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));
Related
I am inserting data into a table and want to return the inserted data. The inserted data contains foreign keys. I would like to get the whole data with the joins of the foreign keys.
I have tried putting a SELECT in RETURNING without luck. Is this even possible or do I just have to do another query after inserting the data?
Insert statement:
INSERT INTO someTable (col1, col2, col3, foreign_id)
VALUES ('value1', 'value2', 'value3', 1);
So in this case, could I have a RETURNING that basically would give me:
SELECT someTable.*, foreignTable.*
FROM someTable
JOIN foreignTable ON someTable.foreign_id = foreignTable.id;
demo:db<>fiddle
You can use a CTE for this:
WITH inserting AS (
INSERT INTO...
RETURNING <new data>
)
SELECT i.*, ft.*
FROM inserting i JOIN foreign_table ft ...
In this case the INSERT statement will be executed. The SELECT statement will be executed after that. This can reference the inserted data.
You can use a CTE for that:
with new_row as (
INSERT INTO some_table (col1, col2, col3, foreign_id)
VALUES ('value1', 'value2', 'value3', 1)
returning *
)
SELECT new_row.*, ft.*
FROM new_row
JOIN foreign_table ft ON new_row.foreign_id = ft.id;
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.
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
I want to select from an enumaration that is not in database.
E.g. SELECT id FROM my_table returns values like 1, 2, 3
I want to display 1 -> 'chocolate', 2 -> 'coconut', 3 -> 'pizza' etc. SELECT CASE works but is too complicated and hard to overview for many values. I think of something like
SELECT id, array['chocolate','coconut','pizza'][id] FROM my_table
But I couldn't succeed with arrays. Is there an easy solution? So this is a simple query, not a plpgsql script or something like that.
with food (fid, name) as (
values
(1, 'chocolate'),
(2, 'coconut'),
(3, 'pizza')
)
select t.id, f.name
from my_table t
join food f on f.fid = t.id;
or without a CTE (but using the same idea):
select t.id, f.name
from my_table t
join (
values
(1, 'chocolate'),
(2, 'coconut'),
(3, 'pizza')
) f (fid, name) on f.fid = t.id;
This is the correct syntax:
SELECT id, (array['chocolate','coconut','pizza'])[id] FROM my_table
But you should create a referenced table with those values.
What about creating another table that enumerate all cases, and do join ?
CREATE TABLE table_case
(
case_id bigserial NOT NULL,
case_name character varying,
CONSTRAINT table_case_pkey PRIMARY KEY (case_id)
)
WITH (
OIDS=FALSE
);
and when you select from your table:
SELECT id, case_name FROM my_table
inner join table_case on case_id=my_table_id;
Is it possible to select from an insert statement? For example:
SELECT id FROM (INSERT INTO table (col1, col2) VALUES (val1, val2));
Where id is an autoincrementing primary key.
It's not possible in such way, because INSERT doesn't return virtual table for SELECT. However you could get id's actual value using currval(regclass) sequence function as:
SELECT currval('yourTableName_id_seq'::regclass);
currval
---------
1
(1 row)
EDIT:
Use RETURNING clause (available since PostgreSQL 8.2):
INSERT INTO yourTableName (col1, col2) VALUES ('aaa', 'bbb') RETURNING id;
id
----
2
(1 row)
"SELECT id FROM mytable WHERE id IS NULL;
"id" has to be an auto_increment column to make it work.
It will return the last_insert_id just as last_insert_id() is expected to do.
example:
mysql> INSERT INTO orders (customer_cust_id, orderdatetime, message, taxrate, shippingprice)
-> SELECT '1', NOW(), null, taxrate, shippingprice FROM customer
-> WHERE cust_id='1';"
http://dev.mysql.com/doc/refman/5.0/en/insert-select.html