I am coming from a mssql world and moving over to postgres. I am trying to create a new procedure from a query I wrote and it fails on creation. I am using pgAdmin 4 to create the proc and I've tried copy-pasting the query into the "code" tab of the dialog box.
What I'm trying to accomplish is inserting a bunch of rows into a table and outputting the ids from the identity column into a temporary table. I will be using those ids for more work further down the line, but it's failing before it is even usable. The way I did it in MSSQL was I had a table variable and used "output inserted.id" to get those values to insert into the table variable.
From what I understand, I have to create a temp table and use the returning keyword in postgres. The following query works if I run it in a query window
CREATE TEMPORARY TABLE temp_table
(
temp_id integer
);
WITH ROWS AS
(
INSERT INTO table_a
(some_name_a)
SELECT some_name_b
FROM table_b
RETURNING id)
INSERT INTO temp_table(temp_id)
SELECT id FROM ROWS;
But when I try to create the procedure for that I get an error saying
"ERROR: syntax error at or near "CREATE" LINE 3: AS $BODY$CREATE TEMPORARY TABLE temp_table^"
Here is what the create proc code looks like:
CREATE OR REPLACE PROCEDURE public.temp()
LANGUAGE 'plpgsql'
AS $BODY$
CREATE TEMPORARY TABLE temp_table
(
temp_id integer
);
WITH ROWS AS
(
INSERT INTO table_a
(some_name_a)
SELECT some_name_b
FROM table_b
RETURNING id)
INSERT INTO temp_table(temp_id)
SELECT id FROM ROWS;
$BODY$;
I have 2 insert queries.
In the second insert query, I need the first insert returned id.
I am doing those queries as a transaction, because they depend each other.
So, is it possible to get the last insert id before committing transaction in postgres in Golang.
Postgres supports the returning keyword to select the inserted id:
INSERT INTO YourTable (col1, col2) VALUES ('Value1', 'Value2') RETURNING id;
I've stored some PDF exports in the repository which are generated by the scheduler. After 36 hours I need to delete those PDF's.
Table1
id(pk of table2), file_type, data
table2
id, name, label, created_date, updated_date
Now how can I write a trigger which can delete the records from Table1 and Table2 after 36 hours.
I've written this but It is executing only when an Insert is done. I wanted it to run even when none of the even is occured.
CREATE OR REPLACE FUNCTION ContentResource_Delete() RETURNS trigger AS $ContentResource_Delete$
BEGIN
delete from jicontentresource jicr USING jiresource jir
where jicr.id = jir.id and jicr.file_type='pdf' and trunc(EXTRACT(EPOCH FROM now() - creation_date)/3600) >=1 ;
delete from jiresource where name like '%.pdf' and trunc(EXTRACT(EPOCH FROM now() - creation_date)/3600) >=1 ;
RETURN NULL;
END;$ContentResource_Delete$ LANGUAGE plpgsql;
CREATE TRIGGER ContentResource_Delete AFTER INSERT ON jiresource FOR EACH ROW EXECUTE PROCEDURE ContentResource_Delete();
Hi all I got the solution, instead of using triggers I've used pgAgent and configured. If anyone facing issues while scheduling apart from default database (i.e. postgres) then in the step,ConnectionType should be Remote, connection string should be IP Address instead of localhost , specify the password and provide the databasename. Refer the Image
I'm not sure if its standard SQL:
INSERT INTO tblA
(SELECT id, time
FROM tblB
WHERE time > 1000)
What I'm looking for is: what if tblA and tblB are in different DB Servers.
Does PostgreSql gives any utility or has any functionality that will help to use INSERT query with PGresult struct
I mean SELECT id, time FROM tblB ... will return a PGresult* on using PQexec. Is it possible to use this struct in another PQexec to execute an INSERT command.
EDIT:
If not possible then I would go for extracting the values from PQresult* and create a multiple INSERT statement syntax like:
INSERT INTO films (code, title, did, date_prod, kind) VALUES
('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');
Is it possible to create a prepared statement out of this!! :(
As Henrik wrote you can use dblink to connect remote database and fetch result. For example:
psql dbtest
CREATE TABLE tblB (id serial, time integer);
INSERT INTO tblB (time) VALUES (5000), (2000);
psql postgres
CREATE TABLE tblA (id serial, time integer);
INSERT INTO tblA
SELECT id, time
FROM dblink('dbname=dbtest', 'SELECT id, time FROM tblB')
AS t(id integer, time integer)
WHERE time > 1000;
TABLE tblA;
id | time
----+------
1 | 5000
2 | 2000
(2 rows)
PostgreSQL has record pseudo-type (only for function's argument or result type), which allows you query data from another (unknown) table.
