We have a foreign table that is connecting to Oracle. In Oracle, the columns are:
ticker: VARCHAR2(5)
article_id: NUMBER
In Postgres, we have tried to create the article_id as INTEGER and NUMERIC, but every time we try and query we get this error:
column "article_id" of foreign table "latest_article_id" cannot be converted to or from Oracle data type
How can we create this foreign table so we can query it? The article_id is a number, so is there additional commands we must use?
We are on Postgres 10.10.
CREATE FOREIGN TABLE latest_article_id
(ticker VARCHAR,
article_id NUMERIC)
SERVER usercomm
OPTIONS ( table '(SELECT article_id, ticker
FROM (SELECT a.article_id, t.ticker,
ROW_NUMBER() OVER (PARTITION BY t.ticker
ORDER BY a.publish_date DESC NULLS LAST) AS rnum
FROM tickers t, article_tickers at, articles a
WHERE t.ticker_id = at.ticker_id
AND at.article_id = a.article_id
AND a.status_id = 6
AND a.pull_flag = ''Y'')
WHERE rnum = 1)');
Related
How can I Fetch table data in one query? I have below tables:
Tabel Name: calorieTracker
Creat Table calorieTracker(c_id serial NOT NULL PRIMARY KEY, caloriesConsumption jsonb);
INSERT INTO public."calorieTracker" ("caloriesConsumption")
VALUES ('[{"C_id":"1",,"calorie":88,"date":"19/08/2020"},{"C_id":2,"date":"19/08/2020","calorie":87}]');
Table Name: watertracker
create table watertracker(wt_id serial not null primary key, wt_date varchar, wt_goal float,wt_cid int);
INSERT INTO public.watertracker (wt_id,wt_date,wt_goal,wt_cid)
VALUES (2,'2020-08-19',5.5,2);
What I am looking here I want to write query where date is 19/08/2020(in calorieTracker table and water tracker table) and wt_cid is 2(water tracker table) and c_id is 2(calorieTracker table) then return data.
As you have not mentioned what output you want, so i am assuming you want JSON object from caloriesConsumption which matches the condition mentioned in the question:
based on above assumption try this query:
with cte as (
select
c_id,
jsonb_array_elements("caloriesConsumption") "data"
from "calorieTracker"
)
select
t1.*
from cte t1 inner join watertracker t2
on t2.wt_cid=cast(t1.data->>'c_id' as int)
and t2.wt_date=t1.data->>'date'
if you want the result from watertracker then just replace t1.* with t2.*.
I'm running PostgreSQL 11.8 in a Docker container. I have two databases: website_db and testdb.
website_db has a products table with id, product_name, colour, product_size columns
testdb has a table called users with id, username, password
I'm using website_db and I want to UNION columns from the users table in the testdb database. I can get this to work in MySQL but am struggling with Postgres. Here's my attempt:
SELECT * FROM products WHERE product_name = 'doesntexist' OR 1=1 UNION SELECT null,username,password,null FROM testdb.users;
I get this error back:
ERROR: relation "testdb.users" does not exist
LINE 1: ...1=1 UNION SELECT null,username,password,null FROM testdb.use...
Does anyone know what I have to do to fix my query?
You can do it using dblink:
create database first;
create database second;
\c first;
create table products
(
id serial not null
constraint products_pk
primary key,
product_name varchar(50) not null
);
INSERT INTO public.products (id, product_name) VALUES (1, 'first_db');
\c second;
create table products
(
id serial not null
constraint products_pk
primary key,
product_name varchar(50) not null
);
INSERT INTO public.products (id, product_name) VALUES (1, 'sec_db');
-- dblink -- executes a query in a remote database
create extension dblink;
-- change queries and creds
SELECT id, product_name FROM products
UNION ALL
SELECT * FROM dblink('dbname=first user=root password=root', 'SELECT id, product_name FROM products') AS tb2(id int, product_name text);
Let's say we have the following table that stores id of an observation and its address_id. You can create the table with the following code:
drop table if exists schema.pl_address_cnt;
create table schema.pl_address_cnt (
id serial,
address_id int);
insert into schema.pl_address_cnt(address_id) values
(100), (101), (100), (101), (100), (125), (128), (200), (200), (100);
My task is to count for each id how many other ids (thus -1) have the same address_id. I've come up with a solution that turns out to be quite expensive (explain) on the original dataset. I wonder whether my solution can be somehow optimised.
