I would like to specify in Oracle REST query which columns should be returned in the select statement.
One of the solution would be to use view, however in my case I would like to select columns in a dynamic fashion.
Such functionality is available in PostgREST: http://postgrest.org/en/v6.0/api.html#vertical-filtering-columns
Is there such feature in Oracle REST Data Services?
No, we offer row filtering but not column selection.
So i can say which rows I want to come back via the URI, but I cannot say which columns I want.
So if you REST enable a table or view, it will be all of those columns, of it it's a RESTful Service, it will be the columns you have included in your SELECT.
Something else to keep in mind, we do have a REST Enabled SQL Feature...where you POST your query, and we get you the results. So in the POST you could specify the columns you want.
Related
TLDR; is there a way to understand at runtime which format is ADF using for dates behind the scenes? In particular the format used to render dates in dynamically generated sql code?
In the Oracle ADF Application I'm working on there are several table filters (by that I mean the field over the column in which I can write text/number/dates to query the table).
Filtering this way, the framework modifies the query of the View Object, adding the appropriate where clause. On the page there's also a button "Select all" that allows me to select all the data that's rendered in the table (there is a selection checkbox).
In the specific case, the query from the VO is used to aim two different goals:
update the rendered data in the table
if I press the "select all" button a function in the backend database is called (callable statement calling the function), passing as a parameter the query.
The first task is successfully reached (as the table is visually updated), but we had an issue with the second one.
The backend function uses the query to select all the extracted data (as iterating in ADF with java would be too slow).
The problem is that the where clause isn't correctly generated for the backend database (which is also oracle).
Basically the generated WHERE clause (which was added to VO's query automatically by the framework) was
WHERE record_date = '2020-10-12'
which I had to change to
WHERE record_date = to_date('2020-10-12', 'YYYY-MM-DD')
in order to have it correctly executed by the Oracle Db.
So now it's working (yay), but my concern is: isn't it dangerous to assume the date format will be 'YYYY-MM-DD' on every application's instance?
I think this 'YYYY-MM-DD' is the format in which ADF is managing dates (as the value is written as '2020-10-12' in the query).
But is there a way to understand at runtime which format is ADF using for dates behind the scenes? Or does it always use 'YYYY-MM-DD', or am I completely off-road and the storage format is another and I should ask which format does it use to render dates? But dates on page are visually rendered in another way :/
Sorry for my lack of expertise and have a nice day!
Update
The value of the query field, which I'm getting by calling
this.getNamedWhereClauseParams().getAttribute('vc_temp_1');
is of class
oracle.jbo.domain.Date
and by printing it I obtain the date in format YYYY-MM-DD.
Would it be possible that the framework was simply using Date.toString?
This would raise another question: how can I be sure of the pattern used by Date.toString? The documentation isn't clear about it (and it says that it should be used only in development, so this is quite a remote scenario).
What you named 'Filter' is called 'Query by Example' or QBE in short. See the doc for more info.
You can change the query passed to the server using a bean method. Look at e.g. JDev 12.2.1.3: Multi select component table filter for a sample.
Using dates in ADF is always dependent on the current user's settings. If the user don'T use a specific locale the default is 'yyyy-mm-dd'. This can be changed at different points, starting by the entity objects, view objects a,d finally in the UI by using converters.
The best way to use dates depends on the use case.
I have a database table on which a sorted query needs to be done.
To do the sorting a join on another table is requiered. The problem is that this other table does not exist in the database because we read the required data on the services startup from a CSV file and keep it as an in-memory list.
Is it possible to somehow inject this list as a kind of virtual database into Spring Data? So that it could use this list to make the required join and sorting.
As far as I know, the only other options I have would be to create a real database table from this in-memory list or load the whole table and do the sorting in the service itself.
You can add a special order by expression through e.g. Spring Data Specification, but that is going to be very ugly. In HQL it looks like this:
case rootAlias.attribute when 'value1' then 1 when 'value2' then 2 ... else null end
which will return some integer value by which you can sort ascending or descending, based on the mapping you have.
