Re: Problem with SqlState=23505 when inserting rows - Mailing list pgsql-general

On 1/15/20 8:40 AM, Werner Kuhnle wrote:
> 
> 
> Hi,
> 
> I'm new to pg and want to port an application and database from ms sql to pg v12.
> 
> Together with my application a database containing initial standard data
> which is needed by the application is also installed.
> This is done via execution of SQL scripts.
> 
> Every table of the db has an id column and id column values are also contained in the SQL script
> which is necessary for consistence.
> 
> In MS SQL id columns were defined as
> id INT IDENTITY PRIMARY KEY
> 
> In PG id columns are defined as
> id SERIAL PRIMARY KEY
> 
> Importing the SQL script for initial standard data with PG Admin 4 works without any problem.
> 
> But afterwards I get error messages with SqlState=23505 when inserting new rows into that databases by my
application.
> My application does not provide id values when doing INSERT INTO statements so that new id values are automatically
providedby the database.
 
> 
> This worked in MS SQL DB without any problems.
> 
> But in PG there seem to be conflicts between the row id values of the rows that were
> initially imported and the row id values which are automatically provided by the database
> if values for id column are missing in INSERT INTO
> When automatically providing id values PG seems to ignore the already existing id values.
> 
> I've tried to using the newer definition:
> id int GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY
> but that does not solve the problem.
> 
> Is there a way to define id columns to that when the database provides values,
> it recognizes already existing values avoiding conflicts.
> 
> Any hint is highly appreciated.

My guess is that the SERIAL was defined for the column, then the data 
was added with id values, but the counter for the sequence behind the 
SERIAL was not updated to a value greater the the last id added. To verify:

1) In psql do \d some_table and look for the sequence name in the 
default column e.g:

production=# \d order_header
                                                  Table 
"public.order_header"
     Column    |              Type              | Collation | Nullable | 
                       Default

--------------+--------------------------------+-----------+----------+------------------------------------------------------
  order_no     | integer                        |           | not null | 
nextval('order_header_order_no_seq'::text::regclass)

So 'order_header_order_no_seq'

2) Then:

production=# select * from order_header_order_no_seq;
  last_value | log_cnt | is_called
------------+---------+-----------
         252 |       0 | t
(1 row)

3) Then in your case:

select max(id) from some_table


Postgres also has UPSERT:

https://www.postgresql.org/docs/12/sql-insert.html

Look for
    ON CONFLICT Clause

Though I don't think this is what you need at this point.

> 
> Regards
> 
> Werner
> 
> 
> 
> 
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com