我在 Postgres 9.5 数据库上有下表:
\d t_rstats
Table "public.t_rstats"
Column | Type | Collation | Nullable | Default
-----------+---------+-----------+----------+---------
eid | bigint | | not null |
timestamp | integer | | not null |
mids | hstore | | |
Run Code Online (Sandbox Code Playgroud)
我正在尝试使用 libpq 库/API 的PQsendQuery从 C++ 执行以下 SQL 命令。
SELECT eid, timestamp, mids->'1144' AS m1144 FROM t_rstats
WHERE timestamp BETWEEN 1608638528 AND 1608638618
AND eid IN (3568,3600,4088,4120,4608,4640,5128,5160,5648,5680,6584)
ORDER BY eid, timestamp
Run Code Online (Sandbox Code Playgroud)
作为参考,准备上述 SQL 的 C++ 代码的一部分
std::vector<unsigned> metric_ids;
string selected_fields("SELECT …Run Code Online (Sandbox Code Playgroud)