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.
Related
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 have a fields table to store column information for other tables:
CREATE TABLE public.fields (
schema_name varchar(100),
table_name varchar(100),
column_text varchar(100),
column_name varchar(100),
column_type varchar(100) default 'varchar(100)',
column_visible boolean
);
And I'd like to create a function to fetch data for a specific table.
Just tried sth like this:
create or replace function public.get_table(schema_name text,
table_name text,
active boolean default true)
returns setof record as $$
declare
entity_name text default schema_name || '.' || table_name;
r record;
begin
for r in EXECUTE 'select * from ' || entity_name loop
return next r;
end loop;
return;
end
$$
language plpgsql;
With this function I have to specify columns when I call it!
select * from public.get_table('public', 'users') as dept(id int, uname text);
I want to pass schema_name and table_name as parameters to function and get record list, according to column_visible field in public.fields table.
Solution for the simple case
As explained in the referenced answers below, you can use registered (row) types, and thus implicitly declare the return type of a polymorphic function:
CREATE OR REPLACE FUNCTION public.get_table(_tbl_type anyelement)
RETURNS SETOF anyelement AS
$func$
BEGIN
RETURN QUERY EXECUTE format('TABLE %s', pg_typeof(_tbl_type));
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM public.get_table(NULL::public.users); -- note the syntax!
Returns the complete table (with all user columns).
Wait! How?
Detailed explanation in this related answer, chapter
"Various complete table types":
Refactor a PL/pgSQL function to return the output of various SELECT queries
TABLE foo is just short for SELECT * FROM foo:
Is there a shortcut for SELECT * FROM?
2 steps for completely dynamic return type
But what you are trying to do is strictly impossible in a single SQL command.
I want to pass schema_name and table_name as parameters to function and get record list, according to column_visible field in
public.fields table.
There is no direct way to return an arbitrary selection of columns (return type not known at call time) from a function - or any SQL command. SQL demands to know number, names and types of resulting columns at call time. More in the 2nd chapter of this related answer:
How do I generate a pivoted CROSS JOIN where the resulting table definition is unknown?
There are various workarounds. You could wrap the result in one of the standard document types (json, jsonb, hstore, xml).
Or you generate the query with one function call and execute the result with the next:
CREATE OR REPLACE FUNCTION public.generate_get_table(_schema_name text, _table_name text)
RETURNS text AS
$func$
SELECT format('SELECT %s FROM %I.%I'
, string_agg(quote_ident(column_name), ', ')
, schema_name
, table_name)
FROM fields
WHERE column_visible
AND schema_name = _schema_name
AND table_name = _table_name
GROUP BY schema_name, table_name
ORDER BY schema_name, table_name;
$func$ LANGUAGE sql;
Call:
SELECT public.generate_get_table('public', 'users');
This create a query of the form:
SELECT usr_id, usr FROM public.users;
Execute it in the 2nd step. (You might want to add column numbers and order columns.)
Or append \gexec in psql to execute the return value immediately. See:
How to force evaluation of subquery before joining / pushing down to foreign server
Be sure to defend against SQL injection:
INSERT with dynamic table name in trigger function
Define table and column names as arguments in a plpgsql function?
Asides
varchar(100) does not make much sense for identifiers, which are limited to 63 characters in standard Postgres:
Maximum characters in labels (table names, columns etc)
If you understand how the object identifier type regclass works, you might replace schema and table name with a singe regclass column.
I think you just need another query to get the list of columns you want.
Maybe something like (this is untested):
create or replace function public.get_table(_schema_name text, _table_name text, active boolean default true) returns setof record as $$
declare
entity_name text default schema_name || '.' || table_name;
r record;
columns varchar;
begin
-- Get the list of columns
SELECT string_agg(column_name, ', ')
INTO columns
FROM public.fields
WHERE fields.schema_name = _schema_name
AND fields.table_name = _table_name
AND fields.column_visible = TRUE;
-- Return rows from the specified table
RETURN QUERY EXECUTE 'select ' || columns || ' from ' || entity_name;
RETURN;
end
$$
language plpgsql;
Keep in mind that column/table references may need to be surrounded by double quotes if they have certain characters in them.
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
I want to loop through a query, but also retain the actual record for the next loop, so I can compare two adjacent rows.
