The below query errors on ERROR: column "page" does not exist
If I replace (j) and (page) with hardcoded values; then the query will run.
My goal is to walk through records_to_update table; and then update a batch of records at a time.
DO $$
DECLARE
page int := 50;
BEGIN
FOR j IN 0..(select count(*) from records_to_update) BY page LOOP
with subset_to_update as (
select
* from records_to_update
order by target_class_id, main_type_id, source_class_id
offset (j)
limit (page)
) update large_table_to_update
set to_update_class_id = stu.target_class_id
from
subset_to_update stu
where
large_table_to_update.annotation_class_id = stu.source_class_id;
COMMIT;
END LOOP;
END; $$;
Related
I'm looking for a PostgreSQL equivalent of the image below. I have a script to batch insert multiple tables, the idea is to declare some variables to count how many of each have been inserted when executing.
So far I have this, however there's no straightforward way for ##ROW_COUNT:
BEGIN TRANSACTION;
DO $$
DECLARE
EmailModulesTotal integer := 0;
DependenciesTotal integer := 0;
ModuleTypesTotal integer := 0;
ModuleSectionsTotal integer := 0;
BEGIN
-- inserts go here
RAISE NOTICE 'Total Inserted/Updated Email Modules: %
Total Inserted Dependencies: %
Total Inserted Module Types: %
Total Inserted Module Sections: %',
EmailModulesTotal,
DependenciesTotal,
ModuleTypesTotal,
ModuleSectionsTotal
END $$;
COMMIT TRANSACTION;
In PL/pgSQL you can access the number of affected (i.e. inserted in your case) rows using get diagnostics. Here is an illustration.
create temporary table t (id serial, txt text);
do language plpgsql
$$
declare
counter integer;
begin
insert into t(txt) values ('One'), ('Two'), ('Three');
get diagnostics counter = row_count;
raise notice 'Inserted % rows', counter;
end;
$$;
The result is Inserted 3 rows
Another way in plain SQL is to use a data modifying CTE:
with cte as
(
insert into t(txt) values ('One'), ('Two'), ('Three')
returning 1
)
select count(*) from cte;
Whichever suits you better.
EDIT: I am creating a new question as per suggestion from sticky bit.
I have a query with CTEs to output results for several values (1 to 12). Below is a simplified example. Running it I got the following error:
ERROR: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgSQL function inline_code_block line 8 at SQL statement
I can't output the result of Select in a table. How can I solve this problem?
DO $$
DECLARE r integer;
BEGIN
r := 1;
WHILE r <= 2
LOOP
r := r + 1;
WITH params AS (
SELECT r AS rownumber
),
time AS (
SELECT id
FROM params, analysis
ORDER BY date DESC
LIMIT 1
OFFSET (SELECT rownumber - 1 from params)
)
SELECT * FROM time;
END LOOP;
END; $$;
An example of what I mentioned in my comment:
DO $$
DECLARE
r integer;
int_var integer;
BEGIN
r := 1;
WHILE r <= 12 LOOP
WITH params AS (
SELECT r AS rownumber
),
time AS (
SELECT id
FROM params, analysis
ORDER BY date DESC
LIMIT 1
OFFSET (SELECT rownumber - 1 from params)
)
SELECT INTO int_var id FROM time;
RAISE NOTICE 'id: %', int_var;
r := r + 1;
END LOOP;
END; $$;
You can't RETURN a value from a DO function, but you can RAISE NOTICE a value as above. The SELECT INTO will eliminate the error as you are giving the SELECT a destination(the int_var) for its output. NOTE: SELECT INTO inside plpgsql is different then the same command outside. Outside it is equivalent to CREATE TABLE AS.
create table my_table(x int, y int);
create function get_rows()
returns table (lie my_table) as $$
begin
-- 1 First try
--select * from my_table where x < 0;
-- 2 If empty then try
--select * from my_table where y < 0;
end; $$
language plpgsql;
How to implement a function that selects rows based on condition 1, but if such rows don't exists then select based on condition 2. If nether conditions can be satisfied then return an empty table.
