Create a view based on a view

I am editing a created view, VIEW_B. When I looked at the code, it is selecting from another view, VIEW_A.
VIEW_A : Select * from Emp
VIEW_B : Select * from VIEW_A where sal > 1000
Is it advisable to continue having a view selecting from another view or is it better for VIEW_B to be Select * from Emp where sal > 1000? I tried doing both and the performance was the same. However, I do not know if this will work with all of the views created that I need to edit, if there are factors that affect performance.
If you guys know any documentation on this or have any experience regarding this matter, please let me know.
Thanks!

it depends and there is no standard approach as to when a view should include another view. mostly i see this approach whenever grouping is needed. this is to say that one view is a grouping of mostly related columns and creating another view to include that view which has the grouping. i observed that is an approach that some developers use instead of using a inline views - the sub-query part that is use in the FROM clause. the same view can be use to other codes without having to re-type the sub-query.

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How to create ADF UI based on polymorphic view objects

Hi,
I'm using JDeveloper build JDEVADF_11.1.1.3.PS2_GENERIC_100408.2356.5660. I created a simple application based on Steve's example #10 [url http://blogs.oracle.com/smuenchadf/examples/]ViewRow and EntityObject Polymorphism.
I added a men-only attribute "Age" to the "Men" VO and filled it with an arbitrary value in MenRowImpl.java:
public String getAge() {
return (String) "45";//getAttributeInternal(AGE);
}Running the TestModule works perfectly - a row of type "Men" displays the "Age" attribute whereas a row of type "Women" doesn't.
Afterwards, I setup an ADF ViewController Project and created a JSPX with a read-only form based on the "People" datacontrol with navigation buttons. Running that page always shows the same set of attributes independent of the row type. That's expected behaviour because the binding is defined at design time.
So my question is: can I somehow achieve the same behaviour for polymorphic VOs as the business component tester shows?
Kind regards,
Markus

Andrejus' example shows how to calculate different values for the same attribute based on overridden view objects. That's not exactly what I'm looking for. I need to display a (at least partly) different set of attributes that changes while the user scrolls through the records of the result set.

How to create materialized view based on a view?

Hi,
I hope this is not very far fetched idea.
I have a very complex view and I would like to replicate it 'in place' that is I would like to make a materialized view that is based on this view complex view. I would like to use this materialized view (i.e table) to query data instead of using the original view, since it takes Oracle some 10-15 seconds to execute my query on the original view and I am not allowed to create indexes on most of the tables that are included in the original view.
Can this be done?
Best regards,
Tamas Szecsy

The best way to do this is to create a materialzed view based on the underlying code of the original view. If you don't have this handy, issue the following in sqlplus:
select text
from user_views
where view_name = 'NAME_OF_VIEW'
You can then cut and paste the sql statement into your create materialized view statement.
Please note, you will probable have to set the long parameter to a higher value to reveal the complete statement for example:
SQL> set long 2048

ADF BC: Creating updatable VO based upon DB View with "instead of" trigger

Hello all,
I have got an interesting issue. I have an Oracle DB view that is used to hide some complexity in the underlying DB design (it does some unions). This view is updatable because we have created an "instead of" update trigger to update the correct table when a row is updated. This is working fine in SQL.
Next, we have created an ADF Entity object based upon the view, specifying an appropriate PK for the DB View. Then, we have created an updatable VO based upon the EO. All well and good so far. The issue we have is in trying to commit changes to the DB - because the ADF BC framework is trying to lock the row to update (using SELECT ... FOR UPDATE), it's not working because of ORA-02014 - cannot select FOR UPDATE from view with DISTINCT, GROUP BY, etc.
This leads me to thinking about overridding doSelect() on the EO as hinted here http://radio.weblogs.com/0118231/stories/2005/07/28/differenceBetweenViewObjectSelectAndEntityDoselectMethod.html
As a temporary test, we have over-ridden the EO's doSelect to call super.doSelect(false) and it does work, although we will have lost update issues as detailed in Steve's article.
My questions:
1). Is overriding doSelect() the correct thing here? Perhaps there is a better way of handling this problem? I do have a base EO class from which all of the EO's extend, so adding this behavior should be straightforward.
2). Does anyone have example doSelect implementation? I am thinking of overriding doSelect for my EO and calling super.doSelect (lock=false), but then I need to deal with some possible exceptions, no?
Kind regards,
John

