Aubit4GL: connecting to mysql and informix concurrently

Since database connections seems to be compile time, and you have to set A4GL_SQLTYPE in order to compile against database X - I wonder how you can open concurrent connections.. I cannot find any documentation on how to do this - but according to http://aubit4gl.sourceforge.net/aubit4gldoc/manual/html/features_summary.html it maybe that you have to use ODBC connections to each instead of native??

It seems that "open session" and "use session" can be used to dynamically switch at runtime. But compile time seems to be the kicker.. especially if you use "define x like table.column" in 4gl, unless it allows "define x like db.table.column" or searches both databases.

Aubit4GL: mysql connection specification

Since this is not well documented on Aubit4gl site, posting here:

To connect to mysql database:

1. Make sure your mysql server is not bound to localhost - even local connections are via hostname
2. Make sure you can connect to mysql server.. grant at least select privs using "grant select on db.* to 'test'@'hostname' identified by 'test';" NOTE: localhost privs are not enough - connection thru hostname.
   
3. Do "export MYSQL_SERVER=hostname"
   
4. Set/export the following environment variables:
   

A4GL_SQLUID=test #whatever connection user is
A4GL_SQLPWD=test #whatever connection password is
A4GL_LEXDIALECT=INFORMIX
A4GL_LEXTYPE=C
A4GL_SQLTYPE=mysql

And now take the simple.4gl program:

database test # of whatever your database name is

main
display "Hello World"
end main

Compile with : aubit 4glpc simple.4gl -o simple.4ae

If it compiles - database connection is ok!

Thanks to Mike's comment below - using .aubit4gl.acl to store database:user:pw DOES work.. just be sure to "unset A4GL_SQLUID" and "unset A4GL_SQLPWD".

Aubit4GL and libmysqld

Had a frustrating time trying to build aubit4gl on ubuntu with mysql support.

/usr/bin/ld: /usr/lib/mysql/libmysqld.a(net_serv.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC
/usr/lib/mysql/libmysqld.a: could not read symbols: Bad value

This is from libmysqlclient15-dev package. Turns out its not even an ubuntu issue.. its actual mysql bug:

http://bugs.mysql.com/bug.php?id=39288

I did see somewhere that it was fixed in libmysqlclient16-dev - which is not available in hardy (8.04) which I need.

I stumbled upon this link and was able to build a relocatable libmysqld.. but then I ran it this:

gcc -shared -L/lib -o /opt/aubit4gl/src/plugins-1.10RC_62/libSQL_mysqldb.so db-mysql.o -L/usr/local/lib -L/usr/local/mysql -L/usr/lib/mysql -L/usr/lib -L/opt/aubit4gl/src/lib -lmysqld -laubit4gl-1.10RC_62 -Wl,-Bsymbolic-functions -L/usr/lib/mysql -lmysqld -lwrap -lrt
/usr/bin/ld: cannot find -lwrap

even though libwrap is in /lib .. arrrg ok.. so I did the following:

cd lib/libsql/mysql
gcc -shared -L/lib -o /opt/aubit4gl/src/plugins-1.10RC_62/libSQL_mysqldb.so db-mysql.o -L/usr/local/lib -L/usr/local/mysql -L/usr/lib/mysql -L/usr/lib -L/opt/aubit4gl/src/lib -lmysqld -laubit4gl-1.10RC_62 -Wl,-Bsymbolic-functions -L/usr/lib/mysql -lmysqld
cd ../../..
make

(ie. I just removed -lwrap and -lrt and it went ok) and proceeded to compile the remainder of aubit4gl. Now to test against mysql