One of the Hibernate learning notes (JDBC Review-orm specification)

JDBC Review-orm specification

JDBC Operation steps

• Registering Database Drivers
  Class.forName ("Jdbcdriverclass")

Database	Driver Class	Source
Access	Sun.jdbc.odbc.JdbcOdbcDriver	In the JDK
Mysql	Com.mysql.jdbc.Driver	Download MySQL Driver pack
Oracle	Oracle.jdbc.driver.OracleDriver	Download the corresponding driver package
SQL Server	Com.microsoft.sqlserver.jdbc.SQLServerDriver	Download the corresponding driver package

In order to use the driver package, you need to add the downloaded driver package to the CLASSPATH

• Create a connection type Object
  Connection Connection = drivermanager.getconnection (Databaseurl,username,password);
  Access does not require the Username,password parameter

Database	URL pattern
Access	Jdbc:odbc:dataSource
Mysql	Jdbc:mysql://hostname/dbname
Oracle	Jdbc:oracle:thin: @hostname:p Ort#:oracledbsid (port# represents the port number, ORACLEDBSID is the database name of the location database)
SQL Server	Jdbc:sqlserver://hostname:port;databasename= database name

• Get Statement type Object
  Statement Statement = Connection.createstatement ()

• Perform a query or update
  You can use Executeupdate () to execute SQL DDL (data definition Language) or UPDATE statements
  Query statements can be executed using executequery ()

• Working with ResultSet type objects
  Query results exist in resultset, you can use next () to move the cursor to the next line, using getxxx (XXX for data type) to get the column values of the current row

• Freeing resources
  Connection.close ()

Orm

    全称Object/Relation Mapping,对象/关系映射    ORM框架：完成面向对象的程序设计语言到关系数据库的映射    目前的产品很多，如：Apache组织下的OJB，Oracle的TopLink，JDO，JPA等    优点：提高生产效率，可维护性

One of the Hibernate learning notes (JDBC Review-orm specification)