Linking to OCCI libs generates warnings about std::string - occi

Question

I have created a Static Library project (sll) which is using the std::string. Then I linked it to oraocci12.lib (for release) and oraocci12d.lib (for debug). And just upon linking the static library to the OCCI ones the project generates many warnings about std::string. The warnings are all about already defined symbols, something like:
warning LNK4006: "public: void __cdecl std::basic_string,class std::allocator >::_Copy(unsigned
__int64,unsigned __int64)" (?_Copy#?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##QEAAX_K0#Z)
already defined in oraocci12.lib(oraocci12.dll); second definition
ignored
warning LNK4006: "public: char * __cdecl std::_Wrap_alloc >::allocate(unsigned __int64)"
(?allocate#?$_Wrap_alloc#V?$allocator#D#std###std##QEAAPEAD_K#Z)
already defined in oraocci12.lib(oraocci12.dll); second definition
ignored
warning LNK4006: "public: class std::basic_string,class std::allocator > & __cdecl
std::basic_string,class
std::allocator >::assign(class std::basic_string,class std::allocator > const &,unsigned
__int64,unsigned __int64)" (?assign#?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##QEAAAEAV12#AEBV12#_K1#Z)
already defined in oraocci12.lib(oraocci12.dll); second definition
ignored
warning LNK4006: "public: class std::basic_string,class std::allocator > & __cdecl
std::basic_string,class
std::allocator >::assign(char const *,unsigned __int64)"
(?assign#?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##QEAAAEAV12#PEBD_K#Z)
already defined in oraocci12.lib(oraocci12.dll); second definition
ignored
warning LNK4006: "public: class std::basic_string,class std::allocator > & __cdecl
std::basic_string,class
std::allocator >::erase(unsigned __int64,unsigned __int64)"
(?erase#?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##QEAAAEAV12#_K0#Z)
already defined in oraocci12.lib(oraocci12.dll); second definition
ignored
warning LNK4006: "`string'"
(??_C#_0BA#JFNIOLAK#string?5too?5long?$AA#) already defined in
oraocci12.lib(oraocci12.dll); second definition ignored
warning LNK4006: "`string'"
(??_C#_0BI#CFPLBAOH#invalid?5string?5position?$AA#) already defined in
oraocci12.lib(oraocci12.dll); second definition ignored
I have tried changing the:
Platform Toolset in Project Properties => General.
Character Set in Project Properties => General.
Runtime Library in Project Properties => C/C++ => Code Generation.
Verbose in Project Properties => Librarian => General.
Ignore All default Libraries in Project Properties => Librarian => General.
Also tried linking to different oracle libs:
msvc\vc14\oraocci12.lib (release)
msvc\vc14\oraocci12d.lib (debug)
msvc\oraocci12.lib (release)
msvc\oraocci12d.lib (debug)
I have also tried many combinations of the above, but the problem persists.
IMP: It happens if the project type is sll. If it is changed to dll, then the warnings go away.
Environment details:
Visual Studio Professional 2017 (15.6.7)
Project Type is Static Library (sll, x64)
Windows 10
Oracle instantclient-sdk-windows.x64-12.2.0.1.0
Thanks all!