09_list_tables.c

// SPDX-License-Identifier: MIT

#include <stdio.h>
#include <stdlib.h>
#include <libpq-fe.h>

void do_exit(PGconn *conn)
{
	PQfinish(conn);
	exit(1);
}

int main(void)
{
	PGconn *conn = PQconnectdb("host=localhost port=5432 user=postgres password=postgres dbname=api_data");

	if (PQstatus(conn) == CONNECTION_BAD) {
		fprintf(stderr, "Connection to database failed: %s\n", PQerrorMessage(conn));
		do_exit(conn);
	}

	PGresult *res = PQexec(conn, "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'");

	if (PQresultStatus(res) != PGRES_TUPLES_OK) {
		printf("No data retrieved\n");
		PQclear(res);
		do_exit(conn);
	}

	int rows = PQntuples(res);

	for (int i = 0; i < rows; i++)
		printf("%s\n", PQgetvalue(res, i, 0));

	PQclear(res);
	PQfinish(conn);

	return 0;
}