Getting table structure of itab fails - abap

I'm currently working on a project to extract data into several itabs and save them all into a single excel file on my local pc.
For moving my data into the excel file, I have to loop over the fields of the tabel which seems to be archivable with the cl_abap_structdescr=>describe_by_data and cl_abap_tabledescr=>create function. In the original article I read, the author used them with a ABAP Dictionary table, my goal is to use it with arbitrary internal tables.
I tried it within a test report and used T005 for the test:
data:
lt_t005 type standard table of t005,
ls_t005 like line of lt_t005,
tablestructure type ref to cl_abap_structdescr,
tabletype type ref to cl_abap_tabledescr.
*tablestructure ?= cl_abap_structdescr=>describe_by_name( 'lt_t005' ).
tablestructure ?= cl_abap_structdescr=>describe_by_data( lt_t005 ).
tabletype ?= cl_abap_tabledescr=>create( p_line_type = tablestructure ).
Neither of both describe_by_name() nor describe_by_data() work, describing by name results in a "NOT_FOUND" exception. Since it is no ABAP Dictionary Table this kinda makes sense to me. Describing by data results in a CX_SY_MOVE_CAST_ERROR telling me that the source type \CLASS=CL_ABAP_TABLEDESC cannot be converted into "\CLASS=CL_ABAP_STRUCTDESC.
Thanks in advance

Use this variant:
tablestructure ?= cl_abap_structdescr=>describe_by_data( ls_t005 ).
tabletype ?= cl_abap_tabledescr=>create( p_line_type = tablestructure ).
DATA table TYPE REF TO data.
FIELD-SYMBOLS: <tab> TYPE ANY TABLE.
CREATE DATA table TYPE HANDLE tabletype.
ASSIGN table->* TO <tab>.
SELECT *
FROM t005
INTO TABLE <tab>.
Pay attention to the first line which is different from yours, describe_by_data method accepts flat structure, not an itab.
Here is a good overview of all RTTS objects and their methods available.

You are trying to create a table description using the class cl_abap_structdescr. Which doesn't work, because that class is for structures, not for tables.
When you want a table description, use the class cl_abap_tabledescr.
tabletype ?= cl_abap_tabledescr=>describe_by_data( lt_t005 ).
When you also need the structure description for a line of said table, you can obtain that through the table description:
tablestructure ?= tabletype->get_table_line_type( ).
Note that the last line will throw a CX_SY_MOVE_CAST_ERROR exception if the internal table has a line type which is not a structure (like a TYPE TABLE OF string).

