Sorry is not that select.
The coorect select with error is:
SELECT *
FROM a957
INTO TABLE a957
WHERE kappl EQ kappl
AND kschl EQ kschl
AND vkorg EQ vkorg
AND matnr IN smatnr
AND kfrst EQ space
AND datbi GE sy-datum.
IF sy-subrc EQ 0.
DELETE a957 WHERE NOT datab BETWEEN dtcrt AND sy-datum.
ENDIF.