You can us "IF EXISTS" to test the first condition. Then depending on the result use RETURN Query for the appropriate select;
create or replace function get_rows()
returns table (lie my_table)
language plpgsql
as $$
begin
-- 1 First try
if exists (select null from my_table where x < 0)
then
return query
select * from my_table
where x < 0;
-- 2 If empty then try
else
return query
select * from my_table
where y < 0;
end if;
end; $$;
I am using Postgresql11 and a function that works well in a single run fails when I add a LOOP statement with
"ERROR: query has no destination for result data HINT: If you want to
discard the results of a SELECT, use PERFORM instead."
The function has VOID as return value, selects data from a source table into a temp table, calculates some data and inserts the result into a target table. The temp table is then dropped and the function ends. I would like to repeat this procedure in defined intervals and have included a LOOP statement. With LOOP it does not insert into the target table and does not actually loop at all.
create function transfer_cs_regular_loop(trading_pair character varying) returns void
language plpgsql
as
$$
DECLARE
first_open decimal;
first_price decimal;
last_close decimal;
last_price decimal;
highest_price decimal;
lowest_price decimal;
trade_volume decimal;
n_trades int;
start_time bigint;
last_entry bigint;
counter int := 0;
time_frame int := 10;
BEGIN
WHILE counter < 100 LOOP
SELECT max(token_trades.trade_time) INTO last_entry FROM token_trades WHERE token_trades.trade_symbol = trading_pair;
RAISE NOTICE 'Latest Entry: %', last_entry;
start_time = last_entry - (60 * 1000);
RAISE NOTICE 'Start Time: %', start_time;
CREATE TEMP TABLE temp_table AS
SELECT * FROM token_trades where trade_symbol = trading_pair and trade_time > start_time;
SELECT temp_table.trade_time,temp_table.trade_price INTO first_open, first_price FROM temp_table ORDER BY temp_table.trade_time ASC FETCH FIRST 1 ROW ONLY;
SELECT temp_table.trade_time,temp_table.trade_price INTO last_close, last_price FROM temp_table ORDER BY temp_table.trade_time DESC FETCH FIRST 1 ROW ONLY;
SELECT max(temp_table.trade_price) INTO highest_price FROM temp_table;
SELECT min(temp_table.trade_price) INTO lowest_price FROM temp_table;
SELECT INTO trade_volume sum(temp_table.trade_quantity) FROM temp_table;
SELECT INTO n_trades count(*) FROM temp_table;
INSERT INTO candlestick_data_5min_test(open, high, low, close, open_time, close_time, volume, number_trades, trading_pair) VALUES (first_price, highest_price, lowest_price, last_price, first_open, last_close, trade_volume, n_trades, trading_pair);
DROP TABLE temp_table;
counter := counter + 1;
SELECT pg_sleep(time_frame);
RAISE NOTICE '**************************Counter: %', counter;
END LOOP;
END;
$$;
The error refers to the last SELECT statement in the function. If there is a SELECT without INTO it will always return results. When there's no LOOP this result will be used as the return value of the function (even if it is void).
When you add a LOOP there can't be any SELECT without INTO inside the loop because a single return value would be needed and now there will be many. In this case you need to use PERFORM which does exactly the same thing as a SELECT but discards the results.
Therefore change the last SELECT into a PERFORM and the error will go away:
PERFORM pg_sleep(time_frame);
I am trying to write a plpgsql function that loops through a table. On each loop, it pulls a row from the table, stores it in a record, then uses that record in the join clause of a query. Here is my code:
CREATE OR REPLACE FUNCTION "testfncjh2" () RETURNS int
IMMUTABLE
SECURITY DEFINER
AS $dbvis$
DECLARE
counter int;
tablesize int;
rec1 record;
tablename text;
rec2 record;
BEGIN
counter = 0;
for rec1 in SELECT * FROM poilocations_sridconv loop
raise notice 'here';
execute $$ select count(*) from $$||rec1||$$ $$ into tablesize;
while counter < tablesize loop
counter = counter + 1;
raise notice 'hi';
execute $$ select count(*) from cities_sridconv $$ into tablesize;
end loop;
end loop;
return counter;
END;
$dbvis$ LANGUAGE plpgsql;
Each time I run this, I get the following error:
ERROR: could not find array type for data type record
Is there a way to use the row as a table in the query within the nested loops?
