CREATE OR REPLACE FUNCTION test(name VARCHAR (255))
RETURNS INTEGER AS
$BODY$
DECLARE
emp_id INTEGER;
BEGIN
SELECT employee.employee_id into emp_id from employee where first_name = name;
DELETE FROM employee WHERE employee_id = emp_id;
return emp_id;
END
$BODY$
LANGUAGE plpgsql;
when i call the function its deleting all the records in my employee table.
First store value in a variable for given input and these execute delete command with this variable and return this variable.
-- PostgreSQL
-- create table and store data
create table employee (emp_id int, name varchar(255));
insert into employee values (1, 'Rahul'), (2, 'Biswas'), (3, 'Shuva');
-- create function
CREATE OR REPLACE FUNCTION test(p_name varchar(255))
RETURNS INTEGER AS
$BODY$
DECLARE v_emp_id INTEGER;
BEGIN
SELECT e.emp_id into v_emp_id from employee e where e.name = p_name;
DELETE FROM employee WHERE emp_id = v_emp_id;
return v_emp_id;
END
$BODY$
LANGUAGE plpgsql;
-- execute function
select * from test('Rahul');
Please check this url https://dbfiddle.uk/?rdbms=postgres_11&fiddle=4c134787dafd8fe58b032d700168318d
Related
I have been working on creating a store procedure that will select data from a table, do some modification to that data, and then I need to insert that modified data into the same table. Take an example my table name is student. My procedure looks like below:
create or replace procedure student_create(p_code varchar)
language plpgsql
as $$
declare
v_student public.student;
begin
select * into v_student from student where code = p_code and is_latest_version is true;
raise notice 'Value: %', v_student;
v_student.id = uuid_generate_v4();
v_student.version_created_at = now();
v_student.version_updated_at = v_student.version_created_at;
raise notice 'Value: %', v_student;
INSERT INTO public.student VALUES(v_student);
end;$$
I am getting errors while calling this procedure:
ERROR: column "id" is of type uuid but expression is of type hotel
LINE 1: INSERT INTO public.hotel VALUES(v_hotel)
I know I can make insert statements like I can get each value from the variable and set it like
INSERT INTO public.student VALUES(v_student.id, v_student.code, v_student.name);
But I don't want to do that because it will become tightly coupled and later if I add another column into the table then I need to add that column into this procedure as well.
Does anyone have idea how can I insert the declared type variable directly into table.
There is no table type, there is only row composite type. Check manual 43.3.4. Row Types.
use row type.
create or replace procedure student_create(p_code text)
language plpgsql
as $$
declare
v_student public.student
begin
for v_student in select * from student where code = p_code and is_latest_version is true
loop
v_student.id = uuid_generate_v4();
v_student.version_created_at = now();
v_student.version_updated_at = v_student.version_created_at;
v_student.is_latest_version = true;
v_student.code = p_code;
INSERT INTO student VALUES(v_student.*);
end loop;
end;$$;
call it: call student_create('hello');
3. use update clause directly.
create or replace procedure student_create_1(p_code text)
language plpgsql as $$
BEGIN
with a as ( select uuid_generate_v4() as id ,
now() as version_created_at,
now() as version_updated_at,
p_code as "code" from student
where code = p_code and is_latest_version is true)
INSERT INTO student(id, version_created_at, version_updated_at, code)
select a.id, a.version_created_at,a.version_updated_at,a."code" from a;
end
$$;
call it: call student_create_1('hello');
fiddle code: here
create or replace function demowhile_()
returns table (id integer,name varchar(50))
language 'plpgsql'
as $$
declare id integer;
declare name varchar(50);
begin
CREATE temporary TABLE demo_(id integer,name varchar(50));
CREATE temporary TABLE temp_ (id integer);
insert into temp_ (select id from demo);
while (select count(*) from temp_) <> 0
loop
id = (select top(1) id from temp_);
name = (select name from demo where id = id);
insert into demo_ values (id,name);
delete from temp_ where id = id;
end loop;
return query select id,name from demo;
end;
$$;
****while executing it is giving error like ****
select * from demowhile();
**ERROR: column reference "id" is ambiguous
LINE 1: insert into temp_ (select id,name from demo)
^
DETAIL: It could refer to either a PL/pgSQL variable or a table column.
