Showing posts with label methods. Show all posts
Showing posts with label methods. Show all posts

Tuesday, March 20, 2012

Best Practice: Procedures: (Insert And Update) OR JUST (Save)

I have a Product Table.

And now I have to create its Stored Procedures.

I am asking the best practice regarding the methods Insert And Update.

There are two options.

1. Create separate 2 procedures like InsertProduct and UpdateProduct.

2. Create just 1 procedure like ModifyProduct. In which programmatically check that either the record is present or not. If present then update and if not then insert. Just like Imar has done in his articlehttp://imar.spaanjaars.com/QuickDocId.aspx?quickdoc=419

Can any one explain the better one.

Waiting for helpful replies.

http://imar.spaanjaars.com/QuickDocId.aspx?quickdoc=419

a

There's no "best practice" for this one. Imar presumably likes his "Save" approach because whether you are adding a new record or amending an existing one, generally software applications ask you to click the Save button - so he likes to make his programming logic analogous.

Personally, I prefer theKISS principal, and create 2 separate procedures. It's clear from the interface which one to call as a result of user action. I also see the decision as to whether to Insert or Update as being a business logic decision, and I'm uncomfortable about putting business logic in a stored procedure. The reason for this is that the business logic may not be transferable to another database platform.

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I do not understand your last point regardgin Business Logic.

I understand that it should be better in your opinion to create 2 separate procedures.

But what about Business Logic Methods.

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zeeshanuddinkhan@.hotmail.com:

I do not understand your last point regardgin Business Logic.

Well, I suppose it depends on how you define "Business Logic". And this illustrates one of the problems with layering an application. The reason why there are so many books and theories on architecture is because there is no "right" way to do it, and definitions of what belongs in which layer are different. Some things so obviously belong in certain layers, but other things might or might not - depending on what you are used to, how you think, what you are told to do by your team leader etc. There is for example, a huge debate about whether stored procedures are a bad thing altogether, because they can be viewed as placing business logic in a database and not in the BLL.

It also depends on how atomic (how much you like to break functionality down into discrete parts - methods, classes, procedures etc) you want your application. Imar would no doubt suggest that the action of the user defines that a Save() method be called, and that while the Save() method can include two alternative actions (Insert or Update), both lead to a row being saved to the database, so it's essentially the same action. The procedure decides whether an existing row is updated or a new one created. I see the difference between Insert and Update as being too different to be combined into one method. Consequently, I break the procedures apart into separate atomic constructs. I view the difference between the 2 as a business logic thing - because I can - and something in my gut tell me it is.

That's purely my view and is neither right or wrong. Others may not agree, and they will no doubt have valid justification for their view. It's right for me but wrong for Imar. And that's why I said at the beginning that there is no Best Practice for Insert or Update v Save. It's purely down to your personal preference. Imar's solution has a certain appeal, in that it contains a certain "cleverness". Some people like that. Nothing wrong with that at all.

Quite often the difference between two alternatives is purely philosophical, and has nothing to do with performance, maintainability or re-useability, which are the three items that Best Practice should be concerned with.

[Edit]

Just re-read my first response and having rambled on above, I see I may have missed your point. If you were asking about transferable business logic, it may be that you have to move the application to a different database system which doesn't support stored procedures, but may support basic INSERT, UPDATE, SELECT and DELETE saved queries. In this case, it wouldn't be too difficult to copy and paste the SQL form each part of the proc, but if you make procs do too much in terms of massaging data, or deciding on a course of action, you will create a load more work in your migration.

You are also perfectly free to ignore this on the basis that "it will never happen". Only you know best.

Thursday, February 16, 2012

Behavior question about updateable resultsets...

