Pass array from node-postgres to plpgsql function - arrays

Question

The plpgsql function:
CREATE OR REPLACE FUNCTION testarray (int[]) returns int as $$
DECLARE
len int;
BEGIN
len := array_upper($1);
return len;
END
$$ language plpgsql;
The node-postgres query + test array:
var ta = [1,2,3,4,5];
client.query('SELECT testarray($1)', [ta], function(err, result) {
console.log('err: ' + err);
console.log('result: ' + result);
});
Output from node server:
err: error: array value must start with "{" or dimension information
result: undefined
I also tried cast the parameter in the client query like testarray($1::int[]) which returned the same error.
I changed the function argument to (anyarray int) and the output error changed:
err: error: invalid input syntax for integer: "1,2,3,4,5"
result: undefined
As well as a couple other variations.
I seek the variation that produces no error and returns 5.
I read about the Postgres parse-array issue and this stackoverflow question on parameterised arrays in node-postgres:
node-postgres: how to execute "WHERE col IN (<dynamic value list>)" query?
But the answer didn't seem to be there.

Answer 1

The parameter has to be in one of these forms:
'{1,2,3,4,5}' -- array literal
'{1,2,3,4,5}'::int[] -- array literal with explicit cast
ARRAY[1,2,3,4,5] -- array constructor
Also, you can simplify your function:
CREATE OR REPLACE FUNCTION testarray (int[])
RETURNS int AS
$func$
BEGIN
RETURN array_length($1, 1);
END
$func$ LANGUAGE plpgsql IMMUTABLE;
Or a simple SQL function:
CREATE OR REPLACE FUNCTION testarray2 (int[])
RETURNS int AS 'SELECT array_length($1, 1)' LANGUAGE sql IMMUTABLE;
Or just use array_length($1, 1) directly.
array_upper() is the wrong function. Arrays can have arbitrary subscripts. array_length() does what you are looking for. Related question:
Normalize array subscripts for 1-dimensional array so they start with 1
Both array_length() and array_upper() require two parameters. The second is the array dimension - 1 in your case.

Answer 2

thanks to the responses from PinnyM and Erwin. I reviewed the options and reread related answers.
the array formats described by Erwin work in node-postgres literally as follows:
'select testarray(' + "'{1,2,3,4,5}'" + ')'
'select testarray(' + "'{1,2,3,4,5}'" + '::INT[])'
'select testarray(ARRAY[1,2,3,4,5])'
the tl:dr of javascript quoting
to parameterize them in node-postgres:
(based on this answer)
var ta = [1,2,3,4,5];
var tas = '{' + ta.join() + '}';
...skipped over the pg connect code
client.query("select testarray($1)", [tas] ...
client.query("select testarray($1::int[])", [tas] ...
not sure about the ARRAY constructor.

Answer 3

Based on the answer you posted, this might work for you:
var ta = [1,2,3,4,5];
var params = [];
for(var i = 1, i <= ta.length; i++) {
params.push('$'+i);
}
var ta = [1,2,3,4,5];
client.query('SELECT testarray(\'{' + params.join(', ') + '}\')', ta, function(err, result) {
console.log('err: ' + err);
console.log('result: ' + result);
});