QUERY: insert into temp_ (select id,name from demo)
CONTEXT: PL/pgSQL function demowhile() line 9 at SQL statement
SQL state: 42702**
demowhile_() returns table (id integer,name varchar(50) is basically the same thing as demowhile_(out id integer, out name varchar(50)) returns setof record
The id output column can be referenced directly from within the function. You've then also created a function variable named id. So when you assign a value to id, are you assigning to the output parameter or the declared variable? PG doesn't know, so you get that error.
And of course the simple solution is to give each a unique name.
CREATE FUNCTION create_child1()
RETURNS TABLE(sys_user_id integer,
sys_service_id integer
)
LANGUAGE 'plpgsql'
COST 100
VOLATILE
ROWS 1000
AS $BODY$
DECLARE
curr_id CURSOR IS
SELECT id FROM users WHERE id in (3089,3090,3091,3092);
v_id bigint;
BEGIN
OPEN curr_id;
LOOP
FETCH curr_id INTO v_id;
EXIT WHEN not found ;
EXECUTE format('
CREATE TABLE IF NOT EXISTS %I (
sys_user_id integer,
sys_service_id integer
id bigint NOT NULL primary key
)
INHERITS (telemetry_master)
WITH (
OIDS=FALSE
)', 'telemetry_' || v_id);
end loop;
close curr_id;
fetch next from curr_id into v_id;
END
$BODY$ LANGUAGE plpgsql;
You do not need an explicit cursor in your function. You can use a simple FOR ... IN ... LOOP.
It is unclear what you want to return from the function. For example, it can return a readable text about each created table.
CREATE OR REPLACE FUNCTION create_child1()
RETURNS SETOF text LANGUAGE plpgsql
AS $BODY$
DECLARE
v_id int;
BEGIN
FOR v_id IN 3089..3092 LOOP
EXECUTE format('
CREATE TABLE IF NOT EXISTS telemetry_%s (
sys_user_id integer,
sys_service_id integer,
id bigint NOT NULL primary key
)
INHERITS (telemetry_master)', v_id);
RETURN NEXT format('telemetry_%s created.', v_id);
END LOOP;
END $BODY$;
Use:
SELECT create_child1();
create_child1
-------------------------
telemetry_3089 created.
telemetry_3090 created.
telemetry_3091 created.
telemetry_3092 created.
(4 rows)
If the ids are not consecutive you can use unnest(), e.g.:
FOR v_id IN SELECT id FROM unnest(array[3000,3001,3020,3021]) AS id LOOP
I'm trying to insert data from one table to another in postgres using for...loop. The approach is given below.
DO LANGUAGE PLPGSQL $$
DECLARE
data record;
BEGIN
FOR data IN SELECT * FROM forall_data
LOOP
INSERT INTO for_loop values data;<br>
END LOOP;
END;
$$
I've used record for the row iteration but couldn't find out how to insert that 'data' into 'for_loop' table. When I run this code it gives me the following error:
ERROR: syntax error at or near "data"
LINE 9: INSERT INTO for_loop values data;
^
Here are my two tables.
create table forall_data(
nid numeric(15,0)not null,
name varchar(15) not null,
city varchar(10) not null,
contact numeric(11,0) not null
);
create table for_loop(
nid numeric(15,0)not null,
name varchar(15) not null,
city varchar(10) not null,
contact numeric(11,0) not null
);
What should I try here to insert that 'data' record into 'for_loop' table? Thanks in advance.
'data' is untyped record, so I have to mention the column name to retrieve the value of this record.