CREATE OR REPLACE FUNCTION public.test ()
RETURNS void AS
$body$
DECLARE
previous RECORD;
actual RECORD;
query TEXT;
isdistinct BOOLEAN;
tablename VARCHAR;
columnname VARCHAR;
firstrow BOOLEAN DEFAULT TRUE;
BEGIN
tablename = 'naplo.esemeny';
columnname = 'esemeny_id';
query = 'SELECT * FROM ' || tablename || ' LIMIT 2';
FOR actual IN EXECUTE query LOOP
--do stuff
--save previous record
IF NOT firstrow THEN
EXECUTE 'SELECT ($1).' || columnname || ' IS DISTINCT FROM ($2).' || columnname
INTO isdistinct USING previous, actual;
RAISE NOTICE 'previous: %', previous.esemeny_id;
RAISE NOTICE 'actual: %', actual.esemeny_id;
RAISE NOTICE 'isdistinct: %', isdistinct;
ELSE
firstrow = false;
END IF;
previous = actual;
END LOOP;
RETURN;
END;
$body$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER
COST 100;
The table:
CREATE TABLE naplo.esemeny (
esemeny_id SERIAL,
felhasznalo_id VARCHAR DEFAULT "current_user"() NOT NULL,
kotesszam VARCHAR(10),
idegen_azonosito INTEGER,
esemenytipus_id VARCHAR(10),
letrehozva TIMESTAMP WITHOUT TIME ZONE DEFAULT now() NOT NULL,
szoveg VARCHAR,
munkalap_id VARCHAR(13),
ajanlat_id INTEGER,
CONSTRAINT esemeny_pkey PRIMARY KEY(esemeny_id),
CONSTRAINT esemeny_fk_esemenytipus FOREIGN KEY (esemenytipus_id)
REFERENCES naplo.esemenytipus(esemenytipus_id)
ON DELETE RESTRICT
ON UPDATE RESTRICT
NOT DEFERRABLE
)
WITH (oids = true);
The code above doesn't work, the following error message is thrown:
ERROR: could not identify column "esemeny_id" in record data type
LINE 1: SELECT ($1).esemeny_id IS DISTINCT FROM ($2).esemeny_id
^
QUERY: SELECT ($1).esemeny_id IS DISTINCT FROM ($2).esemeny_id
CONTEXT: PL/pgSQL function "test" line 18 at EXECUTE statement
LOG: duration: 0.000 ms statement: SET DateStyle TO 'ISO'
What am I missing?
Disclaimer: I know the code doesn't make too much sense, I only created so I can demonstrate the problem.
This does not directly answer your question, and may be of no use at all, since you did not really describe your end goal.
If the end goal is to be able to compare the value of a column in the current row with the value of the same column in the previous row, then you might be much better off using a windowing query:
SELECT actual, previous
FROM (
SELECT mycolumn AS actual,
lag(mycolumn) OVER () AS previous
FROM mytable
ORDER BY somecriteria
) as q
WHERE previous IS NOT NULL
AND actual IS DISTINCT FROM previous
This example prints the rows where the current row is different from the previous row.
Note that I added an ORDER BY clause - it does not make sense to talk about "the previous row" without specifying ordering, otherwise you would get random results.
This is plain SQL, not PlPgSQL, but if you can wrap it in a function if you want to dynamically generate the query.
I am pretty sure, there is a better solution for your actual problem. But to answer the question asked, here is a solution with polymorphic types:
The main problem is that you need well known composite types to work with. the structure of anonymous records is undefined until assigned.
CREATE OR REPLACE FUNCTION public.test (actual anyelement, _col text
, OUT previous anyelement) AS
$func$
DECLARE
isdistinct bool;
BEGIN
FOR actual IN
EXECUTE format('SELECT * FROM %s LIMIT 3', pg_typeof(actual))
LOOP
EXECUTE format('SELECT ($1).%1$I IS DISTINCT FROM ($2).%1$I', _col)
INTO isdistinct
USING previous, actual;
RAISE NOTICE 'previous: %; actual: %; isdistinct: %'
, previous, actual, isdistinct;
previous := actual;
END LOOP;
previous := NULL; -- reset dummy output (optional)
END
$func$ LANGUAGE plpgsql;
Call:
SELECT public.test(NULL::naplo.esemeny, 'esemeny_id')
I am abusing an OUT parameter, since it's not possible to declare additional variables with a polymorphic composite type (at least I have failed repeatedly).
