I have a job table. I have an industries table. Jobs and industries have a many to many relationship via a join table called industriesjobs. Both tables have uuid is their primary key. My question is two fold. Firstly is it feasible to write two functions to insert data like this? If this is feasible then my second question is how do I express an array of the uuid column type. I'm unsure of the syntax.
CREATE OR REPLACE FUNCTION linkJobToIndustries(jobId uuid, industiresId uuid[]) RETURNS void AS $$
DECLARE
industryId uuid[];
BEGIN
FOREACH industryId SLICE 1 IN ARRAY industriesId LOOP
INSERT INTO industriesjobs (industry_id, job_id) VALUES (industryId, jobId);
END LOOP;
RETURN;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION insertJobWithIndistries(orginsation varchar, title varchar, addressId uuid, industryIds uuid[]) RETURNS uuid AS $$
DECLARE
jobId uuid;
BEGIN
INSERT INTO jobs ("organisation", "title", "address_id") VALUES (orginsation, title, addressId) RETURNING id INTO jobId;
SELECT JobbaLinkJobToIndustries(jobId, industryIds);
END;
$$ LANGUAGE plpgsql;
SELECT jobId FROM insertJobWithIndistries(
'Acme Inc'::varchar,
'Bomb Tester'::varchar,
'0030cfb3-1a03-4c5a-9afa-6b69376abe2e',
{ 19c2e0ee-acd5-48b2-9fac-077ad4d49b19, 21f8ffb7-e155-4c8f-acf0-9e991325784, 28c18acd-99ba-46ac-a2dc-59ce952eecf2 }
);
Thanks in advance.
Key to a solution are the function unnest() to (per documentation):
expand an array to a set of rows
And a data-modifying CTE.
A simple query does the job:
WITH ins_job AS (
INSERT INTO jobs (organisation, title, address_id)
SELECT 'Acme Inc', 'Bomb Tester', '0030cfb3-1a03-4c5a-9afa-6b69376abe2e' -- job-data here
RETURNING id
)
INSERT INTO industriesjobs (industry_id, job_id)
SELECT indid, id
FROM ins_job i -- that's a single row, so a CROSS JOIN is OK
, unnest('{19c2e0ee-acd5-48b2-9fac-077ad4d49b19
, 21f8ffb7-e155-4c8f-acf0-9e9913257845
, 28c18acd-99ba-46ac-a2dc-59ce952eecf2}'::uuid[]) indid; -- industry IDs here
Also demonstrating proper syntax for an array of uuid. (White space between elements and separators is irrelevant while not inside double-quotes.)
One of your UUIDs was one character short:
21f8ffb7-e155-4c8f-acf0-9e991325784
Must be something like:
21f8ffb7-e155-4c8f-acf0-9e9913257845 -- one more character
If you need functions, you do that, too:
CREATE OR REPLACE FUNCTION link_job_to_industries(_jobid uuid, _indids uuid[])
RETURNS void AS
$func$
INSERT INTO industriesjobs (industry_id, job_id)
SELECT _indid, _jobid
FROM unnest(_indids) _indid;
$func$ LANGUAGE sql;
Etc.
Related:
Insert data in 3 tables at a time using Postgres
How to insert multiple rows using a function in PostgreSQL
Related
I am building a function on postgresql, basically send one id from one table then re-build the insert statement of that row and insert it as string column from another table.
I have this table, in insert_query I want to store the insert statement of one row, with his variables:
create table get_insert (tabname varchar(30), insert_query varchar(5000));
I want to store something like this on insert_query column:
Insert into baseball_table (code, name) select '01','Robet';
Currently my function is storing just this, which doesn't work since I need to store the real values:
INSERT INTO baseball_table(code,name) SELECT code,name FROM baseball_table WHERE id=1;
This is my function:
CREATE OR REPLACE FUNCTION get_values(
_id character varying
)
RETURNS boolean
LANGUAGE 'plpgsql'
VOLATILE PARALLEL UNSAFE
AS $function$
DECLARE v_id integer;
DECLARE sql_brand varchar;
BEGIN
sql_query'INSERT INTO baseball_table(code,name) SELECT code,name FROM core.brand WHERE id=' || v_id ||'
';
INSERT INTO core.clone_brand (tabname, insert_query)VALUES ('brand',sql_query);
RETURN true;
END;
$function$;
Which is the best way to get the real values without making variables of each column?
Regards
I want to get the way to get the real values without making variables of each column.
I'm trying to dynamically generate text values, insert them into a table while checking their uniqueness, and return such values from a function. I managed to do #1 and #2, but I can't find a way for the function to return the generated values. The last try is this one. Returning a table from the function and creating a temp table in the body of the function that's used in the Return clause.
