PHP has numerous functions for connecting to Oracle databases, which is a plus because if you've spent the money to purchase an Oracle database, you'll want to be able to connect to it using this new-fangled programming language that's all the rage. The PHP Manual has the definitive list of PHP -> Oracle connectivity functions, however, you only need a few in order to make a simple connection and select some data:

OCILogon - opens a connection to Oracle; requires that the environment variable ORACLE_SID has been set and that you have a valid username and password.

OCIParse - parses a SQL statement.

OCIExecute - executes the SQL statement.

OCINumCols - gets the number of columns used in the SQL statement.

OCIFetch - gets the next row in the result of a SQL statement and places it in a results buffer.

OCIResult - gets the value of the named column, in the current result row.

OCIFreeStatement - frees the resources in use by the current statement.

OCILogoff - closes the connection to Oracle.

Just for argument's sake, let's pretend that an Oracle database is already installed on your system, for which you have a valid username and password. Let's also assume that you've created a table on that database, called COFFEE_INVENTORY. The COFFEE_INVENTORY table has three columns: COFFEE_NAME, ROAST_TYPE and QUANTITY.

The rows in the COFFEE_INVENTORY table could be populated with data such as:

French Roast,dark,18

Kenya,medium,6

Ethiopian Harrar,medium,35

Sumatra,dark,8

Columbian,light,12

Now, let's do some PHP. Before you begin, you must have a valid username and password for the server named in ORACLE_SID (the server ID environment variable). Then, start your PHP code by creating a connection variable:

Test that a connection was established, and if it wasn't, print an error message and exit the program:

If you have made it through the connection test, the next step is to create the SQL statement. Using the COFFEE_INVENTORY table, suppose you want to view your inventory, including the name of the coffee and the roast type, with the highest number of bags listed first. Create a variable that holds your SQL statement:

Next, use the OCIParse function to parse the statement in the context of your database connection:

The next step is to execute the statement:

Now it's time to get the results; use the OCIFetch function within a while statement, to get each row in your results:

The code within the while loop will continue to execute as long as there are rows in the result set. So, let's put some code inside the loop!

For each row in your result set, you will have a number of columns. The number of columns is important to know, as you'll use this number to step incrementally through the data. Before your while loop, add this variable to get the number of columns used in your SQL statement:

Return to your while loop, and place the following for expression within it, to step through your result row:

For as long as $i is less than the number of columns in the result row, the loop will execute. This loop will be repeated for every row in the result set.

You'll probably want to print the results in a simple HTML table. Step back and place this statement before the while loop begins, to open the table tag and create the row headings:

Now, add some code within the while loop, to start the table row that will hold the data from the result row:

Next, add a line within your for statement, to enclose each individual piece of data within inside a table cell:

Before closing the while loop, close the table row:

The new while loop should look something like this:

After the while loop, close the HTML table:

Finally, you'll want to free up the resources used to perform the query, and close the database connection. Failing to do so could cause memory leaks and other nasty resource-hogging things to occur.

The full script to perform a simple connection and data selection from an Oracle database could look something like this:

Please see the PHP Manual for additional Oracle functions (for which there are many, and they can get very complex!), and try using your own tables and SQL statements instead of the examples above.