I have a question regarding a certain behavior of updateable
resultsets. If I update a column using any of the updateXXX methods and
then try to use the getXXX methods from the same column to see if it
updated the results locally and not on the server, I get the same old
value. I have to call updateRow() but that updates the underlying
database and still gives me the old value until I execute the same
query again and get a new resultset. Maybe the code below will clarify
my question more..
Connection con = null;
Statement stmt;
ResultSet rst;
Class.forName("com.microsoft.jdbc.sqlserver.SQLSer verDriver");
System.out.println("Getting connection.");
con = DriverManager.getConnection(url);
System.out.println("Connection successful.");
String st = "select age,sname,snum FROM student;";
stmt =
con.createStatement(ResultSet.TYPE_SCROLL_SENSITIV E,ResultSet.CONCUR_UPDATABLE);
rst = stmt.executeQuery(st);
rst.last();
System.out.print(rst.getInt(1)+" ");
System.out.print(rst.getString(2)+" ");
System.out.print(rst.getLong(3)+"\n");
rst.updateInt(1,23);
rst.updateRow();
System.out.print(rst.getInt(1)+" ");
System.out.print(rst.getString(2)+" ");
System.out.print(rst.getLong(3)+"\n");
The output is:
Getting connection.
Connection successful.
25 Edward Baker 578875478
25 Edward Baker 578875478
If I were the run the same code again, I get:
Getting connection.
Connection successful.
23 Edward Baker 578875478
23 Edward Baker 578875478
Any/all help is appreciated
Thanks
Devansh Dhutia
University of Iowa
This is a bug and it does not have a trivial fix. I would like to encourage
you to file this using the product feedback website (below).
The problem here is that there are two mutually exclusive places where
column values transit through the driver. The first, used only by getters,
is through the columns array (lives on the statement). The second, used
only by setters, is through the colParam array (also lives on the
statement). The columns array is read only the colParam array is write
only...
Note that the JDBC spec provides (in section 27.1.22, p. 718 - 719 JDBC API
Tutorial and Reference, Third edition, (Fisher, Ellis, Bruce)) that a result
set's own updates need not be visible to it. Obviously we would not like
this to be the default behavior but it is going to take a lot of work and it
would help to have customer feedback that clarified why this behavior should
be changed.
Entering a bug:
Go to http://lab.msdn.microsoft.com/produc...k/default.aspx
Product/Technology:
SQL Server 2005
Category:
JDBC Driver
Make sure to add JDBC SqlServer 2005 to the but title.
Angel Saenz-Badillos [MS] DataWorks
This posting is provided "AS IS", with no warranties, and confers no
rights.Please do not send email directly to this alias.
This alias is for newsgroup purposes only.
I am now blogging: http://weblogs.asp.net/angelsb/
<devansh.dhutia@.gmail.com> wrote in message
news:1128188361.813553.300740@.g47g2000cwa.googlegr oups.com...
>I have a question regarding a certain behavior of updateable
> resultsets. If I update a column using any of the updateXXX methods and
> then try to use the getXXX methods from the same column to see if it
> updated the results locally and not on the server, I get the same old
> value. I have to call updateRow() but that updates the underlying
> database and still gives me the old value until I execute the same
> query again and get a new resultset. Maybe the code below will clarify
> my question more..
> Connection con = null;
> Statement stmt;
> ResultSet rst;
> Class.forName("com.microsoft.jdbc.sqlserver.SQLSer verDriver");
> System.out.println("Getting connection.");
> con = DriverManager.getConnection(url);
> System.out.println("Connection successful.");
> String st = "select age,sname,snum FROM student;";
> stmt =
> con.createStatement(ResultSet.TYPE_SCROLL_SENSITIV E,ResultSet.CONCUR_UPDATABLE);
> rst = stmt.executeQuery(st);
> rst.last();
> System.out.print(rst.getInt(1)+" ");
> System.out.print(rst.getString(2)+" ");
> System.out.print(rst.getLong(3)+"\n");
> rst.updateInt(1,23);
> rst.updateRow();
> System.out.print(rst.getInt(1)+" ");
> System.out.print(rst.getString(2)+" ");
> System.out.print(rst.getLong(3)+"\n");
> The output is:
> Getting connection.
> Connection successful.
> 25 Edward Baker 578875478
> 25 Edward Baker 578875478
> If I were the run the same code again, I get:
> Getting connection.
> Connection successful.
> 23 Edward Baker 578875478
> 23 Edward Baker 578875478
> Any/all help is appreciated
> Thanks
> Devansh Dhutia
> University of Iowa
>