MySQL的簡單操作方法：Statement、PreparedStatement，

MySQL的簡單操作方法：Statement、PreparedStatement，

（1）串連mysql的工具類：DBUtil.java

package com.xuliugen.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class DBUtil {    public static Connection getConn() {        Connection conn = null;        try {            Class.forName("com.mysql.jdbc.Driver");            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/你的資料庫名稱", "你的帳號", "你的密碼");        } catch (ClassNotFoundException e) {            e.printStackTrace();        } catch (SQLException e) {            e.printStackTrace();        }        return conn;    }    public static PreparedStatement prepareStmt(Connection conn, String sql) {        PreparedStatement pstmt = null;        try {            pstmt = conn.prepareStatement(sql);        } catch (SQLException e) {            e.printStackTrace();        }        return pstmt;    }    public static ResultSet executeQuery(Statement stmt, String sql) {        ResultSet rs = null;        try {            rs = stmt.executeQuery(sql);        } catch (SQLException e) {            e.printStackTrace();        }        return rs;    }    public static void close(Connection conn, Statement stmt,            PreparedStatement preStatement, ResultSet rs) {        if (conn != null) {            try {                conn.close();            } catch (SQLException e) {                e.printStackTrace();            }            conn = null;        }        if (stmt != null) {            try {                stmt.close();            } catch (SQLException e) {                e.printStackTrace();            }            stmt = null;        }        if (preStatement != null) {            try {                preStatement.close();            } catch (SQLException e) {                e.printStackTrace();            }            preStatement = null;        }        if (rs != null) {            try {                rs.close();            } catch (SQLException e) {                e.printStackTrace();            }            rs = null;        }    }}

（2）使用preparedStatement插入資料的資料庫：

public boolean saveComment(Comment comment) {        Connection connection = DBUtil.getConn();        String sql = "insert into comment values (null,?,?,?,?)";        PreparedStatement preparedStatement = null;        boolean flag = false;        try {            preparedStatement = connection.prepareStatement(sql);            preparedStatement.setString(1, comment.getCommenttext() + "");            preparedStatement.setString(2, comment.getCommenttime() + "");            preparedStatement.setString(3, comment.getUserid() + "");            preparedStatement.setString(4, comment.getArticleid() + "");            int isOk = preparedStatement.executeUpdate();            if (isOk > 0) {                return !flag;            } else {                return flag;            }        } catch (SQLException e) {            e.printStackTrace();        }        DBUtil.close(connection, null, preparedStatement, null);        return flag;    }

（3）使用preparedStatement選擇資料，讀取資料：

public List<Comment> getCommentDetail(int userid, int articleid) {        Connection connection = DBUtil.getConn();        String sql = "select * from comment c where c.userid=? and c.articleid=?";// 編寫sql語句，第一個欄位不需要插入，是自動增加的        PreparedStatement preparedStatement = null;        List<Comment> commentList = new ArrayList<Comment>();        try {            preparedStatement = connection.prepareStatement(sql);            preparedStatement.setInt(1, userid);            preparedStatement.setInt(2, articleid);            //這裡的產訊不需要傳入sql語句            ResultSet rs = preparedStatement.executeQuery();            // 判斷是否為空白            if (rs.next()) {                while (rs.next()) {// 將資訊迭代到list中                    Comment comment = new Comment();                    comment.setCommentid(rs.getInt("commentid"));                    comment.setCommenttext(rs.getString("commenttext"));                    comment.setCommenttime(rs.getString("commenttime"));                    comment.setUserid(rs.getInt("userid"));                    comment.setArticleid(rs.getInt("articleid"));                    commentList.add(comment);                }            } else {                return null;            }        } catch (SQLException e) {            e.printStackTrace();        }        DBUtil.close(connection, null, preparedStatement, null);        return commentList;    }

（4）使用Statement操作資料庫：

public List<Article> getArticleMessage() {        Connection connection = DBUtil.getConn();        String sql = "select * from article";// 編寫sql語句，第一個欄位不需要插入，是自動增加的        Statement statement = null;        List<Article> articleList = new ArrayList<Article>();        try {            statement = connection.createStatement();            ResultSet rs = statement.executeQuery(sql);            //判斷是否為空白            if (rs.next()) {                while (rs.next()) {//將資訊迭代到list中                    Article article = new Article();                    article.setTitle(rs.getString("title"));                    article.setContext(rs.getString("context"));                    article.setArticleTime(rs.getString("articletime"));                    article.setUserid(rs.getInt("userid"));                    article.setArticleid(rs.getInt("articleid"));                    articleList.add(article);                }            } else {                return null;            }        } catch (SQLException e) {            e.printStackTrace();        }        DBUtil.close(connection, statement, null, null);        return articleList;    }