My end goal is to build a function that loops through a table, pulling a row from that table on each loop. In each loop, a number COUNTER is computed using the row, then a query is executed depending on the row and COUNTER. Knowing that this code is currently very flawed, I am posting it below to give an idea of what I am trying to do:
CREATE OR REPLACE FUNCTION "testfncjh" () RETURNS void
IMMUTABLE
SECURITY DEFINER
AS $dbvis$
DECLARE
counter int;
tablesize int;
rec1 record;
tablename text;
rec2 record;
BEGIN
for rec1 in SELECT * FROM poilocations_sridconv loop
counter = 0;
execute $$ select count(*)
from $$||rec1||$$ a
join
cities_srid_conv b
on right(a.geom_wgs_pois,$$||counter||$$) = right(b.geom_wgs_pois,$$||counter||$$) $$ into tablesize;
raise notice 'got through first execute';
while tablesize = 0 loop
counter = counter + 1;
execute $$ select count(*)
from '||rec1||' a
join
cities_srid_conv b
on right(a.geom_wgs_pois,'||counter||') = right(b.geom_wgs_pois,'||counter||') $$ into tablesize;
raise notice 'hi';
end loop;
EXECUTE
'select
poiname,
name as cityname,
postgis.ST_Distance(postgis.ST_GeomFromText(''POINT(poilat poilong)''),
postgis.ST_GeomFromText(''POINT(citylat citylong)'')
) as distance
from (select a.poiname,
a.latitude::text as poilat,
a.longitude::text as poilong,
b.geonameid,
b.name,
b.latitude as citylat,
b.longitude as citylong
from '||rec1||' a
join cities_srid_conv b
on right(a.geom_wgs_pois,'||counter||') = right(b.geom_wgs_pois,'||counter||'))
) x
order by distance
limit 1'
poi_cities_match (poiname, cityname, distance); ------SQL STATEMENT TO INSERT CLOSEST CITY TO TABLE POI_CITIES_MATCH
end loop;
END;
$dbvis$ LANGUAGE plpgsql;
I am running on a PostgreSQL 8.2.15 database.
Also, sorry for reposting. I had to remove some data from the original.
I think you should be able to use composite types for what you want. I simplified your top example and used composite types in the following way.
CREATE OR REPLACE FUNCTION "testfncjh2" () RETURNS int
IMMUTABLE
SECURITY DEFINER
AS $dbvis$
DECLARE
counter int;
tablesize int;
rec1 poilocations_sridconv;
tablename text;
rec2 record;
BEGIN
counter = 0;
for rec1 in SELECT * FROM poilocations_sridconv loop
raise notice 'here';
select count(*) FROM (select (rec1).*)theRecord into counter;
end loop;
return counter;
END;
$dbvis$ LANGUAGE plpgsql;
The main changes being the rec1 poilocations_sridconv; line and using (select (rec1).*)
Hope it helps.
EDIT: I should note that the function is not doing the same thing as it does in the question above. This is just as an example of how you could use a record as a table in a query.
You have a few issues with your code (apart, perhaps, from your logic).
Foremost, you should not use a record as a table source in a JOIN. Instead, filter the second table for rows that match some field from the record.
Second, you should use the format() function instead of assembling strings with the || operator. But you can't because you are using the before-prehistoric version 8.2. This is from the cave-painting era (yes, it's that bad). UPGRADE!
Thirdly, don't over-complicate your queries. The sub-query is not necessary here.
Put together, the second dynamic query from your real code would reduce to this:
EXECUTE format(
'SELECT b.name,
postgis.ST_Distance(postgis.ST_SetSRID(postgis.ST_MakePoint(%1$I.longitude, %1$I.latitude), 4326),
postgis.ST_SetSRID(postgis.ST_MakePoint(b.longitude, b.latitude), 4326))
FROM cities_srid_conv b
WHERE right(%1$I.geom_wgs_pois, %2$L) = right(b.geom_wgs_pois, %2$L)
ORDER BY distance
LIMIT 1', rec1, counter) INTO cityname, distance;
poi_cities_match (rec1.poiname, cityname, distance); ------SQL STATEMENT TO INSERT CLOSEST CITY TO TABLE POI_CITIES_MATCH
Here %1$I refers to the first parameter after the string, which is an idenifier: rec1; %2$L is the second parameter, being a literal value: counter. I leave it to yourself to re-work this to a pre-8.4 string concatenation. The results from the query are stored in a few additional variables which you can then use in the following function call.
Lastly, you had longitude and latitude reversed. In PostGIS longitude always comes first.