Hi,

Today I discovered that if there is a compund primary key on a table, I can 
not create a reference from another table to one of the fields in the primary 
key..

Look at this..

phd=# create table tmp1(a integer,b integer,primary key(a,b));
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index 'tmp1_pkey' for 
table 'tmp1'
CREATE TABLE
phd=# create table tmp2(a integer references tmp1(a));
NOTICE:  CREATE TABLE will create implicit trigger(s) for FOREIGN KEY check(s)
ERROR:  UNIQUE constraint matching given keys for referenced table "tmp1" not 
found
phd=# drop table tmp1;
DROP TABLE
phd=# create table tmp1(a integer unique,b integer primary key);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index 'tmp1_pkey' for 
table 'tmp1'
NOTICE:  CREATE TABLE / UNIQUE will create implicit index 'tmp1_a_key' for 
table 'tmp1'
CREATE TABLE
phd=# create table tmp2(a integer references tmp1(a));
NOTICE:  CREATE TABLE will create implicit trigger(s) for FOREIGN KEY check(s)
CREATE TABLE
phd=# select version();
                               version
---------------------------------------------------------------------
 PostgreSQL 7.3.2 on i386-portbld-freebsd4.7, compiled by GCC 2.95.4
(1 row)


Note that I do not require unique check on tmp2. It is perfectly acceptable to 
have duplicate values in table tmp2. However no duplicates are allowed in 
table tmp1.

I consider this as a bug but given my understanding of sql, I won't count on 
it. Any comments? 

The workaround shown here is acceptable as I don't really need a compound 
primary key. But If I need, I know it won't work..

TIA..

 Shridhar

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org

Reply via email to