java与MySQL数据库的连接
1.数据库的安装和建立参见上一篇博客中的第1,2步骤。(http://blog.csdn.net/nuptboyzhb/article/details/8043091)
或使用SQL语句
- # ubuntu Linux
- sudo mysql -u root -p
- #Windows 7(mysql.exe)
-
- create database testdb;
- use testdb;
- CREATE TABLE `name_table` (
- `_id` int(11) NOT NULL,
- `name` varchar(32) CHARACTER SET utf8,
- `age` int(11) NOT NULL,
- `work` varchar(32) CHARACTER SET utf8,
- `others` varchar(512) CHARACTER SET utf8 DEFAULT NULL,
- PRIMARY KEY (`_id`)
- ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
2.Eclipse的配置。
导入包mysql-connector-java-5.0.5-bin.jar
3.java代码的编写
[java code]
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.PreparedStatement;
- import java.sql.ResultSet;
- import java.sql.SQLException;
- public class helloworld {
- private Connection conn = null;
- PreparedStatement statement = null;
-
- void connSQL() {
- String urle = "jdbc:mysql://localhost:3306/testdb";//port:3306 database:testdb
- String username = "root";
- String password = "931706659";
- try {
- Class.forName("com.mysql.jdbc.Driver" );
- conn = DriverManager.getConnection(urle,username, password );
- }
-
- catch ( ClassNotFoundException cnfex ) {
- System.err.println(
- "装载 JDBC/ODBC 驱动程序失败。" );
- cnfex.printStackTrace();
- }
-
- catch ( SQLException sqlex ) {
- System.err.println( "无法连接数据库" );
- sqlex.printStackTrace();
- }
- }
-
-
- void deconnSQL() {
- try {
- if (conn != null)
- conn.close();
- } catch (Exception e) {
- System.out.println("关闭数据库问题 :");
- e.printStackTrace();
- }
- }
-
-
- ResultSet selectSQL(String sql) {
- ResultSet rs = null;
- try {
- statement = conn.prepareStatement(sql);
- rs = statement.executeQuery(sql);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return rs;
- }
-
-
- boolean insertSQL(String sql) {
- try {
- statement = conn.prepareStatement(sql);
- statement.executeUpdate();
- return true;
- } catch (SQLException e) {
- System.out.println("插入数据库时出错:");
- e.printStackTrace();
- } catch (Exception e) {
- System.out.println("插入时出错:");
- e.printStackTrace();
- }
- return false;
- }
-
- boolean deleteSQL(String sql) {
- try {
- statement = conn.prepareStatement(sql);
- statement.executeUpdate();
- return true;
- } catch (SQLException e) {
- System.out.println("插入数据库时出错:");
- e.printStackTrace();
- } catch (Exception e) {
- System.out.println("插入时出错:");
- e.printStackTrace();
- }
- return false;
- }
-
- boolean updateSQL(String sql) {
- try {
- statement = conn.prepareStatement(sql);
- statement.executeUpdate();
- return true;
- } catch (SQLException e) {
- System.out.println("插入数据库时出错:");
- e.printStackTrace();
- } catch (Exception e) {
- System.out.println("插入时出错:");
- e.printStackTrace();
- }
- return false;
- }
-
- void layoutStyle2(ResultSet rs) {
- System.out.println("-----------------");
- System.out.println("执行结果如下所示:");
- System.out.println("-----------------");
- System.out.println(" id" + "\t\t" + "name" +"\t\t" + "age" + "\t\t" +"work"+ "\t\t" + "others");
- System.out.println("-----------------");
- try {
- while (rs.next()) {
- System.out.println(rs.getInt("_id") + "\t\t"
- + rs.getString("name") + "\t\t"
- +rs.getInt("age") + "\t\t"
- + rs.getString("work")+ "\t\t"
- + rs.getString("others"));
- }
- } catch (SQLException e) {
- System.out.println("显示时数据库出错。");
- e.printStackTrace();
- } catch (Exception e) {
- System.out.println("显示出错。");
- e.printStackTrace();
- }
- }
-
- public static void main(String args[]) {
-
- helloworld h = new helloworld();
- h.connSQL();
- String s = "select * from name_table";
-
- String insert = "insert into name_table(_id,name,age,work,others) values("+15+",‘csdn‘,"+24+",‘M.S.‘,‘nupt‘)";
- String update = "update name_table set age =19 where name= ‘zhb‘";
- String delete = "delete from name_table where name= ‘csdn‘";
-
- if (h.insertSQL(insert) == true) {
- System.out.println("insert successfully");
- ResultSet resultSet = h.selectSQL(s);
- h.layoutStyle2(resultSet);
- }
- if (h.updateSQL(update) == true) {
- System.out.println("update successfully");
- ResultSet resultSet = h.selectSQL(s);
- h.layoutStyle2(resultSet);
- }
- if (h.insertSQL(delete) == true) {
- System.out.println("delete successfully");
- ResultSet resultSet = h.selectSQL(s);
- h.layoutStyle2(resultSet);
- }
- h.deconnSQL();
- }
- }
整个项目的源代码:http://download.csdn.net/detail/nuptboyzhb/4620059
4.实验结果
[image]