hostname (for non ODBC), and a database name. So complete DSN syntax 

would be 

driver name://username:password@hostname/databasename

PEAR DB has a database driver for MySQL called 

mysql

, it can be used to 

create a connection. So DSN for connecting to our database would be

mysql://itso:itso@localhost/itsodb

PEAR DB does not provide a driver for DB2 UDB. But it supports DB2 UDB 

using ODBC driver. SO DSN for DB2 UDB would be

odbc(db2)://itso:itso/itsodb2

You can optionally provide second parameter to 

connect()

 which specifies 

whether you want your connection to be persistent or non persistent. 

Example 7 35 shows the PEAR DB database connect for MySQL and the 

DB2 conversion code.

Example 7 35   PEAR DB database connection for DB2 UDB and MySQL

include( /usr/local/lib/php/PEAR/DB.php );

\\ MySQL database connection with DSN='mysql//itso:itso@localhost/itsodb2'

$conn = DB::connect( mysql//itso:itso@itsodb2 );

\\ DB2 UDB database connection with DSN='odbc(db2)//itso:itso/itsodb2'

$conn = DB::connect( odbc(db2)://itso:itso@itsodb2 );

if(DB::isError($conn))

print "connection error : ".$conn >getMessage();

Process query

The query can be executed by calling 

query()

 method on the connection 

object. It takes the SQL statement as an input parameter and returns the 

results. The results can be used in three modes depending on the SQL 

statement and statement's final status:

  Error case

In case an error occurs while executing the SQL statement you can use 

return object for getting error message using the method 

getMessage()

. 

This code does not change with the change in database, so MySQL and 

DB2 UDB code is same. Example 7 36 shows the usage of the result 

object for getting the error message.

  Result set

If your SQL statement was a query statement, the return object can be 

used to fetchthe result set using the fetchRow variable of the return object. 

Again, MySQL and DB2 UDB database differences do not cause any 

 Chapter 7. Application porting 

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