Joins in postgresql -

how change oracle sql postgresql

select prd.name, pkg.name, si.name  service_items si, service_link sl, products prd, packages pkg, product_package_link ppl  ppl.id='3'  , prd.id=ppl.product_id , pkg.id=ppl.package_id , sl.product_package_id(+)=ppl.id , si.id(+)=sl.service_item_id  ; 

try

select prd.name, pkg.name, si.name    products prd join product_package_link ppl     on prd.id = ppl.product_id join packages pkg     on pkg.id = ppl.package_id left join service_link sl     on ppl.id = sl.product_package_id left join service_items si     on si.id  = sl.service_item_id  ppl.id = '3'