Hi John,
I have exactly the same issue as you experienced back in January. I have a complex data modelling requirement which requires the need to pivot rows into columns using ROW_NUMBER() and PARTITION clauses. To hide the complexity from the middle tier, I have created a database view and appropriate INSTEAD OF triggers and mapped my EO to the view. I have overriden the lock() method on the EO implementation class (to avoid ORA-02014) and would like to try the same solution you used with the pl/sql call to lock the record.
My question is, how did you manage the release of the lock if the transaction was not rolled back or committed by your application i.e. if the user closed the browser for instance.
In my naivity, I would like to think that the BC4J framework would release any locks for the database session when it found the servlet session to be terminated however my concern is that the lock would persist and cause complications.
Any assistance greatly appreciated (if you would be willing to supply your lock() method and pl/sql procedure logic I would be even more grateful!).
Many thanks,
Dave
London

How to create LOV not based on a View Object attribute?

Hi,
I am creating a handed-made search form and I want to create an af:inputListOfValues.
I have :
- a read-only-view-object to get the LOV values from BD.
- af:inputListOfValues tag (droped from Component Palette).
How can I create the listOfValuesModel in Bindings layer? (the inputListOfValues is not based on a View Object attribute).

Sorry, I think I am not very clear in my posts.
My requirement is to create a LOV but I have no ViewObject. I just want an input (not based on a view object attribute), alone, but with a LOV (where lov's datas are get from a view object).
In a "normal" LOV I would have something like this :
in jsff :
<af:inputListOfValues id="departmentIdId"
                            popupTitle="Search and Select: #{bindings.DepartmentId.hints.label}"
                            value="#{bindings.DepartmentId.inputValue}"
                            label="#{bindings.DepartmentId.hints.label}"
                            model="#{bindings.DepartmentId.listOfValuesModel}"
                            required="#{bindings.DepartmentId.hints.mandatory}"
                            columns="#{bindings.DepartmentId.hints.displayWidth}"
                            shortDesc="#{bindings.DepartmentId.hints.tooltip}">
        <f:validator binding="#{bindings.DepartmentId.validator}"/>
        <af:convertNumber groupingUsed="false"
                          pattern="#{bindings.DepartmentId.format}"/>
      </af:inputListOfValues>in pageDef :
<listOfValues StaticList="false" IterBinding="EmployeesView1Iterator"
                  Uses="LOV_DepartmentId" id="DepartmentId"/>in model layer : a view object (EmployeeView) with view accessor and LOV based attribute, and a read only view object (DepartmentRVO) to get datas for the LOV.
But in my case I have no ViewObject, so I don't know how to create the listOfValuesModel in fragment pageDef.
I have :
<af:inputListOfValues label="Label 1"
                                popupTitle="Search and Result Dialog"
                                id="ilov1" model="here I want to point to a listOfValuesModel but I don't know how to create it"/>in pageDef : the listOfValuesModel but I don't know how to create it.
in model layer : just a read only view object (like DepartmentRVO), to get the datas for the LOV.
Edited by: h0s on 29 févr. 2012 00:31

Can't create an app based on a view

I have a view based on more than one table and I tried to create a read-only application on this view, specifying Read Only for the create mode. It gives me a "no data found" error when I try to create the application. Can you not create an application on a view?

Karen - There's a bug when you create the app on a view in read-only mode. You'll have to stick with read-write mode for now.
Scott

Can I create a dimension based on a view?

The OLAP9201A allowes creating cube based on view, so does it also alowes creating dimension based on view?
I want to using view to deal with priviledge issues.

Thank you.
The document says that I can create view based dimensions using cwm2. But when I tried to execute cwm2 packages' procedures, I always got error.
For example, when I ran the following scripts under the schema 'CFA', I got error message.
--my scripts
begin
cwm2_olap_dimension.create_dimension('CFA', 'TESTCWM2_DIM', 'TESTCWM2', 'TESTCWM2s', 'cwm2', 'TESTCWM2',null);
end;
--error messages
The following error has occurred:
ORA-06502: PL/SQL: 数字或值错误 : 字符串缓冲区太小
ORA-06512: 在"OLAPSYS.CWM2_OLAP_MANAGER", line 380
ORA-06512: 在"OLAPSYS.CWM2_OLAP_MANAGER", line 397
ORA-06512: 在"OLAPSYS.CWM2_OLAP_DIMENSION", line 139
ORA-06512: 在line 2
--my comments on error messages
The Chinese text means:error of number or value: the string buffer is too small.
What's wrong?

View based form updation in 6i and 10g forms.

