBooking.Relations.Add（rel_Booking_CaraBook）
Dim rel_Booking_RoomBook As New DataRelation（" dsFullBooking"，dsFullBooking.Tables
（" dtBooking"）。列（" BookingID"），dsFullBooking.Tables（" dtRoomBooking"）。列
（" BookingID"））
dsFullBooking.Relations.Add（rel_Booking_RoomBook）
''声明datarelation的列（复合键）
Dim RoomBookColumns（4）As DataColumn
Dim MealBookColumns（4）As DataColumn
RoomBookColumns（0）= dsFullBooking.Tables（" dtRoomBooking"）。列（Boo kingID）
RoomBookColumns（1）= dsFullBooking.Tables（" dtRoomBooking"）。Colu mns（Roo mID）
RoomBookColumns（2）= dsFullBooking.Tables（" dtRoomBooking"）。列（" Roo mDt"）
RoomBookColumns（3 ）= dsFullBooking.Tables（" dtRoomBooking"）。列（" Req _Session"）
MealBookColumns（0）= dsFullBooking.Tables（" dtMealBooking"）。列（" ; Boo kingID"）
MealBookColumns（1）= dsFullBooking.Tables（" dtMealBooking"）。Columns（" Roo mID"）
MealBookColumns（2）= dsFullBooking .Tables（" dtMealBooking"）。列（" Roo mDt"）
MealBookColumns（3）= dsFullBooking.Tables（" dtMealBooking"）。Columns（" Req _Session"）
Dim rel_RoomBook_MealBook As New DataRelation（" myRelationName"，RoomBookColumns，
MealBookColumns，True）
dsFullBooking.Relations.Add（rel_RoomBook_MealBook ）
感谢任何帮助
你好翡翠，
你和我一起检查了所有的名字，比如BookingID这主要是一个案例
我做错了。
VB在这种情况下也是大小写的感觉
Cor
Hi, I am trying to create a dataset with 6 tables and 5 relationships created between them. I am creating it in the Form_Load event. However i keep getting the following error...
An unhandled exception of type ''System.ArgumentNullException'' occurred in system.data.dll
Additional information: ''column'' argument cannot be null.
The code stops on this line...
Dim rel_Booking_CaraBook As New DataRelation("dsFullBooking", dsFullBooking.Tables("dtBooking").Columns("Booking ID"), dsFullBooking.Tables("dtCaraBooking").Columns("Boo kingID"))
Does anyone know what im doin wrong??
Here is my full code....
Dim dsFullBooking As New DataSet()
''create the customer datatable
da = New SqlDataAdapter("SELECT * FROM Client", Cn)
da.Fill(dsFullBooking, "dtClient")
''create the booking datatable
da = New SqlDataAdapter("SELECT * FROM Booking", Cn)
da.Fill(dsFullBooking, "dtBooking")
''create the Caravan_Booking datatable
da = New SqlDataAdapter("SELECT * FROM Caravan_Booking", Cn)
da.Fill(dsFullBooking, "dtCaraBooking")
''create the Room_booking datatable
da = New SqlDataAdapter("SELECT * FROM Room_Booking", Cn)
da.Fill(dsFullBooking, "dtRoomBooking")
''create the Meal_Booking datatable
da = New SqlDataAdapter("SELECT * FROM Meal_Bookings", Cn)
da.Fill(dsFullBooking, "dtMealBooking")
''----------Relationships
Dim rel_Client_Booking As New DataRelation("dsFullBooking", dsFullBooking.Tables
("dtClient").Columns("ClientID"), dsFullBooking.Tables("dtBooking").Columns("ClientI D")) dsFullBooking.Relations.Add(rel_Client_Booking)
Dim rel_Booking_CaraBook As New DataRelation("dsFullBooking", dsFullBooking.Tables
("dtBooking").Columns("BookingID"), dsFullBooking.Tables("dtCaraBooking").Columns
("BookingID"))
dsFullBooking.Relations.Add(rel_Booking_CaraBook)
Dim rel_Booking_RoomBook As New DataRelation("dsFullBooking", dsFullBooking.Tables
("dtBooking").Columns("BookingID"), dsFullBooking.Tables("dtRoomBooking").Columns
("BookingID"))
dsFullBooking.Relations.Add(rel_Booking_RoomBook)
''Declare the Columns for the datarelation (for compound keys)
Dim RoomBookColumns(4) As DataColumn
Dim MealBookColumns(4) As DataColumn
RoomBookColumns(0) = dsFullBooking.Tables("dtRoomBooking").Columns("Boo kingID")
RoomBookColumns(1) = dsFullBooking.Tables("dtRoomBooking").Columns("Roo mID")
RoomBookColumns(2) = dsFullBooking.Tables("dtRoomBooking").Columns("Roo mDt")
RoomBookColumns(3) = dsFullBooking.Tables("dtRoomBooking").Columns("Req _Session")
MealBookColumns(0) = dsFullBooking.Tables("dtMealBooking").Columns("Boo kingID")
MealBookColumns(1) = dsFullBooking.Tables("dtMealBooking").Columns("Roo mID")
MealBookColumns(2) = dsFullBooking.Tables("dtMealBooking").Columns("Roo mDt")
MealBookColumns(3) = dsFullBooking.Tables("dtMealBooking").Columns("Req _Session")
Dim rel_RoomBook_MealBook As New DataRelation("myRelationName", RoomBookColumns,
MealBookColumns, True)
dsFullBooking.Relations.Add(rel_RoomBook_MealBook)
any help is appreciated
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