If your column name is stable you can replace the second EXECUTE with a simple expression.
I am running out of time, explanation in these related answers:
Declare variable of composite type in PostgreSQL using %TYPE
Refactor a PL/pgSQL function to return the output of various SELECT queries
Asides:
Don't quote the language name, it's an identifier, not a string.
Do you really need WITH (oids = true) in your table? This is still allowed, but largely deprecated in modern Postgres.
I have plpgsql function:
CREATE OR REPLACE FUNCTION test() RETURNS VOID AS
$$
DECLARE
my_row my_table%ROWTYPE;
BEGIN
SELECT * INTO my_row FROM my_table WHERE id='1';
my_row.date := now();
END;
$$ LANGUAGE plpgsql;
I would like to know if it's possible to directly UPDATE my_row record.
The only way I've found to do it now is:
UPDATE my_table SET date=now() WHERE id='1';
Note this is only an example function, the real one is far more complex than this.
I'm using PostgreSQL 9.2.
UPDATE:
Sorry for the confusion, what I wanted to say is:
SELECT * INTO my_row FROM my_table INTO my_row WHERE id='1';
make_lots_of_complicated_modifications_to(my_row, other_complex_parameters);
UPDATE my_row;
I.e. Use my_row to persist information in the underlying table. I have lots of parameters to update.
I would like to know if it's possible to directly update "my_row"
record.
It is.
You can update columns of a row or record type in plpgsql - just like you have it. It should be working, obviously?
This would update the underlying table, of course, not the variable!
UPDATE my_table SET date=now() WHERE id='1';
You are confusing two things here ...
Answer to clarification in comment
I don't think there is syntax in PostgreSQL that can UPDATE a whole row. You can UPDATE a column list, though. Consider this demo:
Note how I use thedate instead of date as column name, date is a reserved word in every SQL standard and a type name in PostgreSQL.
CREATE TEMP TABLE my_table (id serial, thedate date);
INSERT INTO my_table(thedate) VALUES (now());
CREATE OR REPLACE FUNCTION test_up()
RETURNS void LANGUAGE plpgsql AS
$func$
DECLARE
_r my_table;
BEGIN
SELECT * INTO _r FROM my_table WHERE id = 1;
_r.thedate := now()::date + 5 ;
UPDATE my_table t
-- explicit list of columns to be to updated
SET (id, thedate) = (_r.id, _r.thedate)
WHERE t.id = 1;
END
$func$;
SELECT test_up();
SELECT * FROM my_table;
However, you can INSERT a whole row easily. Just don't supply a column list for the table (which you normally should, but in this case it is perfectly ok, not to).
As an UPDATE is internally a DELETE followed by an INSERT anyway, and a function automatically encapsulates everything in a transaction, I don't see, why you couldn't use this instead:
CREATE OR REPLACE FUNCTION x.test_ delins()
RETURNS void LANGUAGE plpgsql AS
$func$
DECLARE
_r my_table;
BEGIN
SELECT * INTO _r
FROM my_table WHERE id = 1;
_r.thedate := now()::date + 10;
DELETE FROM my_table t WHERE t.id = 1;
INSERT INTO my_table SELECT _r.*;
END
$func$;
I managed to get this working in PLPGSQL in a couple of lines of code.
Given a table called table in a schema called example, and a record of the same type declared as _record, you can update all the columns in the table to match the record using the following hack:
declare _record example.table;
...
-- get the columns in the correct order, as a string
select string_agg(format('%I', column_name), ',' order by ordinal_position)
into _columns
from information_schema.columns
where table_schema='example' and table_name='table';
execute 'update example.table set (' || _columns || ') = row($1.*) where pkey=$2'
using _record, _record.pkey;
In the above example, of course, _record.pkey is the table's primary key.
Postgresql has not set row in update.
If you wont update full row you should assign value for each column separately
yes, its possible to update / append the row-type variable,
CREATE OR REPLACE FUNCTION test() RETURNS VOID AS $$
DECLARE
my_row my_table%ROWTYPE;
BEGIN
SELECT * INTO my_row FROM my_table WHERE id='1';
my_row.date := now();
raise notice 'date : %; ',my_row.date;
END;
$$ LANGUAGE plpgsql;
here the raise notice will display the today's date only.
but this will not update the column date in my_table.