Hi All,
I am facing a strange problem.
I created a form based on a view, which is based on a single table. i made a copy of the form and converted it to 10g.
When running in 6i, i can update the data through forms. But in 10g, its showing FRM-40602: Cannot insert into or update data in a view.
Can anyone tell what is wrong?
Thanks & Regards,
Manu.

hi Manu
How to insert new record or update existing record using a complex view?
to make dml against a complex view with instead of triggers a reality. There should be no need to write an on-update trigger in your form. Indeed, the reason for a view and instead-of-trigger on that view is so that you do not require additional coding in your form.
1) you need the instead-of-trigger on the view (confirm it is there)
2) you need to change the locking mode in the form for the block based on your view so that it uses the logical key for locking purposes. There is a lock mode setting somewhere in the block properties page, find it, understand the differences and pick the righ tone (I forget at this moment which on it is, try them all if necessary).
3) #2 will involve selecting those fields that map to the business identifier/primary key you want to you use for finding rows. You need to visit each field's property page and set the appropriate attribute to indicate that is is part of the key used to find rows. It is there on the properties page but not having forms available at the moment I cannot give you the property name. You will have to do a little exploring to find it.
If you do these things, the error should go away and the view become updatable via oracle forms without the need to write any on-update trigger.
Do some testing at the database level first. Make sure you can update the view directly via sqlplus first with the instead-of-trigger before you attempt it in the form. This will ensure that your issue is forms related and not database related. This is an important step because the database will return a similar error to what you have reported if the instead-of-trigger does not exist on the view.
sarah

Using geocode in a map based on a view where two datasets are joined

Hi,
I'd like to create a map based on a view in which two datasets are joined, where one of the datasets has a geocode column.
Unfortunately this is not working... It seems that a custom view where two datasets are joined together where one of them has a geocode column makes the geocode column invisible for the map component.
The following cases do work but we like to combine them so that we can combine different datasets in Studio without using the Integrator:
- I can create a custom view in which we join two datasets > the view can be used as a source for different component but not the map component (it seems that the geocode column is not found)
- I can create a custom view with a geocode column in it and that one can be used as a source for a map
What I'd like to show is that it is possbile to have one datasets coming from a source system and that it is easy to combine an additional excel sheet with geo-information and maybe another excel sheet with different measures. This should be possible since you can join different datasets together in a custom view.
Thanks in advance,
Richard

Oh sorry, we have two base views and one custom view:
base view TRIS_Omzet which gets it data from an OBI server and has data like revenue, customer, time, etc.
base view Endeca_Klanten which gets it data from an excel sheet, this view contains the name of the customer and the geocode of the customer's location
We created one custom view (Omzet_Geo) where the two base queries are joined together using the following query:
DEFINE V1 AS SELECT
"Endeca_Klanten.Klanten" AS Klant,
"Endeca_Klanten.Coordinaten" AS Coordinaten
from Endeca_Klanten;
DEFINE V2 AS SELECT
"TRIS_Omzet.Naam_Consultant" AS Naam_consultant,
"TRIS_Omzet.Jaar" AS Jaar,
"TRIS_Omzet.Jaar_week" AS Jaar_week,
"TRIS_Omzet.Actual" AS Actual,
"TRIS_Omzet.Omzet" AS Omzet,
"TRIS_Omzet.Partij" AS Partij,
"TRIS_Omzet.Uren" AS Uren
FROM TRIS_Omzet
DEFINE Omzet_Geo AS SELECT
V1.Klant AS Klant,
V1.Coordinaten AS Coordinaten,
V2.Naam_consultant AS Naam_consultant,
V2.Jaar AS Jaar,
V2.Jaar_week AS Jaar_week,
sum(V2.Actual) AS Actual,
sum(V2.Omzet) AS Omzet,
V2.Partij AS Partij,
sum(V2.Uren) AS Uren
from V1
right join V2
on (V1.Klant=V2.Partij)
group by Klant, Coordinaten, Naam_consultant,Jaar,Jaar_week,Partij
Our view definition in the GUI looks like the following, as shown in the screenshots the datatype of the coordinated column is a Geo column both in the base view and the custom view. However the view still can't be selected to be used as a source for the map component.
The two base views:
The custom view:
regards,
Richard

Block based on a view

We have a block which is based on a view. When using Forms 6i 6.0.8.8.0 (no patch), querying from this block cause no problem. However, after applying patch 1 (6.0.8.10.3), the form crashes or take forever to retrieve the data.
Anyone has run into this problem ?
Is there a work-around other than installing a full patch ?
Is this a known bug ?
Thank you.

you create the view based on the tables first, then you use form design wizrad to create the form based on the view like a table.
If you want to allow user to edit the fields, then you may either to create a INSTEAD OF trigger on that view in database, or in form block, using ON-LOCK, ON-UPDATE/INSERT/DELETE triggers to do it.

