Dynamic INTO clause in OpenSQL?

Question

I'm attempting to write a program that will grab the content from fields from a table both specified by the user on the selection screen.

For example, the user could specify the fields equnr, b_werk, b_lager from the table eqbs.

I've been able to accomplish this like so:

" Determine list of fields provided by user
DATA(lv_fields) = COND string(
  WHEN p_key3 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |{ p_key1 }, { p_key2 }, { p_key3 }, { p_string }|
  WHEN p_key2 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |{ p_key1 }, { p_key2 }, { p_string }|
  WHEN p_key2 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |{ p_key1 }, { p_string }| ).

DATA: lv_field_tab TYPE TABLE OF line.
APPEND lv_fields TO lv_field_tab.

" Determine table specified by user and prepare for Open SQL query
DATA t_ref TYPE REF TO data.

FIELD-SYMBOLS: <t>    TYPE any,
               <comp> TYPE any.

CREATE DATA t_ref TYPE (p_table).
ASSIGN t_ref->* TO <t>.
ASSIGN COMPONENT lv_fields OF STRUCTURE <t> TO <comp>.

" Prepare result container
DATA: lt_zca_str_to_char TYPE TABLE OF zca_str_to_char,
      ls_zca_str_to_char TYPE zca_str_to_char.

SELECT (lv_field_tab) FROM (p_table) INTO (@ls_zca_str_to_char-key1, @ls_zca_str_to_char-key2, @ls_zca_str_to_char-key3, @ls_zca_str_to_char-string).
  APPEND ls_zca_str_to_char TO lt_zca_str_to_char.
ENDSELECT.

This will correctly populate lt_zca_str_to_char with data from the table specified by the user.

However, this implies that the user is always providing p_key1, p_key2, and p_key3. I could perform a different selection statement based on how many key fields the user provides, but what's the fun in that?

I set out to solve this like this:

DATA(lv_results) = COND string(
  WHEN p_key3 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |(@ls_zca_str_to_char-key1, @ls_zca_str_to_char-key2, @ls_zca_str_to_char-key3, @ls_zca_str_to_char-string)|
  WHEN p_key2 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |(@ls_zca_str_to_char-key1, @ls_zca_str_to_char-key2, @ls_zca_str_to_char-string)|
  WHEN p_key2 IS NOT INITIAL AND p_string IS NOT INITIAL THEN
    |(@ls_zca_str_to_char-key1, @ls_zca_str_to_char-string)| ).

SELECT (lv_field_tab) FROM (p_table) INTO (@lv_results).
  APPEND ls_zca_str_to_char TO lt_zca_str_to_char.
ENDSELECT.

This will activate, and when I get to my Open SQL query (from a Z table, only filling out the first two of three possible key fields), the values are the following:

lv_field_tab = GUID, TEXT_ID, TEXT_DATA (Good)

p_table = ZCR_TRANS_TEXT (Good)

lv_results = (@ls_zca_str_to_char-key1, @ls_zca_str_to_char-key2, @ls_zca_str_to_char-string) (Good, 3 = 3!)

But, since I'm assuming the compiler is seeing (@lv_results) as one single variable, the program dumps with the following error:

The current ABAP program attempted to execute an Open SQL statement containing a dynamic entry. The parser returned the following error: "The field list and the INTO list must have the same number of elements."

Is it possible for me to use the new Open SQL syntax to accomplish my dynamic INTO clause in harmony with my dynamic field list?

score 4 · Accepted Answer · answered Mar 13 '18 at 19:00

The brackets on the INTO do not do what you expect, from the ABAP help:

... INTO (@dobj1, @dobj2, ... )

Effect

If the results set consists of multiple columns or aggregate expressions specified explicitly in the SELECT list, a list of elementary data objects dobj1, dobj2, ... (in parentheses and separated by commas) can be specified after INTO.

In your case you only have one value in there so you can only select one column and the data will be passed in the variable LV_RESULT. Not what you are looking for. Since you want to fill the fields of an existing structure the INTO CORRESPONDING FIELDS OF construct will work here. And you can use TABLE to make your command more efficient as well. This leads to:

SELECT (lv_field_tab) FROM (p_table) 
       INTO CORRESPONDING FIELDS OF TABLE @lt_zca_str_to_char.

Thanks Gert. Just a note for anyone reading this in the future, in order for me to make this work, I had to modify my `lv_fields` assignment to include `AS key1`, `AS key2` etc. I really like this answer because it allowed me to write the results straight to the table instead of a structure. — gkubed, Mar 14 '18 at 16:14

score 2 · Answer 2 · answered Mar 13 '18 at 20:24

As said previously, you may use INTO CORRESPONDING FIELDS OF ..., but it's not mandatory, it's only for simplifying the code.

So, instead of using CORRESPONDING FIELDS, you may create a structure dynamically (RTTC) with its components corresponding to the columns in LV_FIELD_TAB, and you may then use:

SELECT (lv_field_tab) FROM (p_table) INTO @<structure> ... ENDSELECT.

But of course, as explained by Gert Beukema, you should better do only one SELECT, by creating an internal table dynamically with the same logic as for the structure above, and you may then use:

SELECT (lv_field_tab) FROM (p_table) INTO TABLE @<internal table> ...

Refer to the many examples in the web how to create data objects dynamically with RTTC.

score 1 · Answer 3 · answered Mar 13 '18 at 16:47

Do not use a fields list for your INTO clause.

Try with INTO CORRESPONDING FIELDS OF TABLE

must be a FIELD-SYMBOL type any table, and the rest of the logic is up to you (to put the proper information from your generic and almost-empty to your specific destination one).

Dynamic INTO clause in OpenSQL?

3 Answers3