Edit:
You can make it as prepared statement if you want and it works as well:
PREPARE migrate_data (integer) AS
INSERT INTO tblA
SELECT id, time
FROM dblink('dbname=dbtest', 'SELECT id, time FROM tblB')
AS t(id integer, time integer)
WHERE time > $1;
EXECUTE migrate_data(1000);
-- DEALLOCATE migrate_data;
Edit (yeah, another):
I just saw your revised question (closed as duplicate, or just very similar to this).
If my understanding is correct (postgres has tbla and dbtest has tblb and you want remote insert with local select, not remote select with local insert as above):
psql dbtest
SELECT dblink_exec
(
'dbname=postgres',
'INSERT INTO tbla
SELECT id, time
FROM dblink
(
''dbname=dbtest'',
''SELECT id, time FROM tblb''
)
AS t(id integer, time integer)
WHERE time > 1000;'
);
I don't like that nested dblink, but AFAIK I can't reference to tblB in dblink_exec body. Use LIMIT to specify top 20 rows, but I think you need to sort them using ORDER BY clause first.
If you want insert into specify column:
INSERT INTO table (time)
(SELECT time FROM
dblink('dbname=dbtest', 'SELECT time FROM tblB') AS t(time integer)
WHERE time > 1000
);
This notation (first seen here) looks useful too:
insert into postagem (
resumopostagem,
textopostagem,
dtliberacaopostagem,
idmediaimgpostagem,
idcatolico,
idminisermao,
idtipopostagem
) select
resumominisermao,
textominisermao,
diaminisermao,
idmediaimgminisermao,
idcatolico ,
idminisermao,
1
from
minisermao
You can use dblink to create a view that is resolved in another database. This database may be on another server.
insert into TABLENAMEA (A,B,C,D)
select A::integer,B,C,D from TABLENAMEB
If you are looking for PERFORMANCE, give where condition inside the db link query.
Otherwise it fetch all data from the foreign table and apply the where condition.
INSERT INTO tblA (id,time)
SELECT id, time FROM dblink('dbname=dbname port=5432 host=10.10.90.190 user=postgresuser password=pass123',
'select id, time from tblB where time>'''||1000||'''')
AS t1(id integer, time integer)
I am going to SELECT Databasee_One(10.0.0.10) data from Database_Two (10.0.0.20)
Connect to 10.0.0.20 and create DBLink Extenstion:
CREATE EXTENSION dblink;
Test the connection for Database_One:
SELECT dblink_connect('host=10.0.0.10 user=postgres password=dummy dbname=DB_ONE');
Create foreign data wrapper and server for global authentication:
CREATE FOREIGN DATA WRAPPER postgres VALIDATOR postgresql_fdw_validator;
You can use this server object for cross database queries:
CREATE SERVER dbonepostgres FOREIGN DATA WRAPPER postgres OPTIONS (hostaddr '10.0.0.10', dbname 'DB_ONE');
Mapping of user and server:
CREATE USER MAPPING FOR postgres SERVER dbonepostgres OPTIONS (user 'postgres', password 'dummy');
Test dblink:
SELECT dblink_connect('dbonepostgres');
Import data from 10.0.0.10 into 10.0.0.20
INSERT INTO tableA
SELECT
column1,
,column2,
...
FROM dblink('dbonepostgres', 'SELECT column1, column2, ... from public.tableA')
AS data(column1 DATATYPE, column2 DATATYPE, ...)
;
Here's an alternate solution, without using dblink.
Suppose B represents the source database and A represents the target database:
Then,
Copy table from source DB to target DB:
pg_dump -t <source_table> <source_db> | psql <target_db>
Open psql prompt, connect to target_db, and use a simple insert:
psql
# \c <target_db>;
# INSERT INTO <target_table>(id, x, y) SELECT id, x, y FROM <source_table>;
At the end, delete the copy of source_table that you created in target_table.
# DROP TABLE <source_table>;
How can I find the table creation time in PostgreSQL?
Example: If I created a file I can find the file creation time like that I want to know the table creation time.