Related

Pass inline declared table/variable to subroutine in ABAP

I know when I need to pass an internal table to a subroutine, I need to declare a type so I can use it in the FORM statement.
What happens if the internal table is an inline declaration table from a SELECT statement like this:
SELECT * FROM KNA1 INTO TABLE #DATA(LT_KNA1)
Is there any way to pass this table to a subroutine?
Thank you.
The subroutines are obsolete since ABAP 7.02 (2009), so I use a method in my example.
Inline declarations are an easy way of declaring types implicitly, but the limit of this solution is that you can type the parameter of a method only generically (types STANDARD TABLE, INDEX TABLE, ANY TABLE, ANY) which prevents you from stating the component names statically in your code.
But inline declarations of type DATA(...) are always based on a complete "bound" data type, so you can declare the type explicitly with TYPES and use it to type both your parameter and your data object.
If you use the ABAP Development Tools (Eclipse), you may use the Quick Fix "Declare local variable ... explicitly" to simplify the task:
which gives this code:
REPORT.
CLASS lcl_app DEFINITION.
PUBLIC SECTION.
CLASS-METHODS main.
ENDCLASS.
CLASS lcl_app IMPLEMENTATION.
METHOD main.
TYPES: BEGIN OF helper_type, " <=== automatically generated
carrid TYPE scarr-carrid,
carrname TYPE scarr-carrname,
END OF helper_type.
DATA: lt_scarr TYPE STANDARD TABLE OF helper_type. " <=== automatically generated
SELECT carrid, carrname FROM scarr
INTO TABLE #lt_scarr. " <=== automatically changed
ENDMETHOD.
ENDCLASS.
Now, declare manually the table type, use it to type a parameter of a method (a new one here):
REPORT.
CLASS lcl_app DEFINITION.
PUBLIC SECTION.
TYPES: BEGIN OF helper_type,
carrid TYPE scarr-carrid,
carrname TYPE scarr-carrname,
END OF helper_type.
TYPES: tt_scarr TYPE STANDARD TABLE OF helper_type. " <=== declare the type
CLASS-METHODS main.
CLASS-METHODS process_table " <=== new method with this type
IMPORTING table TYPE tt_scarr.
ENDCLASS.
CLASS lcl_app IMPLEMENTATION.
METHOD main.
DATA: lt_scarr TYPE STANDARD TABLE OF helper_type.
SELECT carrid, carrname FROM scarr
INTO TABLE #lt_scarr.
ENDMETHOD.
METHOD process_table. " <=== new method
LOOP AT table REFERENCE INTO DATA(line).
DATA(carrid) = line->carrid.
ENDLOOP.
ENDMETHOD.
ENDCLASS.
Use TYPE ANY or generic table type for parameters, TABLE parameters are obsolete:
FORM fill_table USING tab TYPE any
CHANGING ptab TYPE INDEX TABLE.
APPEND LINES OF tab TO ptab.
ENDFORM.
And yes, subroutines are obsolete themselves, use them only if you absolutely must do this, e.g. in legacy environment.
You don't need to indicate structure type for perform variable table. But you can get error on runtime if any field name change which are used in perform. Two working example below.
SELECT * FROM kna1 INTO TABLE #DATA(lt_kna1).
PERFORM test TABLES lt_kna1.
FORM test TABLES pt_kna1 STRUCTURE kna1.
*
ENDFORM.
Risky one:
FORM test TABLES pt_kna1.
*
ENDFORM.

