|
If both of the following are true then it could be relevant.
1. High volume system.
2. Many columns of this type. (Really high volumes even a couple might be relevant.)
However since the vast majority of systems will never have both of these it isn't going to be relevant.
Mycroft Holmes wrote: and the dba/developers/coder/us lazy bastards do not need to test for null values.
And maybe a bit stupid too since zero and null are not necessarily the same thing.
|
|
|
|
|
jschell wrote: since zero and null are not necessarily the same thing
The is always a debating point, do we allow null to represent a value in a numeric field?
As I'm a lazy sod I disallow null in numeric field as my default position and until the business can convince me otherwise that is the way it is designed.
Never underestimate the power of human stupidity
RAH
|
|
|
|
|
Thanks guys answers my question!
|
|
|
|
|
Can some one explain to me what a Staging area is ?
And I also want to know whether it is a database, a file, or something else altogether..?
|
|
|
|
|
Here are some answers: What is a staging area? Do we need it? What is the purpose of a staging area?[^].
Right now I'm using staging tables to temporarily store data imported from an outside source before pushing it to production so that it can be verified in isolation and altered as required.
"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair.
nils illegitimus carborundum
me, me, me
|
|
|
|
|
So you are using a staging area which is in between development and production phases. You said this staging area was a set of temporary tables. Can it be a whole separate database by itself? And if it is a database how do we make it temporary(as in what is its scope)?
And whatever operations you do on the staging area do you write the code for it or generate it using code generators?
PS: Don't mind the long question?
|
|
|
|
|
No, I said the data was temporarily stored: the tables are a permanent fixture and are used to transition that data before it gets exposed in the production tables. For my purposes it's okay for the tables to reside in the prod database but that might not suit you. There is no reason it can't be a wholly separate database: that's up to you and the requirements.
All of the code is either in stored procedures and/or c#. The usual scenario is that the tables are truncated and (in my case) filtered data is dumped into them and then other processes may work on them and then the data is moved to the primary tables.
Note that this is just how our solution works for us: it may not be right for you. Use anything like this with extreme caution, especially near production data.
"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair.
nils illegitimus carborundum
me, me, me
|
|
|
|
|
Aha that gives a lot of clarity....So these staging tables ...are they exact replica of production tables or do we have to follow some separate design principles to create them?
|
|
|
|
|
In my case they are straight copies of the production table but with all indexes, etc removed. Again, that suits my purpose. May not suit yours.
"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair.
nils illegitimus carborundum
me, me, me
|
|
|
|
|
We do it somewhat different to Mark, our staging table are exact replicas of the source data, this allows us to use Bulk Copy when loading the data. It also insures there are no errors in the Load part of the ELT process.
We then use stored procedures to do the transforms to the production format (these may also be staging tables in some solutions). The major benefit is that you are doing any transforms on a limited data set and it is easy to debug the procedure. It then becomes a simple matter to dump in the staging data to the production tables.
I find a well crafted ELT process leave any ETL application in the dust. There are some ETL apps that this may not apply to but the cost is extraordinary.
Never underestimate the power of human stupidity
RAH
|
|
|
|
|
Mycroft Holmes wrote: our staging table are exact replicas of the source data, this allows us to use
Bulk Copy when loading the data. It also insures there are no errors in the Load
part of the ELT process.
I do the same thing, works great plus if there are any questions about the source data you already have a loaded copy in a table to query against.
Common sense is admitting there is cause and effect and that you can exert some control over what you understand.
|
|
|
|
|
The second greatest scam after Y2K that the IT industry has ever perpetrated is ETL! Extract - Load - Transform simplifies and speeds up the entire process.
Never underestimate the power of human stupidity
RAH
|
|
|
|
|
Mycroft Holmes wrote: The second greatest scam
I have worked for some CIO's that have come up with way more atrocities than ETL or Y2K.
Mycroft Holmes wrote: Extract - Load - Transform simplifies and speeds up the entire process.
I think you can write bad code / processes in any language or tool. It's up to the person to find the best way to do it that works for them. Not sure about you but I have some amazingly fast SSIS packages that load a gig of data in seconds, but have seen some others that take hours doing a lot less data.
Common sense is admitting there is cause and effect and that you can exert some control over what you understand.
|
|
|
|
|
Hi
To learn entity frame work
Do I need to learn linq?
thank you
|
|
|
|
|
that could be quite handy
In Word you can only store 2 bytes. That is why I use Writer.
|
|
|
|
|
Hello All,
If I use a try-catch block in my stored proc, and in the catch block write error to table, do I need to use BEGIN TRANSACTION - COMMIT TRANSACTION to get the try-catch block to work?
I am using -
BEGIN TRY
write my code here
END TRY
BEGIN CATCH
write my code here
END CATCH
But should be - to write errors to a log table.
BEGIN TRY
BEGIN TRANSACTION
write code here
COMMIT TRANSACTION
END TRY
BEGIN CATCH
write code here
END CATCH
|
|
|
|
|
no you do not have to(but it is a safer option)..Have a look at the following snippet..-
USE AdventureWorks2008R2;
GO
-- Variable to store ErrorLogID value of the row
-- inserted in the ErrorLog table by uspLogError
DECLARE @ErrorLogID INT;
BEGIN TRY
BEGIN TRANSACTION;
-- A FOREIGN KEY constraint exists on this table. This
-- statement will generate a constraint violation error.
DELETE FROM Production.Product
WHERE ProductID = 980;
-- If the delete operation succeeds, commit the transaction.
COMMIT TRANSACTION;
END TRY
BEGIN CATCH
-- Call procedure to print error information.
