I would like to create a function that returns a column of a table as an integer array.
In other words, how can I transfrom the result of SELECT id FROM mytable to integer[] ?
You can do:
SELECT ARRAY(SELECT id FROM mytable)
Or:
SELECT array_agg(id) FROM mytable
Related
I have integer Array like {10,13,20}
I have to pass this array in IN condition like
SELECT count(*) FROM table WHERE id IN (10,20,30)
I tried:
SELECT count(*) FROM table WHERE id IN(array_to_string(_array,','))
but it's throwing the error casting operator does not exist: bigint = text
Thanks in advance
you can use below query:
Demo
SELECT count(*) FROM test WHERE id = any(array[10,20,30]::int[]);
Use string_to_array instead of array_to_string. Cast the resulting array to bigint[] as the type of id is bigint. Here it is, easy to be parameterized:
SELECT count(*) FROM users u
WHERE id = any(string_to_array('10,20,30',',')::bigint[]);
After your clarification that _array is an argument or variable of type bigint[] then simply:
SELECT count(*) FROM users u WHERE id = any(_array);
I would like to store a table variable as to be accessed by another query within a function. Here is what I have so far.
CREATE OR REPLACE FUNCTION suggest(p_id INTEGER)
RETURNS TABLE (
r_id INT,
i_id INT
) AS $$
DECLARE
p_record INT[];
BEGIN
SELECT ingredient_id INTO p_record FROM shop_ingredients
WHERE item_id IN
(SELECT item_id FROM basket
WHERE user_id = p_id);
...
I am not sure whether the type of p-record should be an array of INTEGER or a RECORD. Within the function I would like to access such list of values, for example:
HAVING SUM(ingredient_id = ANY(p_record)) >= (COUNT(*)*0.6)
How can I achieve this? I have searched endlessly to understand how to manage this but to no avail.
The problem with creating a table, like so:
CREATE TEMP TABLE IF NOT EXISTS p_record
AS SELECT ingredient_id
FROM shop_ingredients
WHERE item_id IN
(SELECT item_id FROM basket
WHERE user_id = p_id);
is that if p_id parameter changes, the p_record variables does not.
Maybe the following SQL function can help:
create or replace function suggest(p_id int)
returns table (i_id int)
language sql
as
$$
select ingredient_id
from shop_ingredient
where item_id in
(select item_id from basket
where user_id = p_id);
$$;
Note that the SELECT statement column list must exactly match the TABLE clause after RETURNS keyword and this function is only SQL so no need of BEGIN/END block or intermediate record variable.
I am trying to write sub-queries so that I search all tables for a column named id and since there are multiple tables with id column, I want to add the condition, so that id = 3119093.
My attempt was:
Select *
from information_schema.tables
where id = '3119093' and id IN (
Select table_name
from information_schema.columns
where column_name = 'id' );
This didn't work so I tried:
Select *
from information_schema.tables
where table_name IN (
Select table_name
from information_schema.columns
where column_name = 'id' and 'id' IN (
Select * from table_name where 'id' = 3119093));
This isn't the right way either. Any help would be appreciated. Thanks!
A harder attempt is:
CREATE OR REPLACE FUNCTION search_columns(
needle text,
haystack_tables name[] default '{}',
haystack_schema name[] default '{public}'
)
RETURNS table(schemaname text, tablename text, columnname text, rowctid text)
AS $$
begin
FOR schemaname,tablename,columnname IN
SELECT c.table_schema,c.table_name,c.column_name
FROM information_schema.columns c
JOIN information_schema.tables t ON
(t.table_name=c.table_name AND t.table_schema=c.table_schema)
WHERE (c.table_name=ANY(haystack_tables) OR haystack_tables='{}')
AND c.table_schema=ANY(haystack_schema)
AND t.table_type='BASE TABLE'
--AND c.column_name = "id"
LOOP
EXECUTE format('SELECT ctid FROM %I.%I WHERE cast(%I as text) like %L',
schemaname,
tablename,
columnname,
needle
) INTO rowctid;
IF rowctid is not null THEN
RETURN NEXT;
END IF;
END LOOP;
END;
$$ language plpgsql;
select * from search_columns('%3119093%'::varchar,'{}'::name[]) ;
The only problem is this code displays the table name and column name. I have to then manually enter
Select * from table_name where id = 3119093
where I got the table name from the code above.
I want to automatically implement returning rows from a table but I don't know how to get the table name automatically.
I took the time to make it work for you.
For starters, some information on what is going on inside the code.
Explanation
function takes two input arguments: column name and column value
it requires a created type that it will be returning a set of
first loop identifies tables that have a column name specified as the input argument
then it forms a query which aggregates all rows that match the input condition inside every table taken from step 3 with comparison based on ILIKE - as per your example
function goes into the second loop only if there is at least one row in currently visited table that matches specified condition (then the array is not null)
second loop unnests the array of rows that match the condition and for every element it puts it in the function output with RETURN NEXT rec clause
Notes
Searching with LIKE is inefficient - I suggest adding another input argument "column type" and restrict it in the lookup by adding a join to pg_catalog.pg_type table.
