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If I have a DataRow and a foreign key constraint (1:N), is there a way to get a DataTable with all of the childs of the relationship?
e.g. if I have
DepartmentDataTable dep = ...
EmployeeDataTable emp = ...
ForeignKeyConstraint fk = new ForeignKeyConstraint(dep.IDColumn, emp.DepartmentIDColum);
DepartmentRow hq = dep.FindByID(666);
EmployeeDataTable allHQEmployees = magic</>(hq, fk);
?
Developers, Developers, Developers, Developers, Developers, Developers, Velopers, Develprs, Developers!
We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
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Have you tried using the DataRow.GetChildRows() method? If you define a DataRelation instead of a ForeignKeyConstraint (which will be added along with the DataRelation) you can use DataRow.GetChildRows() to get a DataRow[] reference. Once you have DataRow[] you could instantiate a new EmployeeDataTable and copy DataRow[] into the new data table using the DataTable.ImportRow() method.
You could alternatively do something using a DataView, sort by DepartmentID and call DataView.FindRows(), then perform the same copy operation I mentioned above.
But other than creating a new table object and copying rows from one table to the next there is no way to return a new data table based on a "filter" of an existing table.
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If I call GetData() on an System.Data.OleDb.OleDbAdapter, does that actually read all data from the database?
Or does it just open the rowset, and the data is read only when I access the actual rows?
Developers, Developers, Developers, Developers, Developers, Developers, Velopers, Develprs, Developers!
We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
Linkify!|Fold With Us!
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System.Data.OleDb.OleDbAdapter doesn't exist, but System.Data.OleDb.OleDbDataAdapter does. But it doesn't have a GetData() method, it has a fill method which loads a disconnected dataset or datatable will all the results of the query and then disconnects (if the connection was closed before Fill() was called.
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Is it possible to have a constraint that depends on a column value? For instance, I would like my DocUpdate table to require NewDocStatus is not null when IsStatusUpdate = 1, but allow NewDocStatus to be null in other records.
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Using a check constraint you can do the following:
<br />
CREATE TABLE myChkTable (IsStatusUpdate BIT, NewDocStatus VARCHAR(25))<br />
go<br />
<br />
ALTER TABLE myChkTable ADD CONSTRAINT chkTblConstraint CHECK (<br />
(IsStatusUpdate = 1 AND NewDocStatus IS NOT NULL) OR IsStatusUpdate = 0<br />
)<br />
go<br />
<br />
--the first three will succeed<br />
INSERT INTO myChkTable VALUES (0, null)<br />
INSERT INTO myChkTable VALUES (1, 'status')<br />
INSERT INTO myChkTable VALUES (0, 'not update')<br />
<br />
--this will fail<br />
INSERT INTO myChkTable VALUES (1, null)<br />
<br />
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I don't mean to sound stupid.
But what does the term "MRD" stands for in SQL Server?
Does anybody know?
Thanks.
R
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Hi,
For the life of me, I haven't been able to figure the following out and I hoping someone out there can offer some good advice.
I have an ASP page that lists a lot of manuals and their associated new features for that particular release.
For example:
Manual title New Feature
manual 1 new feature1
manual 1 new feature2
manual 1 new feature3
manual 2 new feature1
manual 3 new feature1
manual 3 new feature2
Rather than have the same manual listed consecutively with a different new feature association, I would like to list the results as such:
Manual title New Feature
manual 1 new feature1
new feature2
new feature3
manual 2 new feature1
manual 3 new feature1
new feature2
Is this possible using ASP and SQL?
Here's the stored procedure:
<code>CREATE PROCEDURE [docadmin1].[sp_view_nfprodrel]
@product nvarchar (250)
AS
SELECT distinct top 100 Percent doc_id, title, relnum, substring(dn,3,14) as DN, product, New_Feature FROM nf_prodrel_man WHERE product = @product order by Title
GO</code>
Here's the view being called from the stored procedure:
<code>CREATE VIEW dbo.nf_prodrel_man
AS
SELECT TOP 100 PERCENT dbo.Books.Title + ' ' + dbo.Books.Rel_Num AS title, dbo.PROD_REL.Product, dbo.DOC_RELATIONSHIP.Doc_ID,
dbo.New_Feature.NF_ID, SUBSTRING(dbo.New_Feature.New_Feature, PATINDEX('% %', dbo.New_Feature.New_Feature),
LEN(dbo.New_Feature.New_Feature)) AS New_Feature, dbo.Books.DN, dbo.New_Feature.Description, RIGHT(dbo.PROD_REL.Product, 3)
AS RELNUM
FROM dbo.PROD_REL INNER JOIN
dbo.NF_PROD_REL ON dbo.PROD_REL.Prod_Rel_ID = dbo.NF_PROD_REL.Prod_REL_ID INNER JOIN
dbo.New_Feature ON dbo.NF_PROD_REL.NF_ID = dbo.New_Feature.NF_ID INNER JOIN
dbo.DOC_RELATIONSHIP ON dbo.NF_PROD_REL.REL_ID = dbo.DOC_RELATIONSHIP.REL_ID INNER JOIN
dbo.Books ON dbo.DOC_RELATIONSHIP.Doc_ID = dbo.Books.Doc_ID
ORDER BY dbo.Books.Title + ' ' + dbo.Books.Rel_Num, dbo.PROD_REL.Product</code>
Thanks in advance!