DO LANGUAGE PLPGSQL $$
DECLARE
data record;
BEGIN
FOR data IN SELECT * FROM forall_data
LOOP
INSERT INTO for_loop values (data.nid,data.name,data.city,data.contact);
END LOOP;
END;
$$
But using %rowtype or table type is more flexible and no need to mention the column names to retrieve column value from the variable
DO LANGUAGE PLPGSQL $$
DECLARE
data forall_data; --- or data forall_data%rowtype
BEGIN
FOR data IN SELECT * FROM forall_data
LOOP
INSERT INTO for_loop select (data).*;
END LOOP;
END;
$$
cheers :)
use this code:
DO LANGUAGE PLPGSQL $$
DECLARE
rec record;
BEGIN
FOR rec IN SELECT * FROM budzet.forall_data
LOOP
INSERT INTO budzet.for_loop(nid, name , city , contact)
VALUES (rec.nid, rec.name , rec.city , rec.contact);
END LOOP;
END;
$$
You can try Loop with some exit condition.
DO LANGUAGE PLPGSQL $$
DECLARE
rec CURSOR FOR SELECT * FROM forall_data;
V_nid numeric;
V_name varchar(15);
V_city varchar(10);
V_contact numeric;
BEGIN
OPEN rec;
LOOP
FETCH rec INTO V_nid ,V_name ,V_city,V_contact;
EXIT WHEN(rec IS NULL);
INSERT INTO for_loop(nid, name , city , contact)
VALUES (V_nid , V_name , V_city , V_contact);
END LOOP;
CLOSE rec;
END;
$$
Hope it work for you.
EDIT: Alternately you can try this without using loop insert statement from one table and select statement from another table.
INSERT INTO for_loop(nid, name , city , contact)
select nid, name , city , contact FROM forall_data;
I have a view which contains 3 tables. I want to update the each tables contained in the view.
Tables:
Table 1: test1
create table test1
(
id int,
name text,
city text
);
insert into test1 values(1,'Abc','xyz');
Table 2: test2
create table test2
(
id int,
name text,
city text
);
insert into test2 values(1,'bc','xz');
Table 3: test3
create table test3
(
id int,
name text,
city text
);
insert into test3 values(1,'Ac','yz');
View:
create view myview as select * from test1 union all select * from test2 union all select * from test3;
Note: I have a situation where I need to update the all tables city at once. So I have written a function
which does the update for a single table.
create or replace function updatefun(tablename text)
returns void as
$body$
Declare
query varchar;
Begin
query := 'Update '||tablename||'
set city = ''XXX''';
raise info '%',query;
execute query;
end;
$body$
Language plpgsql;
I have another table which contains the ViewId and ViewName.
create table viewdetails
(
ViewId int,
ViewName text
);
insert into viewdetails values(101,'myview');
Now I want to write another function to get all tables from the view and want to call the
function updatefun from this function to update all tables.
My try:
create or replace function fun1(vId int)
returns void as
$body$
declare
query varchar;
rec1 record;
rec2 record;
begin
DROP TABLE IF EXISTS temp_table1;
create temp table temp_table1(viewNames text);
query := 'insert into temp_table1 select ViewName from ViewDetails where ViewId = '|| vId ||'';
execute query;
for rec1 in select ViewNames from temp_table1 loop
for rec2 in SELECT Table_Name FROM INFORMATION_SCHEMA.VIEW_TABLE_USAGE WHERE View_Name = 'rec1' loop
select updatefun('rec2');
end loop;
end loop;
end;
$body$
language plpgsql;
Calling Function:
select fun1(101);
Checking view:
select * from myview;
Not getting why it is not getting updated??
This is incorrect:
select updatefun('rec2');
You want
perform updatefun(rec2);
without any quotes around rec2 otherwise it's interpreted as a literal, not the name of a variable.
Additionally rec2 should be of type TEXT, not RECORD.