Casting from a Packed(8) type to a TMSTMP (DEC15) type in a Unicode system (and back)

Question

Background:

I have several tables that are connected for maintenance in a view cluster (SE54). Each of these tables have the standard Created/Changed By/On fields. For created data updating the fields are easy, and I use event 05 (On Create) in the Table Maintenance generator. For defaulting the changing fields it's a little bit more involved. I have to use event 01 (Before Save), and then update the tables TOTAL[] and EXTRACT[] with the field values as needed.

When maintaining the table in SM30, the format of TOTAL[] and EXTRACT[] is the same as the view I'm maintaining with an additional flag to identify what type of change is made (update/create/delete)

However, when maintaining in SM54 (which is the business requirement), the format of TOTAL[] and EXTRACT[] is just an internal table of character lines.

Problem:

I can figure out what the type of the table that is being edited is. But when I try to move the character line to the type line I get the following run-time errors: (Depending on how I try to move/assign it)

ASSIGN_BASE_TOO_SHORT
UC_OBJECTS_NOT_CONVERTIBLE
UC_OBJECTS_NOT_CHAR

All my structures are in the following format:

*several generic (flat) types
CREATED    TYPE TMSTMP,  "not a flat type
CHANGED    TYPE TMSTMP,  "not a flat type
CREATED_BY TYPE ERNAM,
CHANGED_BY TYPE AENAM,

The root of the problem is that the two timestamp fields are not flat types. I can see in the character line, that the timestamps are represented by 8 Characters.

Edit: Only after finding the solution could I identify the Length(8) field as packed.

I have tried the following in vain:

"try the entire structure - which would be ideal
assign ls_table_line to <fs_of_the_correct_type> casting.  

"try isolating just the timestamp field(s)
assign <just_the_8char_representation> to <fs_of_type_tmpstmp> casting.

I've tried a few other variations on the "single field only" option with no luck.

Any ideas how I can cast from the Character type to type TMSTMP and then back again in order to update the internal table values?

Is there any reason you chose to use timestamps for the database fields instead of the widely used separate date/time fields (ERDAT/ERTIM, ...)? — vwegert
@vwegert None other than I was dictated the design :(. ERDAT/ERTIM would have been great as they are flat structures which in return makes this whole thing go away. We do interface with a Java System, but I doubt that there is any real technical reason to use timestamps (it's not even a multiple-timezone system). — Esti

Esti Esti · Accepted Answer · 2013-06-10T03:52:34

I've found that the following works:

In stead of using:

field-symbols: <structure> type ty_mystructure,
               <changed>   type tmstmp.

assign gv_sapsingle_line to <structure> casting. "causes a runtime error
assign gv_sap_p8_field   to <changed> casting.   "ditto

I used this:

field-symbols: <structure> type any,
               <changed>   type any.

assign gv_sapsingle_line to <structure> casting type ty_mystructure.
assign gv_sap_p8_field   to <changed> casting type ty_tmstmp.

For some reason it didn't like that I predefined the field symbols.

I find that odd as the documentation states the following:

Casting with an Implicit Type Declaration Provided the field symbol is either fully typed or has one of the generic built-in ABAP types – C, N, P, or X – you can use the following statement:

ASSIGN ... TO <FS> CASTING.

When the system accesses the field symbol, the content of the assigned data object is interpreted as if it had the same type as the field symbol.

I can only assume that my structure wasn't compatible (due to the P8 -> TMSTMP conversion)

The length and alignment of the data object must be compatible with the field symbol type. Otherwise the system returns a runtime error. If the type of either the field symbol or the data object is – or contains – a string, reference type, or internal table, the type and position of these components must match exactly. Otherwise, a runtime error occurs.

Casting from a Packed(8) type to a TMSTMP (DEC15) type in a Unicode system (and back)

1 Answers