Class MySQLDBImpl implements DBOperations
	{
		private String dbUrl;//simple type
	}
	
	class UserService
	{
		private DBOperation dbop;
	}
	
	<bean id="b1" class="com.practise.MySqlDBImpl">
		<property name="dbUrl" value ="jdbc:mysql://localhost:3306"/>
	</bean>
	
	<bean id="b2" class="com.practise.UserService">
		<property name="dbop" ref="b1" />
	</bean>

• It helps you to interact with any Relational Database systems like Oracle,Mysql,Derby,Sybase and so on

• It gives you a configuration class (DriverManagerDataSource) to configure datasource information like username,password,url,driverClass,this class establishes database connection object for you using the configuration in XML

• It gives you a template class (JdbcTemplate) that uses DriverManagerDataSource to perform CRUD operations

It has 4 properties -username -password -url -driverclassName

It has a property called datasource which is referencing DriverManagerDataSource

• Using Derby so configure it
• Project with dependencies - spring-context,spring-jdbcm derby-client
  • Employee class - id ,name & salary
• Interface EmployeeDao
• Implementation EmployeeDaoImpl
• Employee Service Class
• XML Configuration
  • DriverManagerDataSource - username , password, url, driverClassName
  • JDBC Template - datasource
  • EmployeeDaoImpl
  • EmployeeService
• Main class that acts like Conroller

• update(sqlQuery,args)
• queryForObject(sqlQuery,rowMapperObject,Object),Example :- sqlQuery="select * from employee where id = ?"
• query(sqlQuery,rowMapperObject)
• update : It is used to run insert , update & delete types of query
• queryForObject : It is used to run select query that can return one result, mainly used when you wan an object with a particulae id
• query : It is also used to run select quey but it returns multiple records , mainly used when you want multiple objects for a query.
• rowMapperObject : It is a class that implements RowMapper interface that takes care of converting sql records to java object , it has one method map(int rowNum,ResultSet rs) When select query is triggered a one or more rows will be returned which is handled by ResultSet & rowNum gives index number for each ResultSet, on each map() invocation we can expect one java object.