CREATE OR REPLACE FUNCTION add_unique_codes(
number_of_codes_to_generate integer,
code_length integer,
effective_date date,
expiry_date date)
RETURNS TABLE(generated_code text)
LANGUAGE 'plpgsql'
AS $BODY$
DECLARE
random_code text := '';
BEGIN
CREATE TEMPORARY TABLE generated_codes(cd text) ON COMMIT DROP;
FOR i IN 1..number_of_codes_to_generate LOOP
random_code = unique_random_code(code_length, 'p_codes', 'id');
INSERT INTO p_codes (code, type, effective_date, expiry_date)
VALUES (random_code, 'B', effective_date, expiry_date);
INSERT INTO generated_codes VALUES (random_code);
END LOOP;
RETURN QUERY SELECT cd FROM generated_codes;
END;
$BODY$;
As I said, the function unique_random_code is working fine and I also see the new "codes" inserted in the p_codes table. The only issue is the function doesn't return the set of "codes" back.
Thank you
No need for a temporary table or a slow PL/pgSQL FOR loop. You can use generate_series() to generate the number of rows, and the returning option of the INSERT statement to return those rows:
CREATE OR REPLACE FUNCTION add_unique_codes(
number_of_codes_to_generate integer,
code_length integer,
effective_date date,
expiry_date date)
RETURNS TABLE(generated_code text)
LANGUAGE sql
AS
$BODY$
INSERT INTO p_codes (code, type, effective_date, expiry_date)
select unique_random_code(code_length, 'p_codes', 'id'), 'B', effective_date, expiry_date
from generate_series(1, number_of_codes_to_generate)
returning code;
$BODY$;
I'd like to run the create_company_maybe_race_condition() function below, but think it might create a race condition if plpgsql functions don't run sequentially. I'm on Postgres 12.
My real world scenario is that I have Row Level Security turned on for all of my tables. The RLS check relies on an access control list in a permissions table. When I add a row to a table, I can't use the RETURNING clause since there isn't a row in the permissions table yet that'll allow the user to read the object.
CREATE TABLE companies (
PRIMARY KEY(company_id),
company_id uuid,
);
CREATE TABLE departments (
PRIMARY KEY (department_id),
department_id uuid DEFAULT gen_random_uuid(),
name text,
company_id uuid REFERENCES companies
);
/**********/
CREATE FUNCTION create_company_maybe_race_condition ()
RETURNS void AS $$
DECLARE
v_company_id := gen_random_uuid();
BEGIN
INSERT INTO companies (company_id)
VALUES (v_company_id);
INSERT INTO departments (company_id, name)
VALUES (v_company_id, 'My Department'); -- Postgres doesn't know that it depends on companies
END;
$$ LANGUAGE plpgsql;
/**********/
CREATE FUNCTION create_company_no_race_condition ()
RETURNS void AS $$
DECLARE
v_company_id uuid;
BEGIN
INSERT INTO companies (company_id)
VALUES (DEFAULT)
RETURN company_id INTO v_company_id;
INSERT INTO departments (company_id, name)
VALUES (v_company_id, 'My Department');
END;
$$ LANGUAGE plpgsql;
New to Stored Procedures , have a requirement where I need to execute multiple queries inside stored procedure and return results. I would like to know whether this is possible or not ..
Ex :
Query 1 returns a list of userid ..
Select userid from user where username = ?
For each userid from the above query , I need to execute three different queries like
Query 2 select session_details from session where userid = ?
Query 3 select location from location where userid = ?
The return value should be a collection of , session_details and location.
Is this possible,can you provide some hints?
You can loop through query results like so:
FOR id IN Select userid from user where username = ?
LOOP
...
END LOOP;
As #Fahad Anjum says in his comment, its better if you can do it in a query. But if that's not posible, you have tree posibilities to achive what you want.
SETOF
TABLE
refcursor
1. SETOF
You can return a set of values. The set can be an existing table, a temporal table, or a TYPE you define.
TYPE example:
-- In your case the type could be (userid integer, session integer, location text)
CREATE TYPE tester AS (id integer);
-- The pl returns a SETOF the created type.
CREATE OR REPLACE FUNCTION test() RETURNS SETOF tester
AS $$
BEGIN
RETURN QUERY SELECT generate_series(1, 3) as id;
END;
$$ LANGUAGE plpgsql
-- Then, you get the set by selecting the PL as if it were a table.