Regards,
Jenn
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It is possible to do this in SQL, but it is much easier to acheive in the ASP page (especially as it is a presentation thing). The structure would look a bit like:
lngOldBookId = -1
For Each objRec In arrBookList
Response.Write("<tr><td>")
If lngOldBookId <> objRec.BookId Then
Response.Write(objRec.Title)
lngOldBookId = objRec.BookId
Else
Response.Write(" ")
End If
'write other bits of result table.
NextSo you only print a book title when it is different from the previous record.
Hope that helps.
Andy
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Thanks Andy. I will give a try and let you know how I fare.
Have a great day,
Jenn
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I normalized a table in a database project I'm working on so that instead of having something like this:
Table: entities
-----------------
ID NAME RELATED_ITEM_ID_1 RELATED_ITEM_ID_2 ..... RELATED_ITEM_ID_40
1 Entity 1 1 24 67
2 Entity 3 14 NULL 45
I now have something like these two tables:
Table: entities
-----------------
ID NAME
1 Entity 1
2 Entity 3
Table: entity_items
-----------------
ENTITY_ID RELATED_ITEM_ID
1 1
1 24
1 67
2 14
2 45
I want to return a table that has a summary of the entities table returning the top three entity_items so that it will come back looking like the original (non-normalized) entities table.
I am using a MySQL database, but any help with the basic concepts and SQL here would be appreciated. I'm sure this is a common problem people deal with, but I didn't even know the terminology to use to find an answer on the web.
Thanks.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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Thank you. That was helpful.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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Hello!
I can't execue the following sql string because I am getting an error message. How can I increment the specific field in the table by one?
SQLSTR = "UPDATE setup SET TotalUser=TotalUser + 1 WHERE RecordNumber = 1"
Thanks 
Journey
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B Journey wrote: I can't execue the following sql string because I am getting an error message.
What is the error message?
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SQLSTR = "UPDATE setup SET TotalUser=TotalUser + 1 WHERE RecordNumber = 1"
Call Initialize_Connection()
Call Execute_Statement(SQLSTR) ' the error occurs in this procedure
the procedure content is here:
Sub Execute_Statement(GetSQL)
Set ObjectRecord = Server.CreateObject ("ADODB.Recordset")
ObjectRecord.CursorLocation = adUseServer
ObjectRecord.CursorType = adOpenkeyset
ObjectRecord.LockType = adLockOptimistic
ObjectRecord.Open GetSQL, ObjectConnection,,, adCmdText 'error points this line
End Sub
Thanks
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Okay - so at least we now know WHERE the error is. You still have not told us WHAT the error is.
What is the error message?
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Sorry! Here is the error message. I have double checked all fields in the table nothing looks wrong. It is working on my local server but when I transfer it to server in Internet, I am getting this error message.
Microsoft JET Database Engine error '80040e10'
No value given for one or more required parameters.
/emlak/include/scripts.inc, line 138
I have included the procedure in my previous message where the error is pointing the line 138.
Thanks
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That's a typical error when you have misspelled one of the column names (e.g. TotalUsers or RecordNumber)
Developers, Developers, Developers, Developers, Developers, Developers, Velopers, Develprs, Developers!
We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
Linkify!|Fold With Us!
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Try using an ADODB.Command object instead of a recordset. You are performing an update.
the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer
Deja View - the feeling that you've seen this post before.
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That update should work. I would guess that either you don't have rights to update the setup table. Or you need to better qualify the setup table. Perhaps there is a dbo.setup table and a username.setup table. It is always a good idea to qualify your table names. If it isn't that most likely it is a security thing, the user that is running the update doesn't have update rights on that table. If you provided the error message we might be able to pin point the issue.
Hope that helps.
Ben
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Please refresh my rusty SQL skills. I have a DocMaster table with Status and StatusTime fields, and I have a DocUpdate table with UpdateTime and DocStatus fields. The DocUpdate table stores a history of all status updates for a document, and the DocStatus and StatusTime fields in the DocMaster table are redundant copies of the UpdateTime and DocStatus fields for the most recent DocUpdate record for a given document. How do I update the DocMaster table to correct the values in these fields?
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Hi Brad
Normally you would use a trigger to keep the two tables synchronised. If the tables are currently out of sync then the following should fix the master table:
update DocMaster set
DocStatus = A.DocStatus,
UpdateTime = A.UpdateTime
from DocUpdate A
where A.DocId = DocMaster.DocId
and A.UpdateTime = (select max(UpdateTime) from DocUpdate
where DocUpdate.DocId = DocMaster.DocId)This assumes that the primary key on DocMaster is named "DocId", and that the "UpdateTime" is unique for each document (if you have an identity column on DocUpdate then you should use that instead).
Hope that helps.
Andy
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That's perfect, thanks Andy. I do have triggers doing the normal sync work, but whenever I create redundant or derived fields like these I always start with an update procedure that makes everything all good again, if something goes wrong.
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Hi friends
What is a clustered index? How many records can take clustered index in sql server?
what is a cursor?
what is a sql injuction?
thanks in advance
khan
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