在 SELECT 查询中连接两列并获得 MAX

Question

I have a table with BUKRS, GJAHR, MONAT and I want to select the MAX GJAHR & MONAT as follow:

SELECT MAX( concat( gjahr, monat ) ) AS year_monat
      FROM zfiou_percentage
        INTO data(lv_year_month)
      WHERE bukrs = '5555' AND
            concat( gjahr, monat ) <= '202001'
      GROUP BY year_monat.

So in table we have :

BUKRS  GJAHR  MONAT
5555   2019   09   
5555   2019   10  
5555   2019   11  
5555   2020   02  

How can I get the line 5555 2019 11 ?

Answer 1

The year and month columns ( GJAHR and MONAT ) are numerical text columns (characters from 0 to 9), but MAX accepts only a numerical (not text) column, so you may use CAST to convert these "texts" to numbers as follows:

SELECT MAX( CAST( gjahr AS DEC ) * 100 + CAST( monat AS DEC ) ) AS year_monat
      FROM bkpf
      WHERE bukrs = '3001' AND
            concat( gjahr, monat ) <= '202001'
        INTO @DATA(lv_year_month).

It has been tested in an ABAP 7.52 SP 1 system.

NB: the CAST function accepts the DEC type only since ABAP 7.50. I use the table BKPF instead of zfiou_percentage because it exists in all R/3, ECC, S/4 systems.

Answer 2

Concatenating the two columns like you are planning to is only possible since version 7.50, as indicated by the documentation . What is your version?

If you cannot get it to work or don't have the required ABAP version, you can do the following. For more information, read up on subqueries .

DATA: p_bukrs   TYPE bukrs,
      lt_result TYPE TABLE OF zfiou_percentage.

SELECT *
  FROM zfiou_percentage
  INTO CORRESPONDING FIELDS OF TABLE lt_result
 WHERE bukrs = p_bukrs 
   AND gjahr >= ALL ( SELECT gjahr
                        FROM zfiou_percentage 
                       WHERE bukrs = p_bukrs )
   AND monat >= ALL ( SELECT monat
                        FROM zfiou_percentage 
                       WHERE bukrs = p_bukrs 
                         AND gjahr >= ALL ( SELECT gjahr
                                              FROM zfiou_percentage 
                                             WHERE bukrs = p_bukrs ) ).

Explanation :

• select all datasets
• of the z-table
• into the itab (because there could be multiple rows with the same max gjahr and month)
• where:
  1. normal conditions (make sure to use them in every subquery as well)
  2. AND the year is the highest of all years existing in the z-table
  3. AND the month is the highest of all months of the datasets with the highest years

Edit : (Of course you could also select your data in multiple steps, using SELECT and SELECT ... FOR ALL ENTRIES ... , or SELECT and LOOP . You will have to think about and test which solution will be the most efficient, easy to understand and suited for your problem.)

Answer 3

SELECT
    gjahr AS year,
    monat AS month
  FROM zfiou_percentage
    INTO TABLE DATA(selected_maxes)
  WHERE bukrs = '5555'
    AND ( gjahr < '2020'
      OR gjahr = '2020' AND monat <= '01' )
  ORDER BY
    gjahr DESC,
    monat DESC
  UP TO 1 ROWS.

DATA(selected_max) = selected_maxes[ 1 ].
DATA(max_date) = |{ selected_max-year }{ selected_max-month }|.