数据库操作.pptx

Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,#,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Logo,#,数据库操作,本讲大纲,：,1,、连接数据库,支持网站：,www.,mrbccd,.com,2,、向数据库发送,SQL,语句,3,、处理查询结果集,4,、顺序查询,5,、模糊查询,6,、预处理语句,7,、添加、修改、删除记录,连接数据库,要访问数据库，首先要加载数据库的驱动程序（只需要在第一次访问数据库时加载一次），然后每次访问数据时创建一个,Connection,对象，之后执行操作数据库的,SQL,语句，最后在完成数据库操作后销毁前面创建的,Connection,对象，释放与数据库的连接。,向数据库发送,SQL,语句,实例,20.5,中的,getConnection(),方法只是获取与数据库的连接，要执行,SQL,语句首先要获得,Statement,类对象。通过实例,20.5,创建的连接数据库对象,con,的,createStatement(),方法可获得,Statement,对象。,处理查询结果集,有了,Statement,对象以后，可调用相应的方法实现对数据库的查询和修改，并将查询的结果集存放在,ResultSet,类的对象中。,顺序查询,ResultSet,类的,next(),方法的返回值是,boolean,类型的数据，当游标移动到最后一行之后会返回,false,。下面的实例就是将数据表,tb_emp,中的全部信息显示在控制台上。,模糊查询,SQL,语句中提供了,LIKE,操作符用于模糊查询，可使用“,%”,来代替,0,个或多个字符，使用下划线“,_”,来代替一个字符。例如，在查询姓张的同学的信息时，可使用以下,SQL,语句：,select*from tb_stu where name like,张,%,预处理语句,向数据库发送一个,SQL,语句，数据库中的,SQL,解释器负责把,SQL,语句生成底层的内部命令，然后执行该命令，完成相关的数据操作。如果不断地向数据库提交,SQL,语句，肯定会增加数据库中,SQL,解释器的负担，影响执行的速度。,添加、修改、删除记录,可以通过,SQL,语句对数据执行添加、修改和删除操作。可通过,PreparedStatement,类的指定参数动态地对数据表中原有数据进行修改操作，并通过,executeUpdate(),方法执行更新语句。,Thank you,还有什么疑问可以到,www.,mrbccd,.com,提出,也可以以发送邮件到,mingrisoft,mingrisoft,.com,