CREATE OR REPLACE FUNCTION change_trigger() RETURNS trigger AS $$
BEGIN
INSERT INTO static_table_name (content) VALUES (to_jsonb(NEW));
END;
$$ LANGUAGE 'plpgsql' SECURITY DEFINER;
↑ is working, but I'd like to have opportunity to send target table name for inserting.
So,
by the code above, I was able to use dymanic_table_name,
CREATE OR REPLACE FUNCTION change_trigger() RETURNS trigger AS $$
DECLARE
dymanic_table_name TEXT;
BEGIN
dymanic_table_name := TG_ARGV[0];
EXECUTE 'INSERT INTO ' || dymanic_table_name || ' (content) VALUES (' || to_json(NEW) || ');';
END;
$$ LANGUAGE 'plpgsql' SECURITY DEFINER;
but it fails, when try to insert result of 'to_json' function...
ERROR:
ERROR: "{"またはその近辺で構文エラー
LINE 1: ..._table (content) VALUES ({"id":43,"...
^
※ Sorry for Japanese syntax ( *´艸｀)
You'll have to use dynamic SQL like this:
EXECUTE
format(
'INSERT INTO %I (content) VALUES (to_json($1))',
dymanic_table_name
)
USING NEW;
Related
I am having some issues figuring out how to run multiple dynamic queries in a single function.
CREATE OR REPLACE FUNCTION cnms_fy22q2.test_function(
fyq text)
RETURNS void
LANGUAGE 'plpgsql'
COST 100
VOLATILE
AS $BODY$
BEGIN
-- logic
TRUNCATE TABLE 'schema_' || fyq || '.my_table'
DROP TABLE 'schema_' || fyq || '.my_table';
END;
$BODY$;
I am generally getting syntax errors, like ERROR: syntax error at or near .... What am I doing wrong here?
You can't simply concatenate strings to make a dynamic sql statement. Take a look at EXECUTE and EXECUTE IMMEDIATE.
In your case, you could use it like this:
CREATE OR REPLACE FUNCTION cnms_fy22q2.test_function(
fyq text)
RETURNS void
LANGUAGE 'plpgsql'
COST 100
VOLATILE
AS $BODY$
BEGIN
-- logic
EXECUTE 'TRUNCATE TABLE schema_' || fyq || '.my_table';
EXECUTE 'DROP TABLE schema_' || fyq || '.my_table';
END
$BODY$;
Use the format function which will return a string and execute in your function.
create function permanently_delete_table(fyq text) RETURNS void
LANGUAGE plpgsql AS $$
declare
begin
EXECUTE format('TRUNCATE TABLE schema_%s.my_table',fyq);
EXECUTE format('DROP TABLE schema_%s.my_table',fyq);
end
$$;
Demo in sqldaddy.io
Just to add a third option that I came up with which combines the queries inside a single EXECUTE format(); statement, here's what I came up with:
CREATE OR REPLACE FUNCTION cnms_fy22q2.drop_summary_tables_function(
fyq text)
RETURNS void
LANGUAGE 'plpgsql'
COST 100
VOLATILE
AS $BODY$
BEGIN
-- logic
EXECUTE format(
'TRUNCATE TABLE schema_%s.my_table;
DROP TABLE schema_%s.my_table', fyq, fyq);
END;
$BODY$;
Below is a simplified postgres stored procedure I am trying to run:
create or replace procedure my_schema.tst(suffix varchar)
as $$
begin
execute(' select *
into my_schema.MyTable_'||suffix||'
From my_schema.MyTable
');
end;
$$
language plpgsql;
When I attempt to run using something like:
call my_schema.tst('test');
I get this error Invalid operation: EXECUTE of SELECT ... INTO is not supported;
Is it possible to execute a dynamic query that creates a new table? I have seen examples that look like:
Execute('... some query ...') into Table;
but for my use case I need the resulting tablename to be passed as a variable.
In PostgreSQL you can use INSERT INTO tname SELECT...
create or replace procedure my_schema.tst(suffix varchar)
as $$
begin
execute ' INSERT INTO my_schema.MyTable_'||suffix||' SELECT *
FROM my_schema.MyTable
';
end;
$$
language plpgsql;
or Use CREATE TABLE tname AS SELECT..., :
create or replace procedure my_schema.tst(suffix varchar)
as $$
begin
execute ' CREATE TABLE my_schema.MyTable_'||suffix||' as SELECT *
FROM my_schema.MyTable
';
end;
$$
language plpgsql;
I checked all related questions on SO but none helped in my case.
I have 2 loops(outside for the tables and inside for the columns). Tables are represented by 'r', and columns by 'm'. While being inside the 'm' loop which is supposed to send column values to the to-be-created trigger function. When I try to use 'NEW.m' (with trying many different formatting attempts) compiler always gives error.