EXECUTE dbo.uspPrintError;
-- Roll back any active or uncommittable transactions before
-- inserting information in the ErrorLog.
IF XACT_STATE() <> 0
BEGIN
ROLLBACK TRANSACTION;
END
EXECUTE dbo.uspLogError @ErrorLogID = @ErrorLogID OUTPUT;
END CATCH;
-- Retrieve logged error information.
SELECT * FROM dbo.ErrorLog WHERE ErrorLogID = @ErrorLogID;
GO
|
|
|
|
|
Can someone answer these following questions:-
What is FaultException (WCF related)?
When does it occur; as in, is it a problem related to service configurations or is it an error in program logic?
|
|
|
|
|
|
The thing is I went there before I came here. I want some meaty explanation(from practical experience) rather than the cut and dried documentation provided by Microsoft.
PS:Seeing those huge tables and lists at the start of the page itself was a huge turnoff. 
|
|
|
|
|
Hi All ... in my form app. i have textboxs related databindings yonet_ogrt and I have 2 datagridview yonet_prg
and yonet_nbt.. so I want to all together navigate but textboxs and datagridview related yonet_prg is working but
datagridview related yonet_nbt not working... this is my trouble...
My code like this...
public void vt_iliski()
{
try
{
string sorgu_ogretmen = "select * from ogretmen";
string sorgu_program = "select * from program";
string sorgu_nobet = "select * from nobet";
ds_gnd = new DataSet();
DataTable tablo = new DataTable();
adpt_ogrt = new SqlCeDataAdapter(sorgu_ogretmen, baglan());
adpt_prg = new SqlCeDataAdapter(sorgu_program, baglan());
adpt_nbt = new SqlCeDataAdapter(sorgu_nobet, baglan());
adpt_ogrt.Fill(ds_gnd, "ogretmen");
adpt_prg.Fill(ds_gnd, "program");
adpt_nbt.Fill(ds_gnd, "nobet");
/* ********** relation -1 ****************** */
DataColumn ogrt_kolon = ds_gnd.Tables["ogretmen"].Columns["ogrt_ID"];
DataColumn prg_kolon = ds_gnd.Tables["program"].Columns["ogrt_ID"];
iliski1 = new DataRelation("Ogretmen_To_Program", ogrt_kolon, prg_kolon);
ForeignKeyConstraint kisitla = new ForeignKeyConstraint(ogrt_kolon, prg_kolon);
kisitla.UpdateRule = Rule.Cascade;
kisitla.DeleteRule = Rule.Cascade;
kisitla.AcceptRejectRule = AcceptRejectRule.Cascade;
ds_gnd.Tables["program"].Constraints.Add(kisitla);
ds_gnd.EnforceConstraints = true;
ds_gnd.Relations.Add(iliski1);
yonet_ogrt = new BindingSource(ds_gnd, ds_gnd.Tables["ogretmen"].ToString());
yonet_prg = new BindingSource(yonet_ogrt, "Ogretmen_To_Program");
/* ********** relation-2 ****************** */
DataColumn prg_kolon_nobet = ds_gnd.Tables["program"].Columns["prg_ID"];
DataColumn nobet_kolon = ds_gnd.Tables["nobet"].Columns["prg_ID"];
iliski2 = new DataRelation("Program_To_nobet",prg_kolon_nobet , nobet_kolon );
ForeignKeyConstraint kisitla2 = new ForeignKeyConstraint(prg_kolon_nobet, nobet_kolon);
kisitla2.UpdateRule = Rule.Cascade;
kisitla2.DeleteRule = Rule.Cascade;
kisitla2.AcceptRejectRule = AcceptRejectRule.Cascade;
ds_gnd.Tables["nobet"].Constraints.Add(kisitla2);
ds_gnd.EnforceConstraints = true;
ds_gnd.Relations.Add(iliski2);
yonet_prg = new BindingSource(ds_gnd, ds_gnd.Tables["Program"] .ToString());
yonet_nbt = new BindingSource(yonet_prg , "Program_To_nobet");
}
catch (Exception hata)
{
MessageBox.Show("Okul Günlük Nöbet Defteri iliskilendirme Hatasi olustu : " + hata.Message + " " + hata.StackTrace );
}
finally
{
baglanti.Dispose();
adpt_ogrt.Dispose();
adpt_prg.Dispose();
adpt_nbt.Dispose();
}
|
|
|
|
|
|
The following subquery returns 1024 records with a single count column. I am trying to return multiple columns with 1024 records. When I make changes to return multiple columns I get 17,000 records instead of 1024 records. I have very litle experience with subqueries. Does anyone have any suggestions?
SELECT IFNULL(COUNT(DISTINCT A.computerid),0) AS 'Machine Count',
A.hotfixID AS 'Last Contact'
FROM (SELECT HF.computerid, HF.hotfixID
FROM hotfixdata HFD
INNER JOIN hotfix HF
ON HF.hotfixid = HFD.hotfixid
AND HFD.ignore <> 1
LEFT OUTER JOIN Computers AS C
ON C.ComputerID=HF.ComputerID
WHERE INSTR(C.os,"microsoft")>0
AND HF.installed <> 1
AND HF.Approved = 1
GROUP BY HF.hotfixID, HF.ComputerID) A;
|
|
|
|
|
|
I have a class and the data in it has to be stored in the database. I have done this by extracting every single property and sending each of them as input parameters to a stored procedure in the database. But the thing is that the class has too many properties. Is there any way to accomplish this in a single go(lesser amount of code)? OH and I am using C# and Sql Server!
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