Convert dynamic REF TO DATA structure to static

I created structure with three components, one of which is type ref to data and a table type of this structure. The problem is, how do I add data to this table?
It always has three components, but only one of them is discovered during processing, I always know two of them. Thus I always use the entire table type ref to data and then determine the type of this structure and create the table on it.
The issue here is that by doing this, even though I know two of the components, the whole itab will be dynamic, so I must use it in methods exporting/importing a type ref to data, which is inconvenient.
The method below will always return a table type ref to data, which is completely dynamic (type ref to data), but the structure of the table will always be like this:
component 1 -> type pc261.
component 2 -> type pay99_international.
compoment 3 -> well this is always a mistery hehe
methods get_payroll
importing it_rgdir type hrpy_tt_rgdir
returning value(rt_value) type ref to data.
method get_payroll.
field-symbols: <lt_payroll> type standard table.
create data rt_value type standard table of (mv_py_struct_type).
assign rt_value->* to <lt_payroll>.
...
endmethod.
My intention was to have the returning value with another type, a known type, with which I can use the two known components more easily. The idea I had was to create a type with only the unknown field as ref to data, than have a table of it.
This way, I would be able to use it inside methods without having to work so "dynamicaly", which altough works perfectly, is kind of difficult to understand only by reading the code.
types begin of gty_s_generic_payroll.
types evp type pc261.
types inter type pay99_international.
types nat type ref to data.
types end of gty_s_generic_payroll.
types gty_t_generic_payroll type table of gty_s_generic_payroll.
The problem is, how to use an itab of type gty_t_generic_payroll as declared above?
I must somehow create the component 3, but I have no idea how to do it...
At the end, I have a generic field-symbol, that is type table, that has the two known components + the third one that was discovered during processing time.
So how can I pass the content of this field symbol to a table type gty_t_generic_payroll?
data lt_payroll type ref to data.
field-symbols <lt_payroll> type any table.
lt_payroll = mo_payroll->get_payroll( lt_rgdir ). "this will return type ref to data
assign lt_payroll->* to <lt_payroll>.
After executing this code <lt_payroll> has all the values, but it is a dynamic table where I cannot use components <lt_payroll>[1]-inter.
So how to pass to gty_t_generic_payroll-typed variable, so that I can access components without much dynamics?
Given your target structure and table like this:
TYPES:
BEGIN OF payroll_row_type,
known_first_component TYPE something_we_know,
known_second_component TYPE something_else_we_know,
discovered_component TYPE REF TO data,
END OF payroll_row_type.
TYPES payroll_table_type TYPE STANDARD TABLE OF payroll_row WITH EMPTY KEY.
If you now have another table, whose type at runtime is:
TYPES:
BEGIN OF discovered_row_type,
known_first_component TYPE something_we_know,
known_second_component TYPE something_else_we_know,
known_third_component TYPE some_data_type,
END OF discovered_row_type.
TYPES discovered_table_type TYPE STANDARD TABLE OF discovered_row WITH EMPTY KEY.
You can move one to the other with
DATA source TYPE discovered_table_type.
DATA target TYPE payroll_table_type.
DATA resolved_component TYPE REF TO DATA.
DATA(descriptor) =
cl_abap_elemdescr=>describe_by_data( source_row-known_third_component ).
LOOP AT source INTO DATA(source_row).
DATA(target_row) =
VALUE payroll_row_type(
known_first_component = source_row-known_first_component
known_second_component = source_row-known_second_component ).
CREATE DATA target_row-discovered_component TYPE descriptor.
ASSIGN source_row-known_third_component TO FIELD-SYMBOL(<source_component>).
ASSIGN target_row-discovered_component TO FIELD-SYMBOL(<target_component>).
<target_component> = <source_component>.
INSERT target_row INTO TABLE target.
ENDLOOP.
The question and answers may look confusing for future visitors (what is the actual question?), so here is my two cents.
Summary of the question :
You call an external code (1) which gives you an internal table generated dynamically, but you know that all the components are always the same except one which varies but is at the same position, so you'd like to refer to its components statically, except for the one which varies.
(1) so, you can't adapt it.
Your workaround is to define an equivalent internal table statically and the component which varies will be defined as a data reference type (pointer to any data object), then to initialize it by copying the data from the dynamic internal table.
You ask for another better solution because yours consumes extra memory (two internal tables) and decreases the performance (copy process).
Answer :
No better solution
It looks like I was able to pass the values from the fully generic table (type ref to data) to another table that is 1/3 generic (type gty_t_generic_payroll):
methods get_payroll
importing it_rgdir type hrpy_tt_rgdir
returning value(rt_value) type gty_t_generic_payroll.
method get_payroll.
data lt_payroll type gty_t_generic_payroll.
data lt_payroll_aux type ref to data.
field-symbols: <lt_payroll_aux> type standard table.
create data lt_payroll_aux type standard table of (mv_py_struct_type).
assign lt_payroll_aux->* to <lt_payroll_aux> .
call function ' '.
call function ' '
exporting
= mv_relid
= mv_pernr
= xsdbool( gs_parm-use_natio <> abap_true )
tables
= it_rgdir
= <lt_payroll_aux> "table with the values I need
exceptions
= 0.
if sy-subrc <> 0.
return.
endif.
loop at <lt_payroll_aux> assigning field-symbol(<ls_payroll_aux>).
assign component 1 of structure <ls_payroll_aux> to field-symbol(<evp>).
assign component 2 of structure <ls_payroll_aux> to field-symbol(<inter>).
assign component 3 of structure <ls_payroll_aux> to field-symbol(<nat>).
data(ls_value) = value gty_s_generic_payroll(
evp = <evp>
inter = <inter>
).
get reference of <nat> into ls_value-nat.
append ls_value to rt_value. "returning table, with values I need and
"now with 2/3 known types
endloop.
endmethod.
At the end of the day, I acomplished what I needed, but unfortunately I do loose a lot of performance, since I must loop twice in the results now.
to populate the not-so-dynamic-table
to do the actual process of the report (at least it gets pretier lol)
This is the only way because I can't simply use insert lines of dynamic_itab to not_so_dynamic_itab, since the third component is reference .

