The picture below presents the structure of the library, together with its clients and servers. The boxes filled with cyan represent components that are part of the library distribution.

Structure Chart

The SOCI library is extensible in the following ways:

The core part of the library and the backend interface definition are placed in the core directory of the library distribution. The soci-backend.h file is an internal abstract interface to the actual backends, which are needed to perform operations on the given database server. Normally, the C++ client program needs to interface with the soci.h header and the header(s) relevant to the given backend(s) (for example, soci-oracle.h), although with dynamic backend loading this can be avoided. It is possible for the same program to use many backends at the same time.

Everything in SOCI is declared in the namespace soci. All code examples presented in this documentation assume that your code begins with something like:

#include "soci.h"
// other includes if necessary

using namespace soci;

// ...

Note: In simple programs, #include for the relevant backend is needed only in the file where the session object is created with explicit name of the backend factory. The example program on the previous page shows the appropriate #include directive for the Oracle backend. It is also possible to name backends at run-time as part of the connection string, in which case no backend-specific #include directive is necessary.