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.
In PostgreSQL, the UPDATE command is used to change the present records in a table. To update the selected rows, we have to use the WHERE clause; otherwise, all rows would be updated.
Syntax. UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition]; You can combine N number of conditions using AND or OR operators.
PostgreSQL implements multiversioning by keeping the old version of the table row in the table – an UPDATE adds a new row version (“tuple”) of the row and marks the old version as invalid. In many respects, an UPDATE in PostgreSQL is not much different from a DELETE followed by an INSERT .
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 ...
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
$func$;
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