Pass a read-only variable to a CHANGING parameter

I'd like to display a table from a class instance using CL_SALV_TABLE. However, my table is read-only and it's to be passed to a CHANGING parameter, I'm not allowed to do so.
How can I copy my dynamic reference to something that I can pass? The data type of the attribute can by any table.
Call of method FACTORY of the class CL_SALV_TABLE has failed; the
actual parameter for T_TABLE is write-protected.
DATA(lv_attribute) = 'mt_attribute'. "Dynamic name of class attribute
ASSIGN lr_appclass->(lv_attribute) TO FIELD-SYMBOL(<lt_table>).
cl_salv_table=>factory(
IMPORTING r_salv_table = DATA(lr_salv_table)
CHANGING t_table = <lt_table> ).
You can use RTTS to generate dynamic variables.
To generate a dynamic internal table with same type of original:
DATA: lo_table_desc TYPE REF TO cl_abap_tabledescr, " RTTS table descriptor
lrt_copy TYPE REF TO DATA. " temp data ref
FIELD-SYMBOLS:
<lt_copy> TYPE ANY TABLE.
" original type determination
lo_table_desc ?= cl_abap_tabledescr=>describe_by_data( {HERE_GOES_THE_MEMBER_TABLE} ).
" dynamic allocation
CREATE DATA lrt_copy TYPE HANDLE lo_table_desc.
ASSIGN lrt_copy->* TO <lt_copy>.
" {NOW_USE_<lt_copy>}
Without runtime typing:
ASSIGN lr_appclass->('MT_ATTRIBUTE') TO FIELD-SYMBOL(<member>).
DATA(copied_member) = copy( <member> ).
ASSIGN copied_member->* TO FIELD-SYMBOL(<table>).
cl_salv_table=>factory(
IMPORTING
r_salv_table = DATA(lr_salv_table)
CHANGING
t_table = <table> ).
with
METHODS copy
IMPORTING
data TYPE any
RETURNING
VALUE(result) TYPE REF TO data.
METHOD copy.
CREATE DATA result LIKE data.
ASSIGN result->* TO FIELD-SYMBOL(<result>).
<result> = data.
ENDMETHOD.
I added the method copy to clarify what's happening. Its code can also be added to the main function.

Method call as a parameter for another method call?

