is it possible to add a dynamic value on filter.
I'm trying to save a report with a filter using the current user:
A solution to this problem is to include the variable as a column in your query and then filter on that column.
Example:
Your select would be something like
SELECT
your_value1,
CASE WHEN created_by = :APP_USER THEN 1 ELSE 0 END AS is_current_user
FROM
your_table
If you then set a filter on is_current_user you'll only get the rows where created_by = :APP_USER.
Maybe it is possible; though, I don't know how. Whichever option I tried:
:APP_USER
&APP_USER.
v('APP_USER')
created a page item whose source is :APP_USER and base filter on that item
nothing worked. Apex applies single quotes around those expressions and - therefore - treats them as strings, e.g. ':APP_USER'.
However, what you might do in this particular case is to edit the query itself and add WHERE condition:
where blocked_by = :APP_USER
That would certainly work.
Related
I do voluntary work at an animal shelter. We have an application which uses a SQL Server 2019 database. I have created a view that includes a varbinary(max) column. The value in this column is a picture, stored in hexadecimal-format. I would like to convert this Hex-value to a base64-binary file and add these to the view as an extra column.
I found the perfect solution for my situation in SQL Server : hex to base64. The example provided converts 1 single hex-value into 1 base64-value. I now need to add this solution to my view, but I'm not having any success.
The offered solution:
DECLARE #TestBinHex varchar(max), #TestBinary varbinary(max), #Statement nvarchar(max);
SELECT #TestBinHex = '0x012345';
SELECT #Statement = N'SELECT #binaryResult = ' + #TestBinHex;
EXECUTE sp_executesql #Statement, N'#binaryResult varbinary(max) OUTPUT', #binaryResult=#TestBinary OUTPUT;
SELECT
CAST(N'' AS XML).value(
'xs:base64Binary(xs:hexBinary(sql:column("bin")))'
, 'VARCHAR(MAX)'
) Base64Encoding
FROM
(SELECT #TestBinary AS bin) AS bin_sql_server_temp;
A simplified version of my view:
SELECT
a.cat_id, a.catname, s.cat_id,
s.stay_id, s.shelter_handler, s.shelter_kennel, s.picture
FROM
dbo.animal AS a
OUTER APPLY
(SELECT TOP 1 *
FROM dbo.shelterdata
WHERE a.cat_id = s.cat_id
ORDER BY s.stay_id DESC) AS S
WHERE
(a.cat_id IS NOT NULL) AND (s.leave_date IS NULL)
The view shows an overview of all cats currently present in the shelter (leave_date is NULL). The reason for the TOP 1 is that sometimes shelter animals get returned, and the application then assigns a new stay_id. To prevent duplicate values from the join, I only return the value of the most recent stay_id.
What I am trying to achieve: the second table (dbo.shelterdata) includes the picture, stored in hex value. I'd like to add a column Base64Encoding to the view which includes the converted value.
My attempts
I was successful in replacing the static value '0x012345' by a SELECT statement. But the way the solution is formatted, it only allows for one input value. So I had to restrict it with a WHERE clause. It is obvious to me that I need to make a subquery which inputs the hex value based on the unique cat_id. However, it has been many years since I worked with variable, so I'm struggling with the formatting of the statement.
My request
Does anyone have a suggestion how to build the conversion into the view?
Any assistance would be greatly appreciated.
After searching for a few more hours, I stumbled onto the solution. Maybe it will help someone else in the future. The solution is remarkably simple, as is often the case.
My view, mentioned above, is called dbo.shelter_view
select sv.picture,sv.cat_id,
cast('' as xml).value(
'xs:base64Binary(sql:column("sv.picture"))', 'varchar(max)'
) as Base64Encoding
from dbo.shelter_view as SV
We have front-end app where user enters customer and/or PO to retrieve data.
For instance, if user want to retrieve all POs for a customer, he will enter '%' in PO field.
If user wants to retrieve all data, he will enter '%' in every field.
I am trying this, but it does not work
SELECT *
FROM PO_INFO
WHERE customer_id = case when '%' then customer_id else 'Macys' end
AND purchase_order = case when '%' then purchase_order else '79124' end
What am I missing?
You should not (some would say must not) just plug the user-entered search values into your SQL query as literals. That is,
AND purchase_order = case when '%' then purchase_order else '79124' end
... is not going to perform or scale well because every single search looks to Oracle like a brand new SQL query that has to get parsed and optimized (i.e., "hard parsed). This is an expensive process that also requires a lot of latches, meaning multiple users trying to run searches at the same time will have to wait for each other.
Instead, you should construct your SQL using bind variables. So,
AND purchase_order = :1 -- or something. We'll discuss the exact logic later...
That :1 is a bind variable, a placeholder for a value your code will supply when it submits the query. Now, everyone doing a search is using the same query (just each supplying different values for the bind variables). No more excessive hard parsing and performance disaster averted.
