What are the steps involved for
making a connection with a database or how do you connect to a database?
a)
Loading the driver : To load the driver, Class. forName() method is used.
Class. forName(”sun. jdbc. odbc. JdbcOdbcDriver”); When the driver is loaded,
it registers itself with the java. sql. DriverManager class as an available
database driver. b) Making a connection with database: To open a connection to
a given database, DriverManager. getConnection() method is used. Connection con
= DriverManager. getConnection (”jdbc:odbc:somedb”, “user”, “password”); c)
Executing SQL statements : To execute a SQL query, java. sql. statements class
is used. createStatement() method of Connection to obtain a new Statement
object. Statement stmt = con. createStatement(); A query that returns data can
be executed using the executeQuery() method of Statement. This method executes
the statement and returns a java. sql. ResultSet that encapsulates the
retrieved data: ResultSet rs = stmt. executeQuery(”SELECT * FROM some table”);
d) Process the results : ResultSet returns one row at a time. Next() method of
ResultSet object can be called to move to the next row. The getString() and
getObject() methods are used for retrieving column values: while(rs. next()) {
String event = rs. getString(”event”); Object count = (Integer) rs.
getObject(”count”);