i'm new in abap (OO) but developed before in java and wrote a class abap "cl_caretaker" which should handle the operations on database table and the local copy (intern table) of it.
I want to make the following method call:
caretaker->show_table( caretaker->get_users( ) ) .
with:
caretaker = cl_caretaker=>get_instance( ). "singleton instance
METHODS:
"! get a list of all user which registrated for FCP
"!
"! #parameter rt_users | users which are registrated for FCP
get_users
RETURNING value(rt_users) TYPE itty_users,
"! shows the content of a table
"!
"! #parameter it_table | the table we want to visualize
show_table
IMPORTING
value(it_table) TYPE ANY TABLE.
if I split the call in two and store the result of get_users in a tmp variable it works.
DATA:
gt_tmp_users TYPE caretaker->itty_users.
gt_tmp_users = caretaker->get_users( ).
caretaker->show_table( gt_tmp_users ).
So my questions are:
1) is a call like: caretaker->show_table( caretaker->get_users( ) ).
possible and if how?
2) I also tried to create a generic variable, which stores all kind of tables.
Because i don't want to create for each table kind i use a tmp/help variable.
But i got the information that only (german: Formalparameter) dummy parameters of method definitions are allowed to of generic type (eg. TYPE any TABLE ).
Here some stuff I already tried:
DATA:
* tmpanytable TYPE TABLE OF any.
* tmpAnyTable TYPE any.
tmpanytable TYPE REF TO data.
" needed to store a temporal table
FIELD-SYMBOLS: <tmpanytable> TYPE ANY TABLE.
* ASSIGN caretaker->get_users( ) TO <tmpAnyTable>.
* <tmpAnyTable> = caretaker->get_users( ).
* caretaker->get_users( ).
*caretaker->show_table( <tmpAnyTable> ).
*caretaker->show_table( caretaker->get_users( ) ).
*CALL METHOD: caretaker->show_table( IMPORTING it_table = caretaker->get_users ).
*CALL METHOD: caretaker->show_table( it_table = caretaker->get_users( ) ).
*COMPUTE caretaker->show_table( it_table = caretaker->get_users( ) ).
*ASSIGN caretaker->get_users() ->* to <tmpAnyTable>.
*Caretaker->show_table( <tmpAnyTable> ).
*call METHOD caretaker->show_table
* Exporting It_table = caretaker->get_users( ).
* CREATE DATA tmpanytable TYPE STANDARD TABLE OF (dbtab)
* WITH NON-UNIQUE DEFAULT KEY.
* ASSIGN tmpanytable->* TO <tmpanytable>.
* CREATE DATA tmpanytable TYPE tabkind OF any Table .
* ASSIGN tmpanytable->* TO <tmpanytable>.
*GET REFERENCE OF caretaker->get_users() INTO tmpAnyTable.
*caretaker->show_table( tmpAnyTable ) .
Method chaining is possible, and methods in operand positions are possible as well, but you need at least SAP_ABA 702 for that.
You can use generic types to pass a table around without knowing its type at runtime. However, you can't create a table without knowing its type. Comparing it to OO principles, you can handle references to an abstract superclass and pass them along between components, but you can't instantiate the abstract superclass.
The CREATE DATA statement needs a "concrete data type" to work on, not the "abstract super type STANDARD TABLE". The hard part here is deciding who will know about the type and create the data object.
BTW, you may want to take a look at the built-in Object Services - maybe there's no need to reinvent the database access layer wheel yet again.

DB2 SQL array in attribute-defs of user defined type

I have a question concerning user defined types in DB2(v. 9.7.0.441). I want to create a type which has an attribute-array of another user defined type. Let me show you what I mean by a brief (fictional) example:
This is the UDT I want to use in another type
CREATE TYPE sport AS
(
Sport VARCHAR(10)
) MODE DB2SQL;
This is the UDT which should use the one above
CREATE TYPE person AS
(
plays sport ARRAY[3] // 'REF(sport)' or 'plays VARCHAR(10) ARRAY[3]' don't work either
) MODE DB2SQL;
DB2 just says that the token ARRAY[3] is unexpected.
Any hint what could be wrong here? By now it would be enough to have an CHAR Array in a UDT...
Thanks in advance
Ok ok,
according to db2's CREATE TYPE (array) statement "an array type can only be used as the data type of:
A local variable in a compound SQL (compiled) statement
A parameter of an SQL routine
A parameter of a Java procedure (ordinary arrays only)
The returns type of an SQL function
A global variable
and
A variable or parameter defined with an array type can only be used in compound SQL (compiled) statements
"
So its just not possible to use an array type inside a user defined type :-/
I would assume something like the following...
CREATE TYPE sport AS(Sport VARCHAR(10)) MODE DB2SQL;
CREATE TYPE PersonT AS(plays SportT ARRAY[3]) MODE DB2SQL;
CREATE TYPE SportArrayT AS SportT ARRAY[3];
CREATE TYPE PersonT AS (plays SportT SportArrayT) MODE DB2SQL;
However, the 3rd statement fails. Obviously an array of a user-defined type (or REF(SportT)) is not allowed :-(
Have a look at the doc for CREATE TYPE (array).
I'm not really sure what you're trying to do but the examples they give are like this:
CREATE TYPE CAPITALSARRAY AS VARCHAR(30) ARRAY[VARCHAR(20)]