How do I insert this custom data type with libpq?

Question

I'm having some difficulty with inserting some data using libpq. I have two custom data types:

create type size as (width real, height real);
create type rotated_rect as (angle real, center point, bounding_box box, size size)

and I would like to insert a record into a table which has a rotated_rect field, so for the field using libpq I'm putting together the string value:

paramv[3] = "(10.5,10.1,10.2,20,20,20,40,(5,5))";

However, it's giving me the error: invalid input syntax for type point: "10.1"

I've also tried:

paramv[3] = "(10.5,(10.1,10.2),20,20,20,40,(5,5))"; -> invalid input syntax for "(10.1"
paramv[3] = "(10.5,(10.1,10.2),(20,20,20,40),(5,5))"; -> as above

and the sql command I'm using is:

res = PQexecParams(conn, "insert into test (r,b,s,rr) values ($1::real,$2::box,$3::size,$4::rotated_rect)", 4, NULL, paramv, NULL, NULL,0);

How do I fix this?

Answer 1

What got me were that escaped double quotes and parenthesis need to be used around the values representing a field of the custom compound data type which requires more than one value to create, so:

paramv[0] = "(10.5,\"(10.1,10.2)\",\"(20,20,20,40)\",\"(5,5)\")";

As this string is used as a parameter, the single quotes that would usually wrap the outer parenthesis are not needed.

In a non-parameterised query, it would be implemented like so with the single quotes:

res = PQexec(conn, "insert into test (rr) values ('(10.5,\"(10.1,10.2)\",\"(20,20,20,40)\",\"(5,5)\")')");

Answer 2

This works (tested in Postgres 9.3):

SELECT '(10.5,"(10.1,10.2)","(20,20,20,40)","(5,5)")'::rotated_rect

Returns:

'(10.5,"(10.1,10.2)","(20,40),(20,20)","(5,5)")'

Note the different syntax for box. Try this form.