I had a look through the pg_* tables, and I couldn't find any creation times in there. It's possible to locate the table files, but then on Linux you can't get file creation time. So I think the answer is that you can only find this information on Windows, using the following steps:
get the database id with select datname, datdba from pg_database;
get the table filenode id with select relname, relfilenode from pg_class;
find the table file and look up its creation time; I think the location should be something like <PostgreSQL folder>/main/base/<database id>/<table filenode id> (not sure what it is on Windows).
You can't - the information isn't recorded anywhere. Looking at the table files won't necessarily give you the right information - there are table operations that will create a new file for you, in which case the date would reset.
I don't think it's possible from within PostgreSQL, but you'll probably find it in the underlying table file's creation time.
Suggested here :
SELECT oid FROM pg_database WHERE datname = 'mydb';
Then (assuming the oid is 12345) :
ls -l $PGDATA/base/12345/PG_VERSION
This workaround assumes that PG_VERSION is the least likely to be modified after the creation.
NB : If PGDATA is not defined, check Where does PostgreSQL store the database?
Check data dir location
SHOW data_directory;
Check For Postgres relation file path :
SELECT pg_relation_filepath('table_name');
you will get the file path of your relation
check for creation time of this file <data-dir>/<relation-file-path>
I tried a different approach to get table creation date which could help for keeping track of dynamically created tables. Suppose you have a table inventory in your database where you manage to save the creation date of the tables.
CREATE TABLE inventory (id SERIAL, tablename CHARACTER VARYING (128), created_at DATE);
Then, when a table you want to keep track of is created it's added in your inventory.
CREATE TABLE temp_table_1 (id SERIAL); -- A dynamic table is created
INSERT INTO inventory VALUES (1, 'temp_table_1', '2020-10-07 10:00:00'); -- We add it into the inventory
Then you could get advantage of pg_tables to run something like this to get existing table creation dates:
SELECT pg_tables.tablename, inventory.created_at
FROM pg_tables
INNER JOIN inventory
ON pg_tables.tablename = inventory.tablename
/*
tablename | created_at
--------------+------------
temp_table_1 | 2020-10-07
*/
For my use-case it is ok because I work with a set of dynamic tables that I need to keep track of.
P.S: Replace inventory in the database with your table name.
I'm trying to follow a different way for obtain this.
Starting from this discussion my solution was:
DROP TABLE IF EXISTS t_create_history CASCADE;
CREATE TABLE t_create_history (
gid serial primary key,
object_type varchar(20),
schema_name varchar(50),
object_identity varchar(200),
creation_date timestamp without time zone
);
--delete event trigger before dropping function
DROP EVENT TRIGGER IF EXISTS t_create_history_trigger;
--create history function
DROP FUNCTION IF EXISTS public.t_create_history_func();
CREATE OR REPLACE FUNCTION t_create_history_func()
RETURNS event_trigger
LANGUAGE plpgsql
AS $$
DECLARE
obj record;
BEGIN
FOR obj IN SELECT * FROM pg_event_trigger_ddl_commands () WHERE command_tag in ('SELECT INTO','CREATE TABLE','CREATE TABLE AS')
LOOP
INSERT INTO public.t_create_history (object_type, schema_name, object_identity, creation_date) SELECT obj.object_type, obj.schema_name, obj.object_identity, now();
END LOOP;
END;
$$;
--ALTER EVENT TRIGGER t_create_history_trigger DISABLE;
--DROP EVENT TRIGGER t_create_history_trigger;
CREATE EVENT TRIGGER t_create_history_trigger ON ddl_command_end
WHEN TAG IN ('SELECT INTO','CREATE TABLE','CREATE TABLE AS')
EXECUTE PROCEDURE t_create_history_func();
In this way you obtain a table that records all the creation tables.
--query
select pslo.stasubtype, pc.relname, pslo.statime
from pg_stat_last_operation pslo
join pg_class pc on(pc.relfilenode = pslo.objid)
and pslo.staactionname = 'CREATE'
Order By pslo.statime desc
will help to accomplish desired results
(tried it on greenplum)
You can get this from pg_stat_last_operation. Here is how to do it:
select * from pg_stat_last_operation where objid = 'table_name'::regclass order by statime;
This table stores following operations:
select distinct staactionname from pg_stat_last_operation;
staactionname
---------------
ALTER
ANALYZE
CREATE
PARTITION
PRIVILEGE
VACUUM
(6 rows)