Welcome to libpqxx, a C++ API to the PostgreSQL database management system.

This file documents building and installation of libpqxx on Windows systems.
Please see the regular README for general instructions on building, installing,
and using the library.  If you are using Cygwin, MSYS, or another Unix-like
environment please try the Unix configuration & build procedure instead of the
one described here.  Some help for the MSYS/MinGW combination is given below,
but in general, things are much more complicated for Windows than they are for
other environments.

The only Windows compilers currently documented here are:

	Visual C++ (7.0 or above)
	MinGW

If you are using a different compiler, such as Borland C++ Builder, you should
still be able to get it to work.  If you do, or if you fail, please report your
results so any problems can be resolved and support for the compiler can be
included in the standard libpqxx distribution.

Throughout this document, we'll be using the command line.


Build Environment

Before you start, make sure your development environment is reasonably up to
date.  If you use MSYS, be sure your "grep" program is up to date and that you
have the "mktemp" program installed (these can be downloaded from
http://gnuwin32.sf.net/).  If you use Visual C++, make sure you have at least
version 7.0 or you'll run into serious compilation trouble.

Next, make sure you have a working installation of libpq, the C-level client
library included with PostgreSQL.  Note that for some reason, enabling the
"Include and Library Files" in the graphical PostgreSQL installer may not be
enough to ensure this.

The best way to ensure that you have libpq available, on a Windows system, is to
compile a recent version of PostgreSQL from source.  Its source tree should
then contain libpq in binary form, as well as its headers.  Look for these in
src/interfaces/libpq: Visual C++ will generate separate Debug and Release
versions in subdirectories called Debug and Release, respectively, in that
location.  Note these locations; they will become important in the next section.

The source package for PostgreSQL can be obtained from http://postgresql.org/

To build PostgreSQL with Visual C++, "cd" into the source tree and run:

	VCVARS32.BAT
	nmake /f win32.mak

You'll also want to build a Debug-flavour libpq, so then run:

	nmake /f win32.mak DEBUG=1

The libpq binaries will be produced in src/interfaces/libpq/Release and
src/interface/libpq/Debug, respectively, and the Debug versions will have an
extra "D" in their names.

(Instructions for building PostgreSQL with MinGW are given in the MSYS section
below).

The rest of this text will assume that you have the libpq library in its binary 
form(s), as well as its header files.  Now, to work on building libpqxx!


Preparing to Compile libpqxx

Before you can build libpqxx you need to provide certain common settings.

  i) Copy win32/common-sample to win32/common, and edit the latter to reflect
    the paths to your PostgreSQL includes and library files.
    On Windows these may differ from one person's system to another, but if you
    compiled PostgreSQL for yourself to obtain libpq, simply set the PGSQLSRC in
    win32/common to point to the "src" subdirectory in your PostgreSQL source
    tree.
    You may also have to edit the LIBPATH1 and LIBPATH2 variables to point to
    where your actual libpq library is.  There are two of these because
    Visual C++ will normally produce two flavours ("release" and "debug") of the
    library, and the build procedure may need to find either, depending on which
    flavour of libpqxx build you'll be doing.

 ii) If you cannot run the configure script: Create the configuration headers,
    include/pqxx/config-*-*.h.  The easiest start for this is to copy from
    available samples.  In config/sample-headers, find the directories most
    accurately describing your compiler and libpq version, respectively.  Take
    the config-*-*.h headers from those directories and copy them into the
    include/pqxx/ directory.
    On a Unix-like system these headers would be generated automatically by the
    configure script; in the Windows case they may need some editing.  How these
    files work is described in more detail below.

iii) If you are building from a development source tree rather than from a
    release distribution, you may not have the makefiles for your compiler.
    These makefiles should be in the win32 directory and have names ending in
    ".mak".  If you have python, you can generate them using the template2mak.py
    script in the tools directory:

    ./tools/template2mak.py win32/mingw.mak.template win32/mingw.mak
    ./tools/template2mak.py win32/vc-libpqxx.mak.template win32/vc-libpqxx.mak
    ./tools/template2mak.py win32/vc-test.mak.template win32/vc-test.mak


The rest of the procedure depends on your compiler.

