topic Re: Using Class Method in a Select Where Clause in Application Development and Automation Discussions

Using Class Method in a Select Where Clause

Former Member — Thu, 02 Oct 2014 06:45:43 GMT

Hi All,

I have noted something that can be done when processing internal tables but doesn't seem to work for Select statements against a DB table.

So, lets say I have class ZCL_MyClass which has a static method GET_RANGE.

The static method returns a Range.

If I have an internal (lt_tab) I can do the following:

delete lt_tab where statu in ZCL_MyClass=>GET_RANGE( ).

Is it possible to do something similar when using SQL. for example something like:

select *
into table lt_tab

from mara
where statu in ZCL_MyClass=>GET_RANGE( ).

I have a number of ways I would also like to use this scenario (basically using the class method like a function is used in other languages) but this scenario is specifically what I am interested in at the moment.

I was also wondering whether (if the scenario is possible) whether a singleton would be a good idea in this case?

I have searched the forums but nothing similar seemes to come up.

Look forward to hearing the replies

Many thanks

Gaz Hawkins

Re: Using Class Method in a Select Where Clause

Former Member — Thu, 02 Oct 2014 11:15:28 GMT


select *
   into table lt_tab  
   from mara
   where  statu in  ZCL_MyClass=>GET_RANGE( ).

SQL conditions seem to have a more restrictive syntax. How about trying the following:

data(rt_statu) = ZCL_MyClass=>GET_RANGE( ).

select *
into table lt_tab

from mara
where statu in rt_statu.

Re: Using Class Method in a Select Where Clause

Former Member — Thu, 02 Oct 2014 11:49:50 GMT

Hi Eric,

That is certainly would be neater than declaring the range and doing a method call.

Unfortunately that doesnt compile.

Although that is another point that would be nice to know.. can we can shortcut method calls in other ways.. for example in an IF statement.

if lv_myvar = zcl_myclass=>get_var( ).

"Do stuff

EndIf.

if lv_myvar = zcl_myclass=>get_var(exporting it_check = lv_check).

"Do stuff

EndIf.

Having used OO in other programming languages and being able to do similar the above using functions it would be useful to use it in ABAP.

Thanks for the reply

Gaz Hawkins

Re: Using Class Method in a Select Where Clause

Former Member — Thu, 02 Oct 2014 12:41:13 GMT

Something like:

if lv_flag eq return_bool( ).
clear sy-subrc.
endif.

But it only works in ABAP release 7.4.

Re: Using Class Method in a Select Where Clause

RaymondGiuseppi — Thu, 02 Oct 2014 12:53:08 GMT

IF does not (yet) allow this, but CASE/WHEN allows it :


operand, operand1, operand2, ... are enhanced functional operand positions alongside which all functional methods and all predefined functions which have exactly one unnamed argument can be specified.

Regards,

Raymond

Re: Using Class Method in a Select Where Clause

Former Member — Thu, 02 Oct 2014 14:32:05 GMT

Thanks Eric and Raymond,

Your answers prompted my to try this out and for IF (and CASE by the sound of it) you can use a methods RETURNING parameter to acheive this.

if we have a class:

class lcl_test definition.
   PUBLIC SECTION.
   CLASS-METHODS: get_value importing iv_num type i
                                               RETURNING value(EV_NUMBER) type i.

endclass.

class lcl_test IMPLEMENTATION.
      METHOD GET_VALUE.
             ev_number = 2.
       ENDMETHOD.
endclass.

We can then use this in an IF statement like:

data:lv_ret type i.
lv_ret = 1.

if lv_ret = lcl_test=>get_value( iv_num = 1 ). "this would not match as method returns 2
"matched....
endif.

So, I can do what I want to do in general code but SQL statements seem to be a different beast.

Anyone acheived anything similar in SQL?

Thanks Again for the replies

Gaz Hawkins

Re: Using Class Method in a Select Where Clause

VenkatRamesh_V — Thu, 02 Oct 2014 16:26:29 GMT

Hi Gray,

Try with field symbols.

Regards,

Venkat.