SELECT * FROM test();
Table and Temp Table examples:
-- Create a temporal table o a regular table:
CREATE TEMP TABLE test_table(id integer);
-- or CREATE TABLE test_table(id integer);
-- or use an existing table in your schema(s);
-- The pl returns a SETOF the table you need
CREATE OR REPLACE FUNCTION test() RETURNS SETOF test_table
AS $$
BEGIN
RETURN QUERY SELECT generate_series(1, 3) as id;
END;
$$ LANGUAGE plpgsql
-- Then, you get the set by selecting the PL as if it were a table.
SELECT * FROM test();
-- NOTE: Since you are only returning a SETOF the table,
-- you don't insert any data into the table.
-- So, if you select the 'temp' table you won't see any changes.
SELECT * FROM test_table
2. TABLE
A PL can return a table, it would be similar to create a temporal table and then return a SETOF, but, in this case you declare de 'temp' table on the 'returns' sentence of the PL.
-- Next to TABLE you define the columns of the table the PL will return
CREATE OR REPLACE FUNCTION test() RETURNS TABLE (id integer)
AS $$
BEGIN
RETURN QUERY SELECT generate_series(1, 3) as id;
END;
$$ LANGUAGE plpgsql
-- As the other examples, you select the PL to get the data.
SELECT * FROM test();
3. refcursor
This one is the more complex solution. You return a cursor, not the actual data. If you need 'dynamic' values for your returning set, this is the solution.
But since you need static data, you won't need this option.
The use of any of these ways depends on any specific case, if you use regularly the userid,session,location in different ways and PLs, it would be better to Use the SETOF with a type.
If you have a table that has the userid,session,location columns, it's better to return a SETOF table.
If you just use the userid,session,location for one case, then it would be better to use a 'RETURNS TABLE' approach.
If you need to return a dynamic set you would have to use cursors... but that solution is really more advanced.
Based solely on your example, here's probably the easiest way to do it:
CREATE FUNCTION my_func(user_id INTEGER)
RETURNS TABLE (userid INTEGER, session INTEGER, location TEXT) AS
$$
SELECT u.userid, s.session, l.location
FROM -- etc... your query here
$$
LANGUAGE SQL STABLE;
Addressing comment:
That's a bit of a different question. One question is how to return multiple records containing multiple fields in a stored procedure. One way is as above.
The other question is how to write a query that gets data from multiple tables. Again, there are many ways to do it. One way is (again, based on my interpretation of your requirements in the examples):
SELECT userid
, ARRAY_AGG(SELECT session_details FROM session s WHERE s.userid = u.userid)
, ARRAY_AGG(SELECT l.location FROM location l WHERE l.userid = u.userid)
FROM user u
WHERE username = user_name
This will return one record containing the user_id, an array of session_details for that user, and an array of locations for that user.
Then the function can be changed to:
CREATE FUNCTION my_func(user_name TEXT, OUT userid INTEGER, OUT session_details TEXT[], OUT locations TEXT[])
AS $$
SELECT userid
, ARRAY(SELECT session_details FROM session s WHERE s.userid = u.userid)
, ARRAY(SELECT l.location FROM location l WHERE l.userid = u.userid)
FROM user u
WHERE username = user_name;
$$ LANGUAGE SQL STABLE;
I implemented this function in my Postgres database: http://www.cureffi.org/2013/03/19/automatically-creating-pivot-table-column-names-in-postgresql/
Here's the function:
create or replace function xtab (tablename varchar, rowc varchar, colc varchar, cellc varchar, celldatatype varchar) returns varchar language plpgsql as $$
declare
dynsql1 varchar;
dynsql2 varchar;
columnlist varchar;
begin
-- 1. retrieve list of column names.
dynsql1 = 'select string_agg(distinct '||colc||'||'' '||celldatatype||''','','' order by '||colc||'||'' '||celldatatype||''') from '||tablename||';';
execute dynsql1 into columnlist;
-- 2. set up the crosstab query
dynsql2 = 'select * from crosstab (
''select '||rowc||','||colc||','||cellc||' from '||tablename||' group by 1,2 order by 1,2'',
''select distinct '||colc||' from '||tablename||' order by 1''
)
as ct (
'||rowc||' varchar,'||columnlist||'
);';
return dynsql2;
end
$$;
So now I can call the function:
select xtab('globalpayments','month','currency','(sum(total_fees)/sum(txn_amount)*100)::decimal(48,2)','text');
Which returns (because the return type of the function is varchar):
select * from crosstab (
'select month,currency,(sum(total_fees)/sum(txn_amount)*100)::decimal(48,2)
from globalpayments
group by 1,2
order by 1,2'
, 'select distinct currency
from globalpayments
order by 1'
) as ct ( month varchar,CAD text,EUR text,GBP text,USD text );
How can I get this function to not only generate the code for the dynamic crosstab, but also execute the result? I.e., the result when I manually copy/paste/execute is this. But I want it to execute without that extra step: the function shall assemble the dynamic query and execute it:
Edit 1
This function comes close, but I need it to return more than just the first column of the first record
Taken from: Are there any way to execute a query inside the string value (like eval) in PostgreSQL?