If you're using Visual C++:
1) Run VCVARS32.BAT to prepare the environment.  Then CD into the main directory
   of the libpqxx source tree.  Among other things it will contain the files 
   "configure" and "Makefile.am," and subdirectories "src," "include," "win32"
   etc.
2) Run "nmake /f win32/vc-libpqxx.mak ALL" will compile all dynamic, static,
   debug and release libraries.  Once completed, you will find them in the
   win32/lib directory.

If you're using MinGW (but without a Unix-like environment, see above):
1) Run "make -f win32/MinGW.mak"
2) Consider installing a Unix-like environment like MSYS to automate all this!

After that, it is recommended that you compile and run the self-test programs
included in the package.  Unix, Cygwin, or MSYS users simply type "make check"
to build and run the entire regression test.  For Visual C++ users, the
following steps should accomplish the same:

 3) "nmake /f win32\vc-test.mak ALL" will compile and link all the test files.
    It is currently set to use the DLL version of libpqxx.
 4) Make sure a PostgreSQL database is running and accessible; set up the
    environment as described in README so that the test programs can access the
    database without needing to pass a connection string.
 5) Run each of the test programs in order.  Some of them will generate lots of
    output, some won't produce any.  Error messages that are expected in the
    course of a normal test run are prefixed with "(Expected)" to show that they
    are not harmful.  All tests should complete successfully.

Here's how to set up a Visual C++ project file for your own program using
libpqxx (based on description by Alexandre Hanft, 2006-03-06):

 6) Create a new project in the Visual C++ development environment.
 7) Add your first C++ file and provide some initial code, e.g. by copying the
    test/test001.cxx source file from the libpqxx source tree.
 8) Edit Project Properties, C++: Additional Include Directories.  Add the
    location of the "include" directory found in your libpqxx source tree, e.g.
    C:\src\libpqxx\include if you keep libpqxx in C:\src\libpqxx.
 9) Edit Project Properties, Linker: Additional Library Directories.  Add the
    directories where your libpq and libpqxx libraries are, for example:
    C:\src\postgresql-8.1.3\interfaces\libpq\Release;C:\src\libpqxx\win32\lib
    That is for your Release build.  Do the same for your Debug build, but
    replace that "Release" in there with "Debug" there.
10) Edit Project Properties, Linker, Input: Additional Dependencies.  Add:
    libpqxx.lib.
11) Your program should build successfully now.  It may not be ready to run yet,
    because some dynamically loaded libraries are needed when starting your
    program.  Copy comerr32.dll and krb5_32.dll from the "bin" directory in your
    PostgreSQL directory tree, and the libpqxx DLLs from win32/lib in your
    libpqxx tree, directly into your project's directory so the system can find
    them when your development environment launches your program.
12) Your program should now be able to run.  However, you may need to tell it
    how to connect to a database.  If you set the environment variables
    PGDATABASE, PGHOST, PGPORT, and PGUSER as described in the libpqxx README
    file, your program should be able to connect without passing further
    parameters.  Sensible defaults are provided for all of these variables; if
    you have a database running on your local machine, with the same name as
    your username, and you are allowed to log into that without password (this
    is the default on some systems), then no settings should be needed.
13) Once your program gets to the point where users should be able to configure
    it properly, change them to pass a connection string where it connects to
    any databases, and include your user's configuration settings.  A typical
    connection string setting all parameters named above might look like:
	"dbname=testbase user=testuser host=my.dbserver.somewhere.com"
14) For any other problems, please check the project homepage as listed in the
    main libpqxx README file.


