Characteristics Of Primary Key In The Table?
Oct 24, 2009
I would like to have some explaination about the characteristics of a primary key in the table of such database. This is for vb 2008 express edition,since im new to this language,if this is true, as far as i understand about the characteristic in setting the primary key on each field for true.My question is if you are doing an updates/edit records in your table using the DataContext,if you setup the primary key for true of one of your field in the table it would edit all records in one datarow but if you put the primary key for true in all fields except one of them,all the records in the data column of that field which primary key is false could be edited.Basically its impossible to edit all records in the datarow and all the records in the datacolumn of the table in such one event. Is there any further explaination about the characteristics of primary key in the table?
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Oct 24, 2009
I would like to have some explaination about the characteristics of a primary key in the table of such database.This is for vb 2008 express edition,since im new to this language,if this is true, as far as i understand about the characteristic in setting the primary key on each field for true.My question is if you are doing an updates/edit records in your table using the DataContext,if you setup the primary key for true of one of your field in the table it would edit all records in one datarow but if you put the primary key for true in all fields except one of them,all the records in the data column of that field which primary key is false could be edited.Basically its impossible to edit all records in the datarow and all the records in the datacolumn of the table in such one event.Is there any further explanation about the characteristics of primary key in the table?
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May 8, 2012
After days of labouring, debugging and researching, im on the 3rd to last line and im stuck. This isnt the full code, but the relevant parts.
Dim dbProvider As String
Dim dbSource As String
Dim con As New OleDb.OleDbConnection
[Code].....
I understand this means my table doesnt have a primary key, but i have set one.
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Aug 3, 2009
I have an access database with 4 tables and two of the tables have absolutely no need for a unique field that would be a primary key. One will only have one record and the other is a detail table for two master tables. I of course get an error like "UpdateCommand is not supported against a SelectCommand that does not return any key column information." when I try to save. Do I have to just create a primary field key I don't need or is there a work around for this?
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Mar 17, 2011
[Code]....
It is returning all the columns by id. I need only the primary key. When I add the following line it is empty: WHERE SIK.indid = 1 Why is that? Is there other ways to do the same thing and working? Since I am in the rush
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Jun 10, 2011
I'm having some problems trying to input records into a relational database. The design is really simple but I'm running into a wall when it comes to having the foreign key from my child table autopopulate the primary key from the parent table. I've made the connections in Access and from what I understood, so long as I committed a transaction, the child table would populate the primary key from the parent table. This is not happening.
my question is: is there a method that would do what I'm looking for? or am I cornered into using @@IDENTITY and manually inserting the primary key into the child table?
I've tried using datasets and data adapters and created a datarelation within the dataset, but it is still not doing what I need. everything I've tried thus far has allowed me to insert records into multiple tables, but won't relate them because of the missing primary key in the child table.
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Jun 8, 2011
So I have a program that I am converting to .NET FW 3.5 and I am getting the titled exception on the following line:If IsNothing(dsTopPI.Rows.Find(profile.Item("GEMSID"))) Then Continue For
which is in a for each loop. The thing is, I have set the primary key and when I put in the following code:Dim columns() = DSTop30Profiles1.DTtop30profiles.PrimaryKey Console.WriteLine("Column count: " & columns.Length.ToString)For a = 0 To columns.GetUpperBound(0)Console.WriteLine(columns(a).ColumnName & " - " & columns(a).DataType.ToString)Next
I get this in the output:Column count: 1 GEMSID - System.Int32
That would seem to indicate that there is in fact a primary key, right?
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Aug 23, 2010
Storage Unit application, 5 buildings, 107 Units split between the 5 buildings.frmBuildings is a form with:(from the botton up) 1 TLP 5 columns 2 rows5 Group Boxes, 1 per column, Group Box 1 & 2 each have a TLP with 2 columns & 3 rows. 107 buttons on the form that represent each building.The idea is that I want to change the BackColor of any button that represents an Available unit. This is a multi tier applaicationData Access Layer query function:
' Method name: getStorageUnitsAvailable
' Purpose: to return a Data Table from data base
' Parameters: none
[code].....
