Conceptual Data Model match MySQL script?
You could enfoce your (1,4) cardinality, eg.

create table tbl2
    (idTbl1  int references tbl1,
     Tbl2Id int check (Tbl2Id in (1,2,3,4)) enforced,
     constraint tbl2_PK primary key (idTbl1,Tbl2Id))
;