Getting Started with MinGW and MSYS
(based on contribution by Michael J. Pedersen, 2004-08-17)

MSYS is a Unix-like environment for Windows.  Once you have this installed,
building libpqxx should be a lot more like it is under Unix except that the
locations of libraries and such aren't sufficiently standardized.

Packages to download if you don't have them already:
1) MinGW (http://www.mingw.org/), plus any updates.
2) MSYS (http://www.mingw.org/), again with any updates.
3) w32api (http://www.mingw.org/).
4) PostgreSQL (http://www.postgresql.org/).
5) zlib (http://www.zlib.org/).

It is generally recommended to get the latest versions of these packages.

Compiling and installing PostgreSQL before you get to libpqxx:
1) Install MinGW (install to c:\mingw)
2) Install MSYS--but not into MinGW directory tree!
3) Run MSYS (Start->Programs->MinGW->MSYS->msys)
4) Extract, compile, and install zlib
    # From main source directory of zlib:
    ./configure --prefix=c:/mingw/local && make && make install
5) Extract, compile, and install postgres
    # From main source directory of PostgreSQL:
    ./configure --prefix=c:/mingw/local --with-includes=c:/mingw/local/include --with-libs=c:/mingw/local/lib
    make && make install
6) Extract, compile, and install libpqxx
    export LDFLAGS=-lws2_32
    ./configure --prefix=c:/mingw/local --enable-static
    make && make install

If you don't have and don't want to install MSYS, you won't be able to perform
the "./configure" step.  You can build libpqxx without it, but it takes a bit
more work and doesn't build the self-test.  Use the special makefile MinGW.mak
in the win32 directory instead of the regular Makefile, and follow the procedure
described below to use the prefabricated configuration headers enclosed in the
source archive.

Building libpqxx without MSYS:

	# (first set up configuration headers, see below)
	export LDFLAGS=-lws2_32
	make -f win32/MinGW.mak
	# (install library, headers and pqxx-config manually on your system)

Having installed libpqxx, when compiling your own programs, use the following
steps (examples only here):

g++ -c -o myfile.o myfile.cpp `pqxx-config --cflags`
g++ -o myexec myfile.o `pqxx-config --libs` -lws2_32

Note that the linker step (g++ -o myexec) will give a spurious warning
about not knowing how to use the -R flag, but the executable will still
be generated, and work just fine.

The last argument to that linker step MUST be -lws2_32.  Without it, the link
will provide errors about undefined references to select(). If it's not the last
argument, you will get the same results.  Make sure it's there, and make sure
it's last. Trust me, you'll be happier.


Setting up the configuration headers

Several headers, normally generated by the configure script, define certain
aspects of your compilation environment so that the library can work around
compiler shortcomings, functions missing in older libpq versions, etc.  (Samples
for various compiler and libpq versions can be found in the subdirectory
config/sample-headers, so if you find you need to provide these headers
yourself, look there first.)

Each of the aspects mentioned below is represented by a configuration item--a
preprocessor macro that is either #define'd to some value or not defined at all.
Most of the items are of a Boolean nature, i.e.  some feature or workaround is
enabled if the corresponding macro is defined or disabled if the macro is left
undefined.  Note that defining these macros to anything at all, even 0, means
that the corresponding option is enabled.  They are normally defined to 1, but
that value seems to have been chosen more for convention than anything else.

A few of the items require a textual value however, e.g. PGSTD needs to be
defined to the name of the standard namespace.  You'll typically want to have
this defined to "std" (leave out the quotes though!), but you may want to change
that if you use a standard library other than the default one shipped with your
compiler.

At the time of writing, there are 3 of these configuration headers that you
need to concern yourself about, all of which should be created in the
include/pqxx subdirectory:

	config-internal-compiler.h
	config-internal-libpq.h
	config-public-compiler.h


The names contain two variables:

1. Internal or public.  Configuration items that affect the compilation of
your client program are located in the config-public-*.h files (currently only
one file); ones that affect only the compilation of the library itself are kept
in the config-internal-*.h ones and are not included at all when compiling
client programs.  Public configuration items (except PGSTD) are prefixed with
PQXX_ to avoid clashes with macros defined by other code.

