The Informix driver for Informix (IDS) 7.x, SE 7.x, Universal Server (IUS) 9.x and IDS
2000 is implemented in "ifx.ec" and "php3_ifx.h" in the informix extension directory. IDS 7.x
support is fairly complete, with full support for BYTE and TEXT columns. IUS 9.x support is partly
finished: the new data types are there, but SLOB and CLOB support is still under construction.
Configuration notes: You need a version of ESQL/C to compile the PHP Informix driver.
ESQL/C versions from 7.2x on should be OK. ESQL/C is now part of the Informix Client SDK.
Make sure that the "INFORMIXDIR" variable has been set, and that $INFORMIXDIR/bin is in
your PATH before you run the "configure" script.
The configure script will autodetect the libraries and include directories, if you run
"configure --with_informix=yes". You can override this detection by specifying "IFX_LIBDIR",
"IFX_LIBS" and "IFX_INCDIR" in the environment. The configure script will also try to detect your
Informix server version. It will set the "HAVE_IFX_IUS" conditional compilation variable if your
Informix version >= 9.00.
Some notes on the use of BLOBs (TEXT and BYTE columns): BLOBs are normally addressed by
BLOB identifiers. Select queries return a "blob id" for every BYTE and TEXT column. You can get at
the contents with "string_var = ifx_get_blob($blob_id);" if you choose to get the BLOBs in memory
(with : "ifx_blobinfile(0);"). If you prefer to receive the content of BLOB columns in a file, use
"ifx_blobinfile(1);", and "ifx_get_blob($blob_id);" will get you the filename. Use normal file I/O
to get at the blob contents.
For insert/update queries you must create these "blob id's" yourself with "ifx_create_blob();". You then plug the blob id's into an
array, and replace the blob columns with a question mark (?) in the query string. For
updates/inserts, you are responsible for setting the blob contents with ifx_update_blob().
The behaviour of BLOB columns can be altered by configuration variables that also can be
set at runtime :
configuration variable : ifx.textasvarchar
configuration variable : ifx.byteasvarchar
runtime functions :
ifx_textasvarchar(0) : use blob id's for select queries with TEXT columns
ifx_byteasvarchar(0) : use blob id's for select queries with BYTE columns
ifx_textasvarchar(1) : return TEXT columns as if they were VARCHAR columns, so that you
don't need to use blob id's for select queries.
ifx_byteasvarchar(1) : return BYTE columns as if they were VARCHAR columns, so that you
don't need to use blob id's for select queries.
configuration variable : ifx.blobinfile
runtime function :
ifx_blobinfile_mode(0) : return BYTE columns in memory, the blob id lets you get at the
contents.
ifx_blobinfile_mode(1) : return BYTE columns in a file, the blob id lets you get at the
file name.
If you set ifx_text/byteasvarchar to 1, you can use TEXT and BYTE columns in select
queries just like normal (but rather long) VARCHAR fields. Since all strings are "counted" in PHP,
this remains "binary safe". It is up to you to handle this correctly. The returned data can contain
anything, you are responsible for the contents.
If you set ifx_blobinfile to 1, use the file name returned by ifx_get_blob(..) to get at
the blob contents. Note that in this case YOU ARE RESPONSIBLE FOR DELETING THE TEMPORARY FILES
CREATED BY INFORMIX when fetching the row. Every new row fetched will create new temporary files
for every BYTE column.
The location of the temporary files can be influenced by the environment variable
"blobdir", default is "." (the current directory). Something like : putenv(blobdir=tmpblob"); will
ease the cleaning up of temp files accidentally left behind (their names all start with "blb").