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Jan 18, 2010
How would i get the primary key id number from a Table WITHOUT making a second trip to the database in LINQ To SQL?
right now, i submit the data to a table, and make another trip to figure out what id was assigned to the new field (in an auto increment id field). I want to do this in LINQ To SQL and not in Raw SQL (I no longer use Raw SQL).
also, seond part of my question is: i am always careful to know the id of a user thats online because i'd rather call their information in various tables using their id as opposed to using a guid or a username, which are all long strings... i do this because i think that SQL Server doing a numeric compare is much (tentative use of the word 'much') more efficient than doing a username (string) or even a guid (very long string) compare.
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Mar 7, 2009
I hope someone can help me. I have an ATM machine connected to a server. A form takes a textBox entry as a PIN number and matches it to a card number in the same table which is the primary key. The card number is in a comboBox.Selected Item. I have used a dataset to fill the comboBox as the form loads. I have tried for days and got nowhere.
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Mar 15, 2010
What's the syntax for an Update query for a table without a primary key?Disclaimer: Frustratingly, adding a primary key is not an option. My program is a small program in a much larger system with poor data management. My development time does not include rewriting the other software.
Note: The database is Microsoft Access.
Note: Similar to: Excel: TableAdapter UpdateCommand for table without primary key
UPDATE: Am I correct in saying, "If the table in the database has no explicit primary key, then there can be no valid TableAdapter UpdateCommand?"
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Mar 8, 2010
Ok i have 3 tables in a dataset
Table1 contains items for sale (referenced)
Table2 contains Stores (Parent)
Table3 Contains items in a particular store (Child)
the problem is the data in this case. Table 2 contains a StoreId field as a primary key. Table1 Contains an ItemId field. My problem is in table 3 this contains 3 fields, StoreId, Name and Quantity.
Now my Table1 contains a field called Name and one called PluralName, I need to determine which field in table one relates to the Name field in table3.
The following 2 constraints exist currently in my app
Table2 - StoreId (one) to Table3 - StoreId (many)
Table1 - Name (one) to Table3 - Name (one)
can i add another constraint :- Table1 - PluralName (one) to Table3 - Name (one) ???
I am presuming if i do i will get a constraint error as the property does not relate on a one to one level if the store has more than one item in stock and vice versa when it has only one in stock.
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May 1, 2012
I'm looking for in depth information about Visual Basic. For example, Scoping and binding behaviors, subprogram and package facilities, etc.
Edit:I'm looking for information such as: VB uses lexical or dynamic scoping; binding for X happens at compile time/load time/runtime and is static or dynamic. Basically a more in depth look at the characteristics of the language.
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Aug 9, 2011
I am trying to append multiple rows in a SQL Server.I have connected to the MS SQL Server and with a DataAdapter, I have downloaded the Table into a DataTable and displayed it in DataGridView.I now want to programatically enter multiple rows into the DataTable and later to update the SQL Table.
I am trying to build an application to do this generically.The problem I have is that the Table and DataTable has an 'ID' Field. In the SQL DB, i is an Auto-incrementing field.When the code loops through creating new rows and entering field values, how do I handle the ID Field that is the Primary Key?
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Jul 20, 2009
I am using a number of tables on my application and two of which have a foreign key constraint I have set between them. When I change the account number on the main table via a combo box all of the relevant information for that table on the form is updated accordingly. However, the child table which has a foreign key reference to the Account Number of the main table is not updated when the acocunt number is changed. I have set the update to cascade in the references but still am having issues.
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May 26, 2011
I defined a database using SQL Server 2008 R2 Express, and connected to it using Visual Basic 2010 Express. For some reason though, when I use the database in the program, it wants to start off using a negative primary key.Is there any way to make the primary key only a positive number?
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Oct 11, 2009
I have a table with a multiple columns (two) primary key. I get an error on tableadapter.Update .How can I resolve that??