create or replace function eval( sql text ) returns text as $$
declare
as_txt text;
begin
if sql is null then return null ; end if ;
execute sql into as_txt ;
return as_txt ;
end;
$$ language plpgsql
usage: select * from eval($$select * from analytics limit 1$$)
However it just returns the first column of the first record :
eval
----
2015
when the actual result looks like this:
Year, Month, Date, TPV_USD
---- ----- ------ --------
2016, 3, 2016-03-31, 100000
What you ask for is impossible. SQL is a strictly typed language. PostgreSQL functions need to declare a return type (RETURNS ..) at the time of creation.
A limited way around this is with polymorphic functions. If you can provide the return type at the time of the function call. But that's not evident from your question.
Refactor a PL/pgSQL function to return the output of various SELECT queries
You can return a completely dynamic result with anonymous records. But then you are required to provide a column definition list with every call. And how do you know about the returned columns? Catch 22.
There are various workarounds, depending on what you need or can work with. Since all your data columns seem to share the same data type, I suggest to return an array: text[]. Or you could return a document type like hstore or json. Related:
Dynamic alternative to pivot with CASE and GROUP BY
Dynamically convert hstore keys into columns for an unknown set of keys
But it might be simpler to just use two calls: 1: Let Postgres build the query. 2: Execute and retrieve returned rows.
Selecting multiple max() values using a single SQL statement
I would not use the function from Eric Minikel as presented in your question at all. It is not safe against SQL injection by way of maliciously malformed identifiers. Use format() to build query strings unless you are running an outdated version older than Postgres 9.1.
A shorter and cleaner implementation could look like this:
CREATE OR REPLACE FUNCTION xtab(_tbl regclass, _row text, _cat text
, _expr text -- still vulnerable to SQL injection!
, _type regtype)
RETURNS text
LANGUAGE plpgsql AS
$func$
DECLARE
_cat_list text;
_col_list text;
BEGIN
-- generate categories for xtab param and col definition list
EXECUTE format(
$$SELECT string_agg(quote_literal(x.cat), '), (')
, string_agg(quote_ident (x.cat), %L)
FROM (SELECT DISTINCT %I AS cat FROM %s ORDER BY 1) x$$
, ' ' || _type || ', ', _cat, _tbl)
INTO _cat_list, _col_list;
-- generate query string
RETURN format(
'SELECT * FROM crosstab(
$q$SELECT %I, %I, %s
FROM %I
GROUP BY 1, 2 -- only works if the 3rd column is an aggregate expression
ORDER BY 1, 2$q$
, $c$VALUES (%5$s)$c$
) ct(%1$I text, %6$s %7$s)'
, _row, _cat, _expr -- expr must be an aggregate expression!
, _tbl, _cat_list, _col_list, _type);
END
$func$;
Same function call as your original version. The function crosstab() is provided by the additional module tablefunc which has to be installed. Basics:
PostgreSQL Crosstab Query
This handles column and table names safely. Note the use of object identifier types regclass and regtype. Also works for schema-qualified names.
Table name as a PostgreSQL function parameter
However, it is not completely safe while you pass a string to be executed as expression (_expr - cellc in your original query). This kind of input is inherently unsafe against SQL injection and should never be exposed to the general public.
SQL injection in Postgres functions vs prepared queries
Scans the table only once for both lists of categories and should be a bit faster.
Still can't return completely dynamic row types since that's strictly not possible.
Not quite impossible, you can still execute it (from a query execute the string and return SETOF RECORD.
Then you have to specify the return record format. The reason in this case is that the planner needs to know the return format before it can make certain decisions (materialization comes to mind).
So in this case you would EXECUTE the query, return the rows and return SETOF RECORD.
For example, we could do something like this with a wrapper function but the same logic could be folded into your function:
CREATE OR REPLACE FUNCTION crosstab_wrapper
(tablename varchar, rowc varchar, colc varchar,
cellc varchar, celldatatype varchar)
returns setof record language plpgsql as $$
DECLARE outrow record;
BEGIN
FOR outrow IN EXECUTE xtab($1, $2, $3, $4, $5)
LOOP
RETURN NEXT outrow
END LOOP;
END;
$$;
Then you supply the record structure on calling the function just like you do with crosstab.
Then when you all the query you would have to supply a record structure (as (col1 type, col2 type, etc) like you do with connectby.