Hi ,
Please pass PRPS-PSPNR to BSEG-PROJK field and it should work . Please check if there is valid data in BSEG for that PRPS-PSPNR. I have tried below code and it worked.
DATA:lv_wbs TYPE PS_POSNR VALUE '01111111', (numeric value)
lv_belnr TYPE belnr_d,
lv_projk TYPE PS_PSP_PNR.
SELECT SINGLE belnr
projk
FROM bseg
Into (lv_belnr, lv_projk)
WHERE bukrs = 'XXXX'
AND projk = lv_wbs.
IF sy-subrc = 0.
WRITE:lv_belnr.
ENDIF.
Thanks
Sri