Can you kindly advice on it please? Br
FOR r IN SELECT table_name FROM information_schema.tables LOOP
FOR m IN SELECT column_name FROM information_schema.columns WHERE (table_name = r.table_name ) LOOP
function_name := 'dictionary_functions_foreach_trigger';
EXECUTE format('CREATE OR REPLACE FUNCTION %s()
RETURNS trigger AS
$BODY$
DECLARE
BEGIN
IF NEW.m IS NOT NULL AND NEW.m IN (SELECT key FROM tableX.tableX_key)
THEN RETURN NEW;
END IF;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION %s()
OWNER TO mydb;',function_name, function_name);
EXECUTE 'CREATE TRIGGER ' || function_name || ' BEFORE INSERT OR UPDATE ON ' || belonging_to_schema || '.' || r.table_name || ' FOR EACH ROW EXECUTE PROCEDURE ' || function_name || '();';
----Trigger Functions after edit-
EXECUTE format(
'CREATE OR REPLACE FUNCTION %s()
RETURNS trigger AS
$BODY$
DECLARE
insideIs text := %s ;
BEGIN
FOR %s IN 0..(TG_NARGS-1) LOOP
IF %I= TG_ARGV[%s]
THEN insideIs := %s ;
END IF;
END LOOP;
IF NEW.%I IS NOT NULL AND (insideIs =%s) AND NEW.%I IN (SELECT key FROM tableX.tableX_key)
THEN RETURN NEW;
ELSE RETURN OLD;
END IF;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION %s()
OWNER TO mydb;' , function_name, 'notInside', 'i' , m.column_name, 'i' , 'ok', m.column_name, 'ok', m.column_name ,function_name);
You need to use another placeholder for the column name, they way you have written it, the column name "m" is hardcoded in the function.
You also don't really need the outer loop, as the table_name is also available in information_schema.columns.
Your trigger would also fail with a runtime error if the condition is not true as you don't have a return in that case. If you want to abort the statement, use return null;
You should also use format() for the create trigger statement.
FOR m IN SELECT table_schema, table_name, column_name
FROM information_schema.columns
WHERE table_name in (...)
LOOP
function_name := 'dictionary_functions_foreach_trigger';
EXECUTE format('CREATE OR REPLACE FUNCTION %I()
RETURNS trigger AS
$BODY$
DECLARE
BEGIN
IF NEW.%I IS NOT NULL AND NEW.%I IN (SELECT key FROM tableX.tableX_key) THEN
RETURN NEW;
END IF;
RETURN null; --<< you need some kind of return here!
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION %s()
OWNER TO mydb;', function_name, m.column_name, m.column_name, function_name, function_name);
EXECUTE format('CREATE TRIGGER %I BEFORE INSERT OR UPDATE ON %I.%I FOR EACH ROW EXECUTE PROCEDURE %I()',
function_name, m.table_schema, m.table_name, function_name);
END LOOP;
Online example
I wrote a PL/pgsql to batch create index on tables
CREATE OR REPLACE FUNCTION create_index() RETURNS void AS
$BODY$
DECLARE
r INTEGER;
BEGIN
FOR r IN 1..1000
LOOP
EXECUTE format(
' CREATE INDEX idx_abc_id_' || r::text ||
' ON abc_id_' || r::text ||
' USING btree
(key);');
END LOOP;
RETURN;
END
$BODY$
LANGUAGE plpgsql;
it has one problem, if partition abc_500 doesn't exist, then the how create index function will fail and do nothing.
How to make loop keep going through even if create_index made an error on one of the table in between?
I think a better approach would be to not hardcode the number for the loop, but iterate over the existing tables:
CREATE OR REPLACE FUNCTION create_index() RETURNS void AS
$BODY$
DECLARE
r record;
BEGIN
FOR r IN select tablename, regexp_replace(tablename, '[^0-9]+','') as idx_nr
from pg_tables
where tablename ~ 'abc_id_[0-9]+'
LOOP
EXECUTE format('CREATE INDEX %I ON %I USING btree (key)',
'idx_abc_id_'||r.idx_nr,
r.tablename);
END LOOP;
RETURN;
END
$BODY$
LANGUAGE plpgsql;
When you use the format() function is better to use the proper place holders for identifiers.
If you also want to ignore any error when creating the index on an existing table, you need to catch the exception and ignore it:
CREATE OR REPLACE FUNCTION create_index() RETURNS void AS
$BODY$
DECLARE
r record;
msg text;
BEGIN
FOR r IN select tablename, regexp_replace(tablename, '[^0-9]+','') as idx_nr
from pg_tables
where tablename ~ 'abc_id_[0-9]+'
LOOP
BEGIN
EXECUTE format('CREATE INDEX %I ON %I USING btree (key)',
'idx_abc_id_'||r.idx_nr,
r.tablename);
EXCEPTION
WHEN OTHERS THEN
GET STACKED DIAGNOSTICS msg = MESSAGE_TEXT;
RAISE NOTICE 'Could not create index for: %, %', r.idx_nr, msg;
END;
END LOOP;
RETURN;
END
$BODY$
LANGUAGE plpgsql;
I have a string to execute with the string aggregate function within the postgresql function. Here is the following script for that.
Example:
create or replace function f(colvalue int,colnvalue varchar)
returns void as
$$
declare
sql varchar;
var varchar;
begin
sql := 'Select var:= string_agg(................) /* Error occurred here near var:= */
from tablename where cola ='|| colvalue || ' AND coln ='|| colnvalue;
raise notice '%'sql;
execute sql into var;
raise notice var;
end;
$$
language plpgsql;
Error:
ERROR: syntax error at or near ":="
Note: I want the result of string_agg into var.
Dynamic SQL can contains SQL statement only - but ":=" is a PL/pgSQL statement. Next, it is clean from your example, so it is useless there. Second issue is a SQL injection vulnerability (still this code should not work). Newer use a patter ' || varcharvar || ' for SQL used in dynamic SQL.
CREATE OR REPLACE FUNCTION f(colvalue int,colnvalue varchar)
RETURNS void AS $$
DECLARE
sql varchar;
var varchar;
BEGIN
sql := 'SELECT string_agg(..) FROM tablename WHERE cola=$1 AND coln=$2';
RAISE NOTICE '%', sql;
EXECUTE sql INTO var USING colvalue, colnvalue;
RAISE NOTICE '%', var;
END;
$$ LANGUAGE plpgsql;