SELECT 

P.PRODUCTNUM, 

A.CONTRACTNUM, 

A.INSTAGREENUM, --ABNR

A.METERINGPOINT

FROM (

    SELECT DISTINCT P.PRODUCTNUM

    FROM XLN_EXU_PRODUCTTABLE P

    WHERE P.DELIVERYCATEGORY = 'el-ext'

    AND P.COMPANYID = 'xdb'

    --AND P.PRODUCTTXT LIKE '%prod%'

    AND P.REGISTRATIONENDDATE = '1900-01-01'

    AND P.MAINPRODUCT = 1

) P

CROSS APPLY (

    SELECT TOP 1 C.CONTRACTNUM, C.INSTAGREENUM, D.METERINGPOINT

    FROM XLN_EXU_CONTRACTPARTTABLE C

    INNER JOIN XLN_EXU_DELPOINT D

    ON D.ATTACHMENTNUM = C.INSTAGREENUM

    AND D.DELIVERYCATEGORY = C.DELIVERYCATEGORY

    AND D.COMPANYID = C.COMPANYID

    WHERE C.PRODUCTNUM = P.PRODUCTNUM

    AND C.DELIVERYCATEGORY = 'el-ext'

    AND C.COMPANYID = 'xdb'

    AND (C.ENDDATE = '1900-01-01' OR C.ENDDATE > GETDATE())

) A