The second loop is there so that if more than 1 row is found for a particular table, then every row gets returned.
If you are looking for something else, like you need key-value pairs, not just the values, then you need to extend the function. You could for example build json format from rows.
Now, to the code.
Test case
CREATE TABLE tbl1 (col1 int, id int); -- does contain values
CREATE TABLE tbl2 (col1 int, col2 int); -- doesn't contain column "id"
CREATE TABLE tbl3 (id int, col5 int); -- doesn't contain values
INSERT INTO tbl1 (col1, id)
VALUES (1, 5), (1, 33), (1, 25);
Table stores data:
postgres=# select * From tbl1;
col1 | id
------+----
1 | 5
1 | 33
1 | 25
(3 rows)
Creating type
CREATE TYPE sometype AS ( schemaname text, tablename text, colname text, entirerow text );
Function code
CREATE OR REPLACE FUNCTION search_tables_for_column (
v_column_name text
, v_column_value text
)
RETURNS SETOF sometype
LANGUAGE plpgsql
STABLE
AS
$$
DECLARE
rec sometype%rowtype;
v_row_array text[];
rec2 record;
arr_el text;
BEGIN
FOR rec IN
SELECT
nam.nspname AS schemaname
, cls.relname AS tablename
, att.attname AS colname
, null::text AS entirerow
FROM
pg_attribute att
JOIN pg_class cls ON att.attrelid = cls.oid
JOIN pg_namespace nam ON cls.relnamespace = nam.oid
WHERE
cls.relkind = 'r'
AND att.attname = v_column_name
LOOP
EXECUTE format('SELECT ARRAY_AGG(row(tablename.*)::text) FROM %I.%I AS tablename WHERE %I::text ILIKE %s',
rec.schemaname, rec.tablename, rec.colname, quote_literal(concat('%',v_column_value,'%'))) INTO v_row_array;
IF v_row_array is not null THEN
FOR rec2 IN
SELECT unnest(v_row_array) AS one_row
LOOP
rec.entirerow := rec2.one_row;
RETURN NEXT rec;
END LOOP;
END IF;
END LOOP;
END
$$;
Exemplary call & output
postgres=# select * from search_tables_for_column('id','5');
schemaname | tablename | colname | entirerow
------------+-----------+---------+-----------
public | tbl1 | id | (1,5)
public | tbl1 | id | (1,25)
(2 rows)
I have a PostgreSQL function similar to this:
CREATE OR REPLACE FUNCTION dbo.MyTestFunction(
_ID INT
)
RETURNS dbo.MyTable AS
$$
SELECT *,
(SELECT Name FROM dbo.MySecondTable WHERE RecordID = PersonID)
FROM dbo.MyTable
WHERE PersonID = _ID
$$ LANGUAGE SQL STABLE;
I would really like to NOT have to replace the RETURNS dbo.MyTable AS with something like:
RETURNS TABLE(
col1 INT,
col2 TEXT,
col3 BOOLEAN,
col4 TEXT
) AS
and list out all the columns of MyTable and Name of MySecondTable. Is this something that can be done? Thanks.
--EDIT--
To clarify I have to return ALL columns in MyTable and 1 column from MySecondTable. If MyTable has >15 columns, I don't want to have to list out all the columns in a RETURNS TABLE (col1.. coln).
You just list the columns that you want returned in the SELECT portion of your SQL statement:
SELECT t1.column1, t1.column2,
(SELECT Name FROM dbo.MySecondTable WHERE RecordID = PersonID)
FROM dbo.MyTable t1
WHERE PersonID = _ID
Now you'll just get column1, column3, and name returned
Furthermore, you'll probably find better performance using a LEFT OUTER JOIN in your FROM portion of the SQL statement as opposed to the correlated subquery you have now:
SELECT t1.column1, t1.column2, t2.Name
FROM dbo.MyTable t1
LEFT OUTER JOIN dbo.MySecondTable t2 ON
t2.RecordID = t1.PersonID
WHERE PersonID = _ID
Took a bit of a guess on where RecordID and PersonID were coming from, but that's the general idea.
In postgres, can you set the value of an array in an INSERT to the result of a subquery? Like:
INSERT INTO mytable
VALUES( SELECT list_of_integers FROM someothertable WHERE somekey = somevalue);
Where that mytable just has as its one column a type of integer[] and that other column list_of_integers is also type integer[] ?
You want the unnest function. I think you'd use it like:
INSERT INTO mytable
SELECT set_of_integers
FROM unnest(
SELECT list_of_integers
FROM someothertable
WHERE somekey = somevalue
) t(set_of_integers)
But i don't have PostgreSQL to hand to try it out myself.
Yes:
INSERT INTO
mytable
(column1, column2, an_array_of_integers_column)
VALUES
(2, 'bbb', (SELECT list_of_integers FROM someothertable WHERE somekey = somevalue));