This section holds common questions about relation
between PHP and databases. Yes, PHP can access virtually any
database available today.
On Windows machines, you can simply use the
included ODBC support and the correct ODBC driver.
On Unix machines, you can use the Sybase-CT driver
to access Microsoft SQL Servers because they are (at
least mostly) protocol-compatible. Sybase has made a free version of the necessary libraries
for Linux systems. For other Unix operating
systems, you need to contact Sybase for the correct
libraries. Also see the answer to the next
question.
Yes. You already have all the tools you need if you
are running entirely under Windows 9x/Me, or NT/2000,
where you can use ODBC and Microsoft's ODBC drivers for
Microsoft Access databases.
If you are running PHP on a Unix box and want to
talk to MS Access on a Windows box you will need Unix
ODBC drivers. OpenLink Software has Unix-based ODBC
drivers that can do this. There is a free pilot program
where you can download an evaluation copy that doesn't
expire and prices start at $675 for the commercial
supported version.
Another alternative is to use an SQL server that
has Windows ODBC drivers and use that to store the
data, which you can then access from Microsoft Access
(using ODBC) and PHP (using the built in drivers), or
to use an intermediary file format that Access and PHP
both understand, such as flat files or dBase databases.
On this point Tim Hayes from OpenLink software
writes:
Using another database as an intermediary is not a good idea, when you can use ODBC from PHP straight to your database - i.e. with OpenLink's drivers. If you do need to use an intermediary file format, OpenLink have now released Virtuoso (a virtual database engine) for NT, Linux and other unix platforms. Please visit our website for a free download. |
One option that has proven successful is to use
MySQL and its MyODBC drivers on Windows and
synchronizing the databases. Steve Lawrence writes:
Install MySQL on your platform according to
instructions with MySQL. Latest available from
www.mysql.com (get it from your mirror!). No
special configuration required except when you set
up a database, and configure the user account, you
should put % in the host field, or the host name of
the Windows computer you wish to access MySQL with.
Make a note of your server name, username, and
password.
Download the MyODBC for Windows driver from
the MySQL site. Latest release is
myodbc-2_50_19-win95.zip (NT available too, as well
as source code). Install it on your Windows
machine. You can test the operation with the
utilities included with this program.
Create a user or system dsn in your ODBC
administrator, located in the control panel. Make
up a dsn name, enter your hostname, user name,
password, port, etc for you MySQL database
configured in step 1.
Install Access with a full install, this makes
sure you get the proper add-ins.. at the least you
will need ODBC support and the linked table
manager.
Now the fun part! Create a new access
database. In the table window right click and
select Link Tables, or under the file menu option,
select Get External Data and then Link Tables. When
the file browser box comes up, select files of
type: ODBC. Select System dsn and the name of your
dsn created in step 3. Select the table to link,
press OK, and presto! You can now open the table
and add/delete/edit data on your MySQL server! You
can also build queries, import/export tables to
MySQL, build forms and reports, etc.
Tips and Tricks:
You can construct your tables in Access and
export them to MySQL, then link them back in. That
makes table creation quick.
When creating tables in Access, you must have
a primary key defined in order to have write access
to the table in access. Make sure you create a
primary key in MySQL before linking in access
If you change a table in MySQL, you have to
re-link it in Access. Go to
tools add-ins linked table manager, cruise to
your ODBC DSN, and select the table to re-link from
there. you can also move your dsn source around
there, just hit the always prompt for new location
checkbox before pressing OK.
3. I upgraded to
PHP 4, and now mysql keeps telling me "Warning: MySQL:
Unable to save result set in ...". What's up?
Most likely what has happened is, PHP 4 was
compiled with the '--with-mysql' option, without
specifying the path to MySQL. This means PHP is using
its built-in MySQL client library. If your system is
running applications, such as PHP 3 as a concurrent
Apache module, or auth-mysql, that use other versions
of MySQL clients, then there is a conflict between the
two differing versions of those clients.
Recompiling PHP 4, and adding the path to MySQL to
the flag, '--with-mysql=/your/path/to/mysql'
usually solves the problem.
4. After
installing shared MySQL support, Apache dumps core as
soon as libphp4.so is loaded. Can this be
fixed?
If your MySQL libs are linked against pthreads this
will happen. Check using ldd. If they are, grab the
MySQL tarball and compile from source, or recompile
from the source rpm and remove the switch in the spec
file that turns on the threaded client code. Either of
these suggestions will fix this. Then recompile PHP
with the new MySQL libs.
5. Why do I
get an error that looks something like this: "Warning:
0 is not a MySQL result index in file on line
x " or "Warning: Supplied argument is not a
valid MySQL result resource in file on line
x ?
You are trying to use a result identifier that is
0. The 0 indicates that your query failed for some
reason. You need to check for errors after submitting a
query and before you attempt to use the returned result
identifier. The proper way to do this is with code
similar to the following:
$result = mysql_query("SELECT * FROM tables_priv"); if (!$result) { echo mysql_error(); exit; } |
$result = mysql_query("SELECT * FROM tables_priv") or die("Bad query: ".mysql_error()); |