2. Autotools-related, compiler-related, or libpq-related.  The autotools items
are of no real interest, but the compiler and libpq ones are different.  The
compiler-related ones describe features and shortcomings of the compiler
environment, such as the availability of the <unistd.h> header or the ability
to compile certain complex C++ language constructs.  The libpq items describe
what features are available in the version of libpq you're compiling against.
At the time of writing, the latter all take the HAVE_... form; defining such a
macro indicates that the corresponding feature is available.

A complete list of configuration items and their categorizations can be found in
the configitems file.  The normal configure script reads the list of items from
include/pqxx/config.h.in and writes them to include/pqxx/config.h, then splits
them up into the five smaller files as directed by the configitems database.

Again, sample versions of these headers for various compilers and libpq versions
can be found in the config/sample-headers/ directory.  Try copying the three
headers for the compiler and libpq version most resembling your own environment
to include/pqxx/ and, if you have any problems compiling with those, editing
them by hand to enable or disable features that appear to be giving you trouble.


Shared and Static Libraries, or .DLL vs. .LIB

There are two ways to build the libpqxx library: as a shared library (known
in the Unix world as a Shared Object or "so," but in the Windows world as a
Dynamically Loaded Library or DLL) or as a static library (whose name would
end in ".a" on Unix systems but in ".LIB" on Windows systems).  Linking your
own applications to these types of libraries is quite similar, except with a
DLL the system will also have to be able to find the library when your program
is loaded--not just when you are compiling it.

Unlike the situation in the Unix world, however, your choice on this point must
be known as you compile your application code.  With libpqxx you do this by
defining the preprocessor macro PQXX_SHARED when compiling your code for use
with a libpqxx DLL.  Leave this definition out if you intend to link to the
static version of the library.

(Internally, when compiling libpqxx, this variable will also be set according to
which kind of library is being built.  It has a slightly different meaning in
that case, but this should really only matter to you if you are helping debug
the library)

Similarly, you may choose to link to either the static or the shared version of
libpq.  The default is to use the dynamic library, which makes more sense there
because libpq's API and ABI are much simpler and more stable.  To build a
libpqxx for use with a static libpq, however, define the preprocessor symbol
PQXX_PQ_STATIC both when compiling libpqxx and while building your own
application.


Troubleshooting: config headers

The biggest typical problem for Windows/VC++ users is the need to edit the
configuration headers manually, resulting usually in compile errors, e.g. for
missing header files.  Thus, if you get a compile error, the first places to
look are the config-*-*.h and config-*-*.h files in include/pqxx.

If, for instance, the error states that the header file <sys/select.h> is
missing, you will find a configuration variable called PQXX_HAVE_SYS_SELECT_H,
which should not be set if your system doesn't have sys/select.h.  Remove the
line defining this variable from the configuration header where it is defined
(see the configitems file for a list of locations) and the error should
disappear on the next compilation attempt.

If you have to edit your configuration headers, please send your results to the
author or to the libpqxx-general mailing list so that headers corresponding to
your environment can be included in later libpqxx releases.  Be sure to give a
usable personal name so you can be properly credited in the changelog!

CAUTION: DO NOT try to unset yes/no configuration items by defining their macros
to zero.  A value of zero counts as "yes."  If a macro is defined at all, that
means "yes" (or "true," or "enabled" etc.) regardless of what actual value you
set.  To disable an item, make sure it is not defined at all.


Troubleshooting: linking

When you link your application to libpqxx on Windows, you may also need to link
to wsock32.lib.  On Visual C++, add these in the compiler user interface under:

Project Properties::Linker::Input::Additional Dependencies

We recommend that you specify libpqxx_static.lib and wsock32.lib there, in that
order.