HTML数据保存 Oracle CLOB大对象操作

最新推荐文章于 2021-10-03 20:29:27 发布

原创最新推荐文章于 2021-10-03 20:29:27 发布 · 1.7k 阅读

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#oracle #html #exception #sql #user #string

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本文介绍了一个关于用户信息增删改查的具体实现案例，包括从数据库中获取指定ID的用户信息以及添加新用户到数据库的过程。该示例使用了Java语言，并通过SQL语句与数据库进行交互。

public User getUser(int id) throws ClassNotFoundException, SQLException { Connection conn = DBConnection.getConnection(); User user = new User(); try { Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("select * from userinfo where id ="+id); if (rs.next()) { user.setId(rs.getInt("id")); user.setUsername(rs.getString("username")); user.setUserpass(rs.getString("userpass")); java.sql.Clob clob = rs.getClob("userinfo"); Reader inStream = clob.getCharacterStream(); char[] c = new char[(int) clob.length()]; inStream.read(c); String data = new String(c); user.setUserinfo(data); inStream.close(); } rs.close(); stmt.close(); } catch (Exception e) { System.out.println(" Error："+e.getMessage()); }finally{ conn.close(); } return user; } public int addUser(User user) throws ClassNotFoundException, SQLException { Connection conn = DBConnection.getConnection(); String sql=""; int id = 0; try { PreparedStatement pstmt=null; ResultSet rst=null; conn.setAutoCommit(false); oracle.sql.CLOB clob=null; sql = "select sequenceDemo.nextval from dual"; pstmt = conn.prepareStatement(sql); rst=pstmt.executeQuery(); if(rst.next()){ id = (int)rst.getInt(1); } pstmt.close(); //添加null Clob sql = "insert into userinfo(id,username,userpass,userinfo) values (?,?,?,empty_clob())"; pstmt = conn.prepareStatement(sql); pstmt.setInt(1, id); pstmt.setString(2, user.getUsername()); pstmt.setString(3, user.getUserpass()); pstmt.executeUpdate(); pstmt.close(); //获取修改--锁 sql = "select userinfo from userinfo where id= ? for update"; pstmt = conn.prepareStatement(sql); pstmt.setInt(1, id); rst=pstmt.executeQuery(); if(rst.next()){ clob=(CLOB)rst.getClob(1); } pstmt.close(); //获得clob对象的输出流 PrintWriter pw=new PrintWriter(clob.getCharacterOutputStream()); pw.write(user.getUserinfo()); pw.flush(); //更新clob对象 sql="UPDATE userinfo set userinfo =? where id=?"; pstmt=conn.prepareStatement(sql); pstmt.setClob(1, clob); pstmt.setInt(2, id); pstmt.executeUpdate(); conn.commit(); pw.close(); pstmt.close(); }catch (Exception e) { System.out.println(" Error："+e.getMessage()); }finally{ conn.close(); } return id; }