Enforcing Join condition

Is there a way to force join conditions in queries i.e. When a join is
made to a table on a particular field, another column should also be
checked?

CREATE TABLE test (info_type varchar(3), info_reference integer);
(depending on info_type, info_reference will contain key values from
different tables)

INSERT INTO test (info_type, info_reference) values ('abc','111'); ---
111 from tableA
INSERT INTO test (info_type, info_reference) values ('def','101');
--- 101 from tableB
INSERT INTO test (info_type, info_reference) values ('abc','119'); ---
119 from tableA
INSERT INTO test (info_type, info_reference) values ('def','103');
--- 103 from tableB
INSERT INTO test (info_type, info_reference) values ('def','104');
--- 104 from tableB
INSERT INTO test (info_type, info_reference) values ('def','105');
--- 105 from tableB
INSERT INTO test (info_type, info_reference) values ('def','111');
--- 111 from tableB

Now when joining tableA or tableB with test, joining only
info_reference will be wrong, we should also mention the info_type
value.

1. Is this an appropriate design for this requirement?
2. Is there a way to enforce the dual condition checking on all
queries. If a join is made to info_reference, info_type should also be
specified?

Thanks.

Ma Sivakumar
--
மா சிவகுமார்
எல்லோரும் எல்லாமும் பெற வேண்டும்
http://masivakumar.blogspot.com