这是代码,直接来自示例。64 位安装,x64 构建。
#include "postgres.h"
#include "executor/spi.h"
#include "commands/trigger.h"
#include "fmgr.h"
#include "access/heapam.h"
#include "utils/syscache.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
PGDLLEXPORT Datum plsample_call_handler(PG_FUNCTION_ARGS); // <-- the answer!!
PG_FUNCTION_INFO_V1(plsample_call_handler);
Datum
plsample_call_handler(PG_FUNCTION_ARGS)
{
Datum retval;
retval = 42;
return retval;
}
它编译并链接OK。这是SQL:
CREATE FUNCTION plsample_call_handler() RETURNS language_handler
AS 'TryPostgresPl.dll'
LANGUAGE C;
CREATE LANGUAGE plsample
HANDLER plsample_call_handler;
这是错误消息。
ERROR: could not find function "plsample_call_handler" in file "C:/Program Files/PostgreSQL/9.5/lib/TryPostgresPl.dll"
SQL state: 42883
如此之近,却又如此之远。真的不知道在哪里看。
根据尼克·巴恩斯(Nick Barnes)编辑以显示答案。请注意,查看depends.exe 之前显示了2 个导出,现在是3 个。