with tmp_table as (select address_id
, count(distinct id) as id_count
from schema.pl_address_cnt
group by address_id
)
select id
, id_count - 1
from schema.pl_address_cnt as pac
left join tmp_table as tt on tt.address_id=pac.address_id;
You can try to omit the CTE and do a self left join on common address but different ID and then aggregate this.
SELECT pac1.id,
count(pac2.id)
FROM pl_address_cnt pac1
LEFT JOIN pl_address_cnt pac2
ON pac1.address_id = pac2.address_id
AND pac1.id <> pac2.id
GROUP BY pac1.id
ORDER BY pac1.id;
For performance you can try indexes on (address_id, id) and (id).
I am trying to consult a database using pgAdmin3 and I need to join to tables. I am using the following code:
SELECT table1.species, table1.trait, table1.value, table1.units, table2.id, table2.family, table2.latitude, table2.longitude, table2.species as speciescheck
FROM table1 INNER JOIN table2
ON table1.species = table2.species
But I keep running this error:
an out of memory error
So I've tried to insert my result in a new table, as follow:
CREATE TABLE new_table AS
SELECT table1.species, table1.trait, table1.value, table1.units, table2.id, table2.family, table2.latitude, table2.longitude, table2.species as speciescheck
FROM table1 INNER JOIN table2
ON table1.species = table2.species
And still got an error:
ERROR: could not extend file "base/17675/43101.15": No space left on device
SQL state: 53100
Hint: Check free disk space.
I am very very new at this (is the first time I have to deal with PostgreSQL) and I guess I can do something to optimize this query and avoid this type of error. I have no privileges in the database. Can anyone help??
Thanks in advance!
Updated:
Table 1 description
-- Table: table1
-- DROP TABLE table1;
CREATE TABLE table1
(
species character varying(100),
trait character varying(50),
value double precision,
units character varying(50)
)
WITH (
OIDS=FALSE
);
ALTER TABLE table1
OWNER TO postgres;
GRANT ALL ON TABLE table1 TO postgres;
GRANT SELECT ON TABLE table1 TO banco;
-- Index: speciestable1_idx
-- DROP INDEX speciestable1_idx;
CREATE INDEX speciestable1_idx
ON table1
USING btree
(species COLLATE pg_catalog."default");
-- Index: traittype_idx
-- DROP INDEX traittype_idx;
CREATE INDEX traittype_idx
ON table1
USING btree
(trait COLLATE pg_catalog."default");
and table2 as:
-- Table: table2
-- DROP TABLE table2;
CREATE TABLE table2
(
id integer NOT NULL,
family character varying(40),
species character varying(100),
plotarea real,
latitude double precision,
longitude double precision,
source integer,
latlon geometry,
CONSTRAINT table2_pkey PRIMARY KEY (id)
)
WITH (
OIDS=FALSE
);
ALTER TABLE table2
OWNER TO postgres;
GRANT ALL ON TABLE table2 TO postgres;
GRANT SELECT ON TABLE table2 TO banco;
-- Index: latlon_gist
-- DROP INDEX latlon_gist;
CREATE INDEX latlon_gist
ON table2
USING gist
(latlon);
-- Index: species_idx
-- DROP INDEX species_idx;
CREATE INDEX species_idx
ON table2
USING btree
(species COLLATE pg_catalog."default");
You're performing a join between two tables on the column species.
Not sure what's in your data, but if species is a column with significantly fewer values than the number of records (e.g. if species is "elephant", "giraffe" and you're analyzing all animals in Africa), this join will match every elephant with every elephant.
When joining two tables most of the time you try to use a unique or close to unique attribute, like id (not sure what id means in your case, but could be it).
