JDBC连接Oracle实现增、删、改操作

• • • jsp页面的form表单
    • AddMentaction实现向数据新增数据操作
    • DeleteMent删除操作
    • UpdateMent修改操作

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最近在做一个练习项目“在线考试系统”，在将整体架构搭好然后将任务分配给组员以后，自己完成自己部分的功能，在自己所完成的功能当初，涉及了一个jsp页面写入数据，将数据提交保存至数据库，可对数据实现增、删、改、查等操作，将其中主要功能实现以作总结。

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jsp页面的form表单

<form method="post" action="AddMent.action">
    <input name="deptid" type="text">
    <input type="text" name="deptid"  placeholder="请输入部门编号" />
    <input type="text" name="deptname"  placeholder="请输入部门名称" />
    <input type="text" name="deptnews"  placeholder="请输入部门信息" />
    <button class="button" type="submit"> 提交</button>

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AddMent.action实现向数据新增数据操作

@WebServlet(value="/System/AddMent.action")
public class AddMentDao extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        doPost(req, resp);
        super.doGet(req, resp);
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
/*      String uname = req.getParameter("uname");
        String qx = req.getParameter("qx");*/
        Connection con=null;
        Statement st=null;
        try {
            //1.加载驱动
            Class.forName("oracle.jdbc.driver.OracleDriver");
            //2.建立数据库连接
            con= DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:jredu","OnlineTest","Jredu12345");
            //3.获取执行sql语句的平台
            st= con.createStatement();
            String deptid = req.getParameter("deptid");
            String deptname = req.getParameter("deptname");
            String deptnew = req.getParameter("deptnew");
            //4.执行sql语句插入数据
            String sql = "INSERT INTO dept(deptid, deptname, deptnew) "
                    + " VALUES(?, ?, ?)";
             PreparedStatement pstmt = con.prepareStatement(sql);
             pstmt.setString(1, req.getParameter("deptid"));
             pstmt.setString(2, req.getParameter("deptname"));
             pstmt.setString(3, req.getParameter("deptnew"));
             pstmt.execute();
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            //关闭st
            if(st != null){
                try {
                    st.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            //关闭con
            if(con != null){
                try {
                    con.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

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DeleteMent删除操作

@WebServlet(value="/System/Delete.Action")
public class DeleteMent extends HttpServlet{
        /**
         * 添加试题
         */
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException {
            // TODO Auto-generated method stub
            doPost(req, resp);
            super.doGet(req, resp);
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException {
            // TODO Auto-generated method stub
            String deptname = req.getParameter("deptname");
            Connection con=null;
            Statement st=null;
            try {
                //1.加载驱动
                Class.forName("oracle.jdbc.driver.OracleDriver");
                //2.建立数据库连接
                con= DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:jredu","OnlineTest","Jredu12345");
                //3.获取执行sql语句的平台
                st= con.createStatement();
                //4.执行sql语句插入数据
                String sql = "DELETE FROM dept WHERE deptname=?";
                PreparedStatement pstmt = con.prepareStatement(sql);
                pstmt.setString(1, req.getParameter("deptname"));
                pstmt.execute();
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                //关闭st
                if(st != null){
                    try {
                        st.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                //关闭con
                if(con != null){
                    try {
                        con.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        }
}

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UpdateMent修改操作

@WebServlet(value="/System/Update.action")
public class UpdateMent extends HttpServlet{
        /**
         * 添加试题
         */
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException {
            // TODO Auto-generated method stub
            doPost(req, resp);
            super.doGet(req, resp);
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException {
            // TODO Auto-generated method stub
            Connection con=null;
            Statement st=null;
            try {
                //1.加载驱动
                Class.forName("oracle.jdbc.driver.OracleDriver");
                //2.建立数据库连接
                con= DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:jredu","OnlineTest","Jredu12345");
                //3.获取执行sql语句的平台
                st= con.createStatement();
                String deptid = req.getParameter("deptid");
                String deptname = req.getParameter("deptname");
                String deptnew = req.getParameter("deptnew");
                String sql="update dept set deptid=?,deptname=?,deptnew=?"+
                         "where deptid=?";
                 PreparedStatement pstmt = con.prepareStatement(sql);
                 pstmt.setString(1, req.getParameter("deptid"));
                 pstmt.setString(2, req.getParameter("deptname"));
                 pstmt.setString(3, req.getParameter("deptnew"));
                 pstmt.setString(4, req.getParameter("deptid"));
                 pstmt.execute();
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                //关闭st
                if(st != null){
                    try {
                        st.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                //关闭con
                if(con != null){
                    try {
                        con.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        }
}

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