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Aug 23, 2011
On a client i have an anonymous list containing a multi-column primary key previously selected from the DB.Then i need to select all the records from the DB that equals the primary key list i have stored in the memory.[code]
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Mar 2, 2012
How i can import row from TABLE1 to TABLE2 without primary keyfield or adding correct value to primary key
i tried with two different codes, but result is same, it says: "In the column "Key"a constraint on the uniqueness.[code]...
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Apr 15, 2009
I am having major problems with creating my tables and populating them.The problem for the creating seems to lie when I try to create my table named WeeklyUnitStaffRota. I get the run time error 2147467259(80004005) No unique index found for the referenced field of the primary table. This has only started happening as I have been tinkering with my tables to get them to populate properly.I seem to have a problem when I have two columns with the same info but relating to a different college ie two MSC being run at 2 different colleges.[code]...
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Jul 18, 2012
i'm trying to do some appointment book so i decided to use MonthCalendar control and date changed event for choose the date i tried dataset.table.rows.find() function on other tables which have int primary key and it works its finds my row/s i need but when i tried this func. on date type primary key it cannot find i tried to search with date type ==> fail search with string type like 03.07.2012 ==> failed etc.
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Aug 30, 2009
I want to add a new table in my accdb and copy the content tfrom an existing table into the new one.
Is there an easy way to do this?
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Dec 21, 2011
I have a data table whose one column is related to a column of another table. I have a listbox in a form which shows a column (which is sorted by another column value by ORDER clause) of the parent table and other columns are in textboxes. The child table is represented by a datagrid. When I add a new item in parent table and click save, the newly created item is listed at the bottom of the listbox violating my ORDER clause. When I wrote some codes to fill data again after updating, it shows an error message[code]...
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Oct 5, 2011
Is it possible to have a Foreign Key as the Primary Key?
<Key()>
Public Property AssignmentID() As Integer
<ForeignKey("AssignmentID")>
Public Overridable Property Assignment As Assignment
Public Overridable Property User As User
For the code above I get an error:One or more validation errors were detected during model generation:System.Data.Edm.EdmAssociationEnd: : Multiplicity is not valid in Role 'AssignmentLocks_Assignment_Source' in relationship 'AssignmentLocks_Assignment'. Because the Dependent Role refers to the key properties, the upper bound of the multiplicity of the Dependent Role must be �1�.
I'm trying to create a table which has one (or none) record per assignment.
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Apr 15, 2010
I have a database running on SQL server primary key is all set, my question is i dont want to allow duplicates in the primary key, i want everything to be uniqure. The database already has information in it, is there a away to set it so when i add a new row through the table adapter that it will recognise the last primary key value and increment it by +1?
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Jun 6, 2011
i has create system registration that use vb.net 2008 & accessdatabase (oledb connection).i set ID
as primary key,when i insert new ID but if ID already in database i will get error cz data
duplicates..so anyone know any code that will promp mesej like this "Data already in data base,
insert ID corectly" if data already in accessdatabase.
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May 11, 2011
I'm currently using this to get an object by it's primary key value.
I'm trying to find a way to create a similar method GetByIDs where I can pass an IEnumerable(of object) and do ids.contains(pk), but there's no Contains expression.
Public Function GetByID(Of T As Class)(ByVal pk As Object) As T
Dim itemParam = Expression.Parameter(GetType(T), "item")
Return GetTable(Of T).Single(
[Code].....
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Jul 18, 2011
I' m trying to get the primary key which is "TestID" through the code below but I get an error "Range variable "testid" hides a variable in an enclosing block or a range variable previously defined in the query expression." What does this error mean ?
Dim oo As New DataClassesDataContext
Dim o = (From k In oo.Tests
Where k.Category.Equals(tempcategory) And k.Level.Equals("1")
[code]....
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Mar 15, 2012
i am trying to make a customer registration form. On the form i want to display the employee ID or Employee name who is servring or registring the customer. In short the employee who is logged in the system ,his Name or id should appear in the customer registration text box where the label says "served by"txtEmpName.Text
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Mar 11, 2009
How do i reset a primary key to "0" at midnight For Every Day of the week. I would like To Start a fresh day @ "0" But keep The Information the I have. Previously Put in (it is For a booking program I am trying to create)
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