mysql - SQL Like or REGEXP filter results even when everything should be matched -

this have

select node.nid nid, node.type node_type, product.*  ml_node node  left join ml_content_type_product product    on node.vid = product.vid  (node.type in('product'))    , product.field_sockel_value regexp '.*'    , product.field_artikel_value regexp '.*'    , product.field_leistung_value regexp '.*'   , product.field_licht_farbe_value regexp '.*'    , product.field_rubrik_value regexp '.*'    , product.field_artikelgruppe_value regexp '.*'  order product.field_artikel_value 

having these where-conditions assume gives same results as:

select node.nid nid, node.type node_type, product.*  ml_node node  left join ml_content_type_product product    on node.vid = product.vid  (node.type in('product'))  order product.field_artikel_value 

but not. first returns 494 rows , last 1 gives 717. there's missing bunch of rows. when use query

select node.nid nid, node.type node_type, product.*  ml_node node  left join ml_content_type_product product    on node.vid = product.vid  (node.type in('product'))    , product.field_artikel_value regexp '.*'    , product.field_leistung_value regexp '.*'   , product.field_rubrik_value regexp '.*'    , product.field_artikelgruppe_value regexp '.*'  order product.field_artikel_value 

i 717 rows. so… makes removed conditions special? columns of type longtext (because cms so) , have exact same attributes.

btw noticed same behavior when using instead of regexp.

since have left join lines product.field_sockel_value or product.field_licht_farbe_value null. these line got filtered in where clause