How to pass a param for a binding in PostgreSQL - COPY (... ) TO STDOUT (FORMAT binary)? - sql

Question

I have some simple test table in postgres like below:
--DROP TABLE test_point
CREATE TABLE test_point
(
serie_id INT NOT NULL,
version_ts INT NOT NULL,
PRIMARY KEY (serie_id, version_ts)
);
I try to load a data from it by using COPY TO STDOUT and binary buffers. This is sql definition I use in a test case:
COPY (
SELECT version_ts
FROM test_point
WHERE
serie_id = $1::int
) TO STDOUT (FORMAT binary);
It works ok, if I don't provide any param to bind to in SQL. If I use simple select it recognizes params also as well.
I was trying to provide explicit info about param type during stmt preparation also, but results were similar (it doesn't recognize param).
This is a message I receive during the test case:
0x000001740a288ab0 "ERROR: bind message supplies 1 parameters, but prepared statement \"test1\" requires 0\n"
How to properly provide a param for COPY() statement?
I don't want to cut/concatenate strings for timestamp params and similar types.
Below is a test case showing the issue.
TEST(TSStorage, CopyParamTest)
{
auto sql = R"(
COPY (
SELECT version_ts
FROM test_point
WHERE
serie_id = $1::int
) TO STDOUT (FORMAT binary);
)";
auto connPtr = PQconnectdb("postgresql://postgres:pswd#localhost/some_db");
auto result = PQprepare(connPtr, "test1", sql, 0, nullptr);
// Lambda to test result status
auto testRes = [&](ExecStatusType status)
{
if (PQresultStatus(result) != status)
{
PQclear(result);
auto errorMsg = PQerrorMessage(connPtr);
PQfinish(connPtr);
throw std::runtime_error(errorMsg);
}
};
testRes(PGRES_COMMAND_OK);
PQclear(result);
int seriesIdParam = htonl(5);
const char *paramValues[] = {(const char *)&seriesIdParam};
const int paramLengths[] = {sizeof(seriesIdParam)};
const int paramFormats[] = {1}; // 1 means binary
// Execute prepared statement
result = PQexecPrepared(connPtr,
"test1",
1, //nParams,
paramValues,
paramLengths,
paramFormats,
1); // Output format - binary
// Ensure it's in COPY_OUT state
//testRes(PGRES_COPY_OUT);
if (PQresultStatus(result) != PGRES_COPY_OUT)
{
auto errorMsg = PQerrorMessage(connPtr);
int set_breakpoint_here = 0; // !!! !!! !!!
}
PQclear(result);
PQfinish(connPtr);
}