Thread: Issue adding foreign key

I have 2 existing tables in my db:

iss=> \d pollgrpinfo
             Table "public.pollgrpinfo"
    Column     |          Type          | Modifiers
---------------+------------------------+-----------
 pollgrpinfoid | integer                | not null
 pollgrpid     | integer                | not null
 name          | character varying(100) |
 descript      | character varying(200) |
Indexes:
    "pollgrpinfo_pkey" primary key, btree (pollgrpinfoid)
    "pollgrpinfo_pollgrpid_key" unique, btree (pollgrpid)

iss=> \d notpoll
                   Table "public.notpoll"
   Column    |          Type          |      Modifiers
-------------+------------------------+---------------------
 notpollid   | integer                | not null
 pollgrpid   | integer                |
 notgroupsid | integer                |
 alerting    | character(1)           | default 'y'::bpchar
 disuser     | character varying(50)  |
 distime     | integer                |
 alertingcom | character varying(200) |
Indexes:
    "notpoll_pkey" primary key, btree (notpollid)
    "notpoll_pollgrpid_key" unique, btree (pollgrpid)
    "notpoll_alerting_index" btree (alerting)
Triggers:
    "RI_ConstraintTrigger_2110326" AFTER INSERT OR UPDATE ON notpoll
FROM notgroups NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH ROW EXECUTE
PROCEDURE "RI_FKey_check_ins"('notgroups_exists', 'notpoll',
'notgroups', 'UNSPECIFIED', 'notgroupsid', 'notgroupsid')

I am trying to add a foreign key to the notpoll table

iss=> alter table notpoll add constraint pollgrp_exists foreign
key(pollgrpid) references pollgrpinfo on delete cascade;
ERROR:  insert or update on table "notpoll" violates foreign key
constraint "pollgrp_exists"
DETAIL:  Key (pollgrpid)=(7685) is not present in table "pollgrpinfo".

I have verified that the information is in the pollgrpinfo table:

iss=> select * from pollgrpinfo where pollgrpid=7685;
 pollgrpinfoid | pollgrpid | name | descript
---------------+-----------+------+----------
           767 |      7685 | HTTP |
(1 row)


I could use a suggestion on how to proceed in troubleshooting the error
message.  I am running 7.4.5

Thanks,
Woody

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iGLASS Networks
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www.iglass.net

george.woodring@iglass.net ("George Woodring") writes:

> I have 2 existing tables in my db:
>
> iss=> \d pollgrpinfo
>              Table "public.pollgrpinfo"
>     Column     |          Type          | Modifiers
> ---------------+------------------------+-----------
>  pollgrpinfoid | integer                | not null
>  pollgrpid     | integer                | not null
>  name          | character varying(100) |
>  descript      | character varying(200) |
> Indexes:
>     "pollgrpinfo_pkey" primary key, btree (pollgrpinfoid)
>     "pollgrpinfo_pollgrpid_key" unique, btree (pollgrpid)
>
> iss=> \d notpoll
>                    Table "public.notpoll"
>    Column    |          Type          |      Modifiers
> -------------+------------------------+---------------------
>  notpollid   | integer                | not null
>  pollgrpid   | integer                |
>  notgroupsid | integer                |
>  alerting    | character(1)           | default 'y'::bpchar
>  disuser     | character varying(50)  |
>  distime     | integer                |
>  alertingcom | character varying(200) |
> Indexes:
>     "notpoll_pkey" primary key, btree (notpollid)
>     "notpoll_pollgrpid_key" unique, btree (pollgrpid)
>     "notpoll_alerting_index" btree (alerting)
> Triggers:
>     "RI_ConstraintTrigger_2110326" AFTER INSERT OR UPDATE ON notpoll
> FROM notgroups NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH ROW EXECUTE
> PROCEDURE "RI_FKey_check_ins"('notgroups_exists', 'notpoll',
> 'notgroups', 'UNSPECIFIED', 'notgroupsid', 'notgroupsid')
>
> I am trying to add a foreign key to the notpoll table
>
> iss=> alter table notpoll add constraint pollgrp_exists foreign
> key(pollgrpid) references pollgrpinfo on delete cascade;
> ERROR:  insert or update on table "notpoll" violates foreign key
> constraint "pollgrp_exists"
> DETAIL:  Key (pollgrpid)=(7685) is not present in table "pollgrpinfo".
>

When expressed as "FOREIGN KEY (foo) REFERENCES mytable"  postgresql
assumes that foo references the PRIMARY KEY  for table mytable. If you
are not referencing the primary key, you need to tell postgresql which
column  e.g. FOREIGN KEY (foo) REFERNCES mytable(foo).


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