Not able to LEFT OUTER JOIN three tables - abap

Question

I've got a problem.
Currently I have three tables, the first table is the main table and if there is no record in the second table, write it too. But if a record exists in the second table, so from the third table display "dispo" information..
I want to use three SAP table - lagp, lqua and marc.
Me goal is write all stock positions from lagp.
2x LEFT JOIN doesnt work: "Unable to compare with"B~MATNR". A table can be joined with a maximum of one other table usign LEFT OUTER JOIN.
Structure:
TYPES:
BEGIN OF t_work,
lgnum TYPE lgnum,
lgtyp TYPE lgtyp,
lgpla TYPE lgpla,
bdatu TYPE lagp_bdatu,
matnr TYPE matnr,
verme TYPE lqua_verme,
meins TYPE meins,
dispo TYPE dispo,
END OF t_work.
DATA:
lt_work TYPE TABLE OF t_work INITIAL SIZE 0,
ls_work LIKE LINE OF lt_work.
And SQL command:
SELECT a~lgnum a~lgtyp a~lgpla a~bdatu b~matnr b~verme b~meins c~dispo FROM lagp AS a
LEFT JOIN lqua AS b ON a~lgnum = b~lgnum AND a~lgtyp = b~lgtyp AND a~lgpla = b~lgpla
INNER JOIN marc AS c ON b~matnr = c~matnr AND b~werks = c~werks
INTO TABLE lt_work
WHERE a~lgnum IN so_lgnum
AND a~lgtyp IN so_lgtyp
AND a~skzua EQ space
AND a~skzue EQ space.
But as result is only one stock position - http://i.stack.imgur.com/1sEEo.png
Can you tell me, how the SQL code has look?
Thank you

Answer 1

Try:
SELECT a~lgnum, a~lgtyp, a~lgpla, a~bdatu, b~matnr, b~verme, b~meins, c~dispo
FROM lagp AS a
LEFT JOIN ( lqua AS b
JOIN marc AS c ON b~matnr = c~matnr AND b~werks = c~werks )
ON a~lgnum = b~lgnum AND a~lgtyp = b~lgtyp AND a~lgpla = b~lgpla
INTO TABLE #lt_work
WHERE a~lgnum IN #so_lgnum
AND a~lgtyp IN #so_lgtyp
AND a~skzua EQ #space
AND a~skzue EQ #space.
Other option would be to put the join between LQUA and MARC in a view and do an outer join with the view. Or split out the select on MARC and do that while looping at the data found with a select on LAGP and LQUA.

Answer 2

I got that fine working code:
SELECT ma~matnr ma~mtart ma~ernam ma~ersda ma~laeda
de~maktx as maktx_de fr~maktx as maktx_fr it~maktx as maktx_it
FROM mara as ma
LEFT JOIN MAKT as de ON de~matnr = ma~matnr AND de~spras = 'DE'
LEFT JOIN MAKT as fr ON fr~matnr = ma~matnr AND fr~spras = 'FR'
LEFT JOIN MAKT as it ON it~matnr = ma~matnr AND it~spras = 'IT'
INTO CORRESPONDING FIELDS OF TABLE g_it_material
WHERE ma~ernam IN so_ERNAM
AND ma~laeda IN so_LAEDA
AND ma~matnr IN so_MATNR.
and it works fine. What did you say about multi-leftjoins?