Even if you have lots of values, I would rather recommend you don't do a join at all, and instead try to make this attribute of your main table sortable, so that you don't need this mapping. You can maybe create a trigger that maintains a column based on the mapping, which can be used for sorting directly. If you do all your changes through JPA/Hibernate, you could also use a #PreUpdate/#PrePersist listener to handle the maintenance of this column.
I am using Dynamics AX 2012 R2.
I am creating a query for a view where I have to filter out data based on predefined business logic.
For example, I have one table in my query (simplified) and I want to be able to filter out rows in the view where the sum of value1 and value2 and value3 are equal to zero.
I cannot use the query range in the query since I have around 20 values (columns) that I need to check before I filter out the rows. It doesn´t allow it, it only handles around 10 values or so
I dont like creating a "full" view, e.g. view with all rows then a view method with the business logic that has to be applied to filter out the rows and then a query based on that view where the rows are filter out.
Do you have any ideas?
Why not make a computed view field for the sum of your fields?
I dont like creating a "full" view, e.g. view with all rows then a
view method with the business logic that has to be applied to filter
out the rows and then a query based on that view where the rows are
filter out.
You are cutting out a useful method (but you need not make any queries).
Another approach would be to make a redundant field in your base table with your 20 fields added.
Update: Please read View Basics.
I'm am getting irritated with iReports. Problem is that I have a data set returning data for multiple customers and I want to use the "Group Expression" against the customer ID and have the report lay out the Detail Tabs per customer.
I'm finding that, seeming randomly, where there is more that one data row for a customer iReports will generate two or more groupings (Sometimes it does what I expect and group all the customer data together), the field IDing the customer is the same and doesn't change.
Has anyone seen this before? To be honest I can't believe it is actually a bug, but something I've missed. Just much searching as yet to find a suitable result.
I think this is a data sorting problem.
The quote from iReport Ultimate Guide:
JasperReports groups records by evaluating the group expression. Every
time the expression's value changes, a new group instance is created.
The engine does not perform any record sorting (if not explicitly
requested), so when we define groups we should always take care of the
records sorting. That is, if we want to group a set of addresses by
country, the records we select for the report should already by
ordered by country. It is simple to sort data when using an SQL query
by using the ORDER BY clause. When this is not possible (that is, when
obtaining the records from an XML document), we can request that
JasperReports sort the data for us. This can be done using the sort
options available in the query window
You can sort data in these ways:
in case using of Database jdbc connection datasource type you can add ORDER BY customerId clause to the report's query, where customerId - column name of field with customer id
in case using of File csv connection or something like this you can organize data sorting by adding sortField property for field to the report's template (jrxml file):
<jasperReport ...>
...
<field name="customerId" class="java.lang.String"/>
<sortField name="customerId"/>
SQL Statement has ORDER BY?
iReport group is grouped by customer_id?
I am using jqgrid, with filter toolbar(column) option...The total data is around 10,000...So it seems to be some delay in initial loading as the config is set to loadonce:true;
Any way to implement the filter column feature with loadonce:false ?
Because the data loading delay is okay with loadonce:false. If I get a chance to add column filter with loadonce:false, this will work perfectly...
If you has about 10,000 rows it is of course better to implement server side data paging, sorting and filtering. I recommend you to use filterToolbar with the parameter stringResult:true if you not already use it. In the case jqGrid will send to the server filters parameter in the same format like advanced searching as do. So you will need implement on the server side the method which use following input parameter from jqGrid:
sidx and sord parameters define the sort order of the data. The informations specify ORDER BY in the corresponding SELECT statement.
if _search parameter is true, then the next parameter filters gives additional information which construct the WHERE part of the corresponding SELECT statement.
page and rows parameters define which page of the data previously sorted and filtered should be returned.
The exact implementation is depend on the language and technology which you use on the server and of course which database server and which interface to the database you use.