The Connection
An application
should call mysql_init(
)
before performing any other
operation. This method initializes a database handler used by many of
the functions—including the connection and
error
handling functions. In the above example, we created a handler in the
declaration:
MYSQL *connection, mysql;
The pointer to the handler, connection
, will
represent our actual connection once it is made; the allocated
handler, mysql
, represents a null connection until
we actually make the database connection. Our first step is to
initialize this handler through the mysql_init( )
function:
mysql_init(&mysql);
This function takes a reference to an allocated
null handler. The MySQL API
requires this hocus-pocus with a null handler to support operations
such as error handling that occur outside the context of a physical
database connection. The first function needing this handler is the
actual connection API: mysql_real_connect( )
.
Tip
At first glance over the API list, you may be tempted to use the
mysql_connect( )
function. The odd name of the
mysql_real_connect( )
function exists because it
is a replacement for the long-deprecated mysql_connect(
)
function. The old mysql_connect( )
provided compatibility for mSQL applications; you should never use it
in modern applications.
The mysql_real_connect(
)
function takes several arguments:
- null handler
The connection handler allocated and subsequently initialized through
mysql_init( )
.- host
The name of the machine on which the MySQL server ...
Get Managing & Using MySQL, 2nd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.