I have a table which references other tables:
CREATE TABLE scratch
(
id SERIAL PRIMARY KEY,
name TEXT NOT NULL,
rep_id INT NOT NULL REFERENCES reps,
term_id INT REFERENCES terms
);
CREATE TABLE reps (
id SERIAL PRIMARY KEY,
rep TEXT NOT NULL UNIQUE
);
CREATE TABLE terms (
id SERIAL PRIMARY KEY,
terms TEXT NOT NULL UNIQUE
);
I wish to add a new record to scratch given the name, the rep and the terms values, i.e. I have neither corresponding rep_id nor term_id.
Right now the only idea that I have is:
insert into scratch (name, rep_id, term_id)
values ('aaa', (select id from reps where rep='Dracula' limit 1), (select id from terms where terms='prepaid' limit 1));
My problem is this. I am trying to use the parameterized query API (from node using the node-postgres package), where an insert query looks like this:
insert into scratch (name, rep_id, term_id) values ($1, $2, $3);
and then an array of values for $1, $2 and $3 is passed as a separate argument. At the end, when I am comfortable with the parameterized queries the idea is to promote them to prepared statements to utilize the most efficient and safest way to query the database.
However, I am puzzled how can I do this with my example, where different tables have to be subqueried.
P.S. I am using PostgreSQL 9.2 and have no problem with a PostgreSQL specific solution.
EDIT 1
C:\Users\markk>psql -U postgres
psql (9.2.4)
WARNING: Console code page (437) differs from Windows code page (1252)
8-bit characters might not work correctly. See psql reference
page "Notes for Windows users" for details.
Type "help" for help.
postgres=# \c dummy
WARNING: Console code page (437) differs from Windows code page (1252)
8-bit characters might not work correctly. See psql reference
page "Notes for Windows users" for details.
You are now connected to database "dummy" as user "postgres".
dummy=# DROP TABLE scratch;
DROP TABLE
dummy=# CREATE TABLE scratch
dummy-# (
dummy(# id SERIAL NOT NULL PRIMARY KEY,
dummy(# name text NOT NULL UNIQUE,
dummy(# rep_id integer NOT NULL,
dummy(# term_id integer
dummy(# );
NOTICE: CREATE TABLE will create implicit sequence "scratch_id_seq" for serial column "scratch.id"
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "scratch_pkey" for table "scratch"
NOTICE: CREATE TABLE / UNIQUE will create implicit index "scratch_name_key" for table "scratch"
CREATE TABLE
dummy=# DEALLOCATE insert_scratch;
ERROR: prepared statement "insert_scratch" does not exist
dummy=# PREPARE insert_scratch (text, text, text) AS
dummy-# INSERT INTO scratch (name, rep_id, term_id)
dummy-# SELECT $1, r.id, t.id
dummy-# FROM reps r, terms t
dummy-# WHERE r.rep = $2 AND t.terms = $3
dummy-# RETURNING id, name, $2 rep, $3 terms;
PREPARE
dummy=# DEALLOCATE insert_scratch2;
ERROR: prepared statement "insert_scratch2" does not exist
dummy=# PREPARE insert_scratch2 (text, text, text) AS
dummy-# INSERT INTO scratch (name, rep_id, term_id)
dummy-# VALUES ($1, (SELECT id FROM reps WHERE rep=$2 LIMIT 1), (SELECT id FROM terms WHERE terms=$3 LIMIT 1))
dummy-# RETURNING id, name, $2 rep, $3 terms;
PREPARE
dummy=# EXECUTE insert_scratch ('abc', 'Snowhite', '');
id | name | rep | terms
----+------+-----+-------
(0 rows)
INSERT 0 0
dummy=# EXECUTE insert_scratch2 ('abc', 'Snowhite', '');
id | name | rep | terms
----+------+----------+-------
1 | abc | Snowhite |
(1 row)
INSERT 0 1
dummy=# EXECUTE insert_scratch ('abcd', 'Snowhite', '30 days');
id | name | rep | terms
----+------+----------+---------
2 | abcd | Snowhite | 30 days
(1 row)
INSERT 0 1
dummy=# EXECUTE insert_scratch2 ('abcd2', 'Snowhite', '30 days');
id | name | rep | terms
----+-------+----------+---------
3 | abcd2 | Snowhite | 30 days
(1 row)
INSERT 0 1
dummy=#
EDIT 2
We can utilize the fact that rep_id is required, even though terms_id is optional and use the following version of INSERT-SELECT:
PREPARE insert_scratch (text, text, text) AS
INSERT INTO scratch (name, rep_id, term_id)
SELECT $1, r.id, t.id
FROM reps r
LEFT JOIN terms t ON t.terms = $3
WHERE r.rep = $2
RETURNING id, name, $2 rep, $3 terms;
This version, however, has two problems:
No distinction is made between a missing terms value (i.e. '') and an invalid terms value (i.e. a non empty value missing from the terms table entirely). Both are treated as missing terms. (But the INSERT with two subqueries suffers from the same problem)
The version depends on the fact that the rep is required. But what if rep_id was optional too?