How to create a view based on Lookup Column?

Hi All,
I am working as a SharePoint developer 2013.
When i tried to create a view based on look up column it is not showing lookup column.
How to fix this problem?
Please help me out here.
Thanks & Regards,
Santhoshi

can you elaborate the issue? Do you mean you cannot view the column name in the filter section when creating a new view for the list or the column is not getting displayed in the view created?
--Cheers

How to create materialized view based on a synonym

Hi all,
I am trying to create simple materialized view based on a synonym and that synonym is pointing a view in other database (using dblink). I am getting table or view not found error . I am able to select synonym if i use select but not in materialized view. Please help me.
Thanks,

The best way to do this is to create a materialzed view based on the underlying code of the original view. If you don't have this handy, issue the following in sqlplus:
select text
from user_views
where view_name = 'NAME_OF_VIEW'
You can then cut and paste the sql statement into your create materialized view statement.
Please note, you will probable have to set the long parameter to a higher value to reveal the complete statement for example:
SQL> set long 2048

List View Filter - I want to create List View based on a specific user

I want to create a List View Filter based on specified user ID. I dont want to specify the [Me] for filtering the view based in current logged in User.
I want the view to be based on specific user ID for Ex: "AD\JohnDoe"
Thanks
Nate

The People/Group Picker field has several options for how the name is displayed. For example you can set it to be the friendly name or the account name. When you create your View Filter, make sure that you are using the same format as the field's display
type.
Dimitri Ayrapetov (MCSE: SharePoint)

Create a view based off a query in Access WebApp

I'm trying to create a summary view based on a query. The query is being used to make a simple join two tables. I don't have an issue creating a datasheet or list view off the query, but when I try to create a summary view, I'm unable to
create it.
From the desktop app, I'm able to click on the plus sign to add a new view, give it a name, choose the type and select my record source. When I click on "Add New View" nothing happens. I do not get any progress dialog box as I do for
other views. The popup for the "Add New View" simply disappears. Is this the expected behavior?
Based on this thread I don't think so.
https://social.msdn.microsoft.com/Forums/en-US/a5e60abc-0061-429e-8ce8-2014626c42c2/access-web-app-open-a-subform-from-a-query-based-summary-view?forum=accessdev
Again, this is a simple query table 1 has 8 colums, all of them are simple text except for one lookup column that includes the data with the table, one column stores the a primary key from the second table. The second table is a simple table with
3 columns.
Is this a limitation of the Access Web App?

Hi,
You should be able to create a new summary view off a saved query. The behavior you describe sounds very odd but I’m not able to repro this on my computer. Could
you try something for me? Try and create a new summary view and use a table as its record source. Does that get created OK?
Jeff Conrad - Access Junkie - MVP Alumnus
Senior Content Developer - Modern Assistance and Support Experience - Microsoft Corporation
Author - Microsoft Access 2013 Inside Out
Author - Microsoft Access 2010 Inside Out
Co-author - Microsoft Office Access 2007 Inside Out
Access 2007/2010/2013 Info: http://www.AccessJunkie.com
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Creating View based on Current and previous data from same table

I am trying to create a view based on a table called “my_companies”. The table has following columns: “company_id”, “start_date”, “product_type_code”, “partner_id”
The main purpose of this view is to obtain previous company_id’s associated with a particular “partner_id“and “product_type_code”. So basically, I’m looking to create an extra column, say “prev_company_id” in the view along with all the other columns. The “previous” data can be obtained depending on the “start_date”. I’m not able to write a query successfully to do this.
Can anyone help? Thanks in advance.

Hi,
Whenver you have a question, it helps to post:
(1) The version of Oracle (and any other relevant software) you're using
(2) A little sample data (just enough to show what the problem is) from all the relevant tables
(3) The results you want from that data
(4) Your best attempt so far
Executable SQL statements (like "CREATE TABLE AS ..." or "INSERT ..." statements) are best for (2).
Formatted tabular output is okay for (3). Type before and after the tabular text, to preserve spacing. The sample results should include any special cases that you foresee, such as one company having many previous companies, or vice-versa.
It sounds like might need a +self-join+, where you have two copies of the same table, as if the current companies were in one table and the previous companies were in another, even though they are all actually in the same table.

Create a view based on a view

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