On 9/23/25 23:44, Juan Rodrigo Alejandro Burgos Mella wrote:
The insert works because there is no data in the repo table that
conflicts with the entered full name.
Except this part:
SELECT 1/COUNT(*)
FROM org
WHERE name = 'org0'
AND owner = 'wrong user';
will cause a divide by 0 error and abort the transaction preventing the
INSERT from happening.
Example:
test=# begin ;
BEGIN
test=*# select 1/0;
ERROR: division by zero
test=!# select 1;
ERROR: current transaction is aborted, commands ignored until end of
transaction block
test=!# rollback ;
ROLLBACK
JRBm
El mar, 23 sept 2025, 23:19, Samuel Marks <samuelma...@gmail.com
<mailto:samuelma...@gmail.com>> escribió:
Ok so you're thinking I give up on putting it all in one query and
instead use a transaction? - Is that the recommended way?
```sql
TRUNCATE repo, org;
INSERT INTO org(name, owner) VALUES ('org0', 'user0');
```
```sql
START TRANSACTION READ WRITE;
SELECT 1/COUNT(*)
FROM org
WHERE name = 'org0'
AND owner = 'wrong user';
INSERT INTO repo (id, full_name, org)
VALUES (0, 'org0/name0 by wrong user', 'org0')
ON CONFLICT (full_name) DO UPDATE
SET full_name = EXCLUDED.full_name,
org = EXCLUDED.org
RETURNING id;
COMMIT;
```
On Tue, Sep 23, 2025 at 7:25 PM Juan Rodrigo Alejandro Burgos Mella
<rodrigoburgosme...@gmail.com <mailto:rodrigoburgosme...@gmail.com>>
wrote:
>
> Hi Samuel
>
> Using ON CONFLICT is a headache.
> It's better to use the versatility of a Trigger: you have the
full record at your fingertips, and if you're going to UPDATE, you
have the previous record too.
> There's much more control.
>
> Also, you can always count on the beloved foreign keys, which are
also quite useful.
>
> Atte.
> JRBM
>
>
> El mar, 23 sept 2025 a las 15:37, Samuel Marks
(<samuelma...@gmail.com <mailto:samuelma...@gmail.com>>) escribió:
>>
>> Attempt:
>> ```sql
>> CREATE TABLE org
>> (
>> "name" VARCHAR(50) PRIMARY KEY,
>> owner VARCHAR(50) NOT NULL
>> );
>>
>> CREATE TABLE repo
>> (
>> "id" INTEGER PRIMARY KEY,
>> full_name VARCHAR(255) UNIQUE NOT NULL,
>> org VARCHAR(50) NOT NULL REFERENCES org
("name")
>> );
>>
>> INSERT INTO org(name, owner) VALUES ('org0', 'user0');
>>
>> INSERT INTO repo (id, full_name, org)
>> VALUES (0, 'org0/name0 by wrong user', 'org0')
>> ON CONFLICT (full_name) DO UPDATE
>> SET full_name = EXCLUDED.full_name,
>> org = EXCLUDED.org
>> WHERE EXISTS (SELECT 1
>> FROM org org_tbl
>> WHERE org_tbl.name <http://org_tbl.name> =
EXCLUDED.org
>> AND org_tbl.owner = 'wrong user')
>> RETURNING *;
>>
>> SELECT * FROM repo WHERE id = 0;
>> ```
>>
>> This all succeeds. It should fail because the 'wrong user' is trying
>> to create a new—or update an existing—repo.
>>
>> Thanks for all suggestions
>>
>>
--
Adrian Klaver
adrian.kla...@aklaver.com