EDIT 3
Found the solution for the item 2 - eliminating dependency on rep being required. Plus using the WHERE statement has the problem that the sql does not fail if the rep is invalid - it just inserts 0 rows, whereas I want to fail explicitly in this case. My solution is simply using a dummy one row CTE:
PREPARE insert_scratch (text, text, text) AS
WITH stub(x) AS (VALUES (0))
INSERT INTO scratch (name, rep_id, term_id)
SELECT $1, r.id, t.id
FROM stub
LEFT JOIN terms t ON t.terms = $3
LEFT JOIN reps r ON r.rep = $2
RETURNING id, name, rep_id, term_id;
If rep is missing or invalid, this sql will try to insert NULL into the rep_id field and since the field is NOT NULL an error would be raised - precisely what I need. And if further I decide to make rep optional - no problem, the same SQL works for that too.
INSERT into scratch (name, rep_id, term_id)
SELECT 'aaa'
, r.id
, t.id
FROM reps r , terms t -- essentially a cross join
WHERE r.rep = 'Dracula'
AND t.terms = 'prepaid'
;
Notes:
You don't need the ugly LIMITs, since r.rep and t.terms are unique (candidate keys)
you could replace the FROM a, b by a FROM a CROSS JOIN b
the scratch table will probably need an UNIQUE constraint on (rep_id, term_it) (the nullability of term_id is questionable)
UPDATE: the same as prepared query as found in the Documentation
PREPARE hoppa (text, text,text) AS
INSERT into scratch (name, rep_id, term_id)
SELECT $1 , r.id , t.id
FROM reps r , terms t -- essentially a cross join
WHERE r.rep = $2
AND t.terms = $3
;
EXECUTE hoppa ('bbb', 'Dracula' , 'prepaid' );
SELECT * FROM scratch;
UPDATE2: test data
DROP SCHEMA tmp CASCADE;
CREATE SCHEMA tmp ;
SET search_path=tmp;
CREATE TABLE reps ( id SERIAL PRIMARY KEY, rep TEXT NOT NULL UNIQUE);
CREATE TABLE terms ( id SERIAL PRIMARY KEY, terms TEXT NOT NULL UNIQUE);
CREATE TABLE scratch ( id SERIAL PRIMARY KEY, name TEXT NOT NULL, rep_id INT NOT NULL REFERENCES reps, term_id INT REFERENCES terms);
INSERT INTO reps(rep) VALUES( 'Dracula' );
INSERT INTO terms(terms) VALUES( 'prepaid' );
Results:
NOTICE: drop cascades to 3 other objects
DETAIL: drop cascades to table tmp.reps
drop cascades to table tmp.terms
drop cascades to table tmp.scratch
DROP SCHEMA
CREATE SCHEMA
SET
CREATE TABLE
CREATE TABLE
CREATE TABLE
INSERT 0 1
INSERT 0 1
INSERT 0 1
PREPARE
INSERT 0 1
id | name | rep_id | term_id
----+------+--------+---------
1 | aaa | 1 | 1
2 | bbb | 1 | 1
(2 rows)