But, here is the next problem. One query for all means it only gets hard parse one time (good) but it also means everyone runs using the same execution plan. But in a search like this, one size does not fit all. Suppose the execution plan Oracle comes up with uses an index on column 'ABC'. If a user does not supply a bind variable value for column 'ABC', that execution plan will still be followed, but with terrible results.
So, what we want really is one SQL for each set of bind variables that have values or don't, but not one SQL for each distinct set of literal search values.
Build your SQL in code by starting with this string:
SELECT * FROM PO_INFO WHERE 1=1
Then, for each search condition add this (if the value is %)
AND (:1 IS NULL) -- and pass `NULL`, not "%" as the value for :1
(Aside: the reason for this condition, which is essentially NULL IS NULL is to make to so the number and order of the bind variables that have to be passed in is always the same, regardless of what the end user does or does not give you a value for. This makes it much easier to submit the SQL in some languages, like PL/SQL).
If the search condition is not %, add this:
AND (customer_id /* or whatever column */ = :1) -- and pass the user-entered value
So, for example, if the user specified values for customer_id and po_date but not purchase_order, your final SQL might look like:
SELECT *
FROM PO_INFO
WHERE 1=1
AND customer_id = :1
AND po_date := 2
AND :3 IS NULL -- this is purchase order and :3 you will pass as null
If you do all this, you'll get the least amount of hard-parsing and the best execution plan for each search.
I am writing queries for reports using Eclipse/BIRT. At the moment I create a query with ? characters for parameters, and I can then assign values to the parameters under the parameter tab.
However, if I need to assign the same value multiple times, I have to do this multiple times, once for each appropriate ?. Additionally, this system is fragile - if I add a question mark in the middle of the query, I need to adjust and reorder the list of parameters.
Is there a way to use named parameters rather than question marks in the original query?
BIRT query doesn't support named parameters but if database supports WITH statement, you can do what is illustrated here:
http://enterprisesmartapps.wordpress.com/2011/01/10/re-using-parameters-in-birt-data-set/
Basically, you're query becomes:
WITH
params AS
(SELECT ? AS year FROM dual)
SELECT * FROM tab1, params WHERE year = params.year
UNION
SELECT * FROM tab2, params WHERE year = params.year
Then you can set the ? once.
How to set a conditional DEFAULT value to a column in oracle without using triggers?
I want to achieve following needs:
If "flag1"=1 then Default value to column Newfield must be "4".
If "flag1"=2 then Default value to column Newfield must be "5".
That's what triggers are for. Use them.
A column DEFAULT is not allowed to reference another column, so this is not possible.
You could perhaps just let the default remain as NULL, and then have a view to adjust it like:
create view mytable_view as
select flag1, nvl(newfield, case flag1 when 1 then 4
when 2 then 5
end) as newfield
from mytable;
If column Newfield does not need to be updateable, then you could simply implement it in a view, as Tony showed, or in 11g you could make it a virtual column.
If 'flag' is something session (or statement) level then SYS_CONTEXT may be a way through. Possibly a BEFORE STATEMENT trigger if the issue is avoiding a context switch for every row inserted
<-------PeopleCode------>
Hi,
I have a SQL query that i have tried executing using both SQLEXEC and SQL.fetch() but the problem is, when I am passing the values to parameters (:1,:2...) it does not return a row but when I hardcode the values in the where clause of the query itself, it retrieves the correct value.
Can anybody help?
My query looks similar to the following sample query :
Select * from PS_rec1 where emplid=:1 and plan_type=:2
it returns no data till i hardcode the values.
I have checked the values at the back end and some data is there to be fetched. Moreover, the same query retrieves data when ran in TOAD.
Have you tried outputting your binds to a log file just before you use them in your SQL statement?
If the binds aren't working, but literals are, then perhaps your binds don't contain the values that you expect them to.
You could also try explicitly setting the binds to the values that you're expecting just before the SQL statement. This will prove that the way you're passing in the binds is working correctly.
It required another update to the same record to get the values fetched in SQL exec.
M not sure what was the problem but i guess it might be that the previous update did not write the changes to the db even after an explicit commit.
Ok, you need to put your exact SQLExec statement in the question.
But, do you really have "Select * ..." in a SQLExec? How many columns are in your table? Since you mention the where clause, is your statement
SQLExec("select * from PS_rec where emplid=:1 and plan_type=:2", &var1, &var2, &vartocontainthewholerow);
Which will work in a SQL tool (toad) but probably does not work in AE or any type of Peoplecode program.
Now if your table has three columns, should you not have something like this:
SQLExec("select emplid, plan_type, column3 from PS_rec where emplid = :1 and plan_type=:2", &emplidIn, &plan_typeIn, &emplidOut, &plan_typeOut, &column3Out);
Notice that with three columns in the table that emplid and plan_type are two of them, you need to list all the columns you want, not asterisks '*'. Kind of silly to select the emplid and plan_type though.