I have a few threads in my application. Each has its own PGconn* connection that is individually opened with the same connection string. When a thread makes a query, it almost never returns PGRES_TUPLES_OK.
我的应用程序中有几个线程。每个都有自己的PGconn *连接，使用相同的连接字符串单独打开。当一个线程进行查询时，它几乎永远不会返回PGRES_TUPLES_OK。
I can provide some code examples if necessary, but does anything stand out here? I have tried using global mutexes as well, to no avail. I am using postgresql 9.3
如有必要，我可以提供一些代码示例，但这里有什么突出的东西吗？我也试过使用全局互斥锁，但无济于事。我正在使用postgresql 9.3
PQerrorMessage(db) returns: connection pointer is NULL
PQerrorMessage（db）返回：连接指针为NULL
From the postgresql documentation: If a null pointer is returned, it should be treated like a PGRES_FATAL_ERROR result. Use PQerrorMessage to get more information about the error.
从postgresql文档：如果返回空指针，则应将其视为PGRES_FATAL_ERROR结果。使用PQerrorMessage获取有关错误的更多信息。
1 个解决方案
#1
0
Ok, I figured it out.
好的，我明白了。
I was using a function to open each connection, and was passing a pointer to a PGconn struct to it.
我正在使用一个函数来打开每个连接，并将指向PGconn结构的指针传递给它。
I needed to pass a double pointer.
我需要传递一个双指针。
#1
0
Ok, I figured it out.
好的，我明白了。
I was using a function to open each connection, and was passing a pointer to a PGconn struct to it.
我正在使用一个函数来打开每个连接，并将指向PGconn结构的指针传递给它。
I needed to pass a double pointer.
我需要传递一个双指针。