- import java.sql.Connection;
- import java.sql.DriverManager;
- public class Mysql {
- public static void main(String arg[]) {
- try {
- Connection con = null; //定义一个MYSQL链接对象
- Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动
- con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
- System.out.print("yes");
- } catch (Exception e) {
- System.out.print("MYSQL ERROR:" + e.getMessage());
- }
- }
- }
Class.forName("com.mysql.jdbc.Driver").newInstance(); 我们链接的是MYSQL数据库,所以需要一个MYSQL的数据库驱动,如果你的环境中没有安装, 可以下载:mysql-connector-java-5.1.17-bin.jar JAR包,然后放进jdk1.6.0_37\jre\lib\ext 重启eclispe 就可以在JRE系统库中看到。
con = DriverManager.getConnection;("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); 是链接数据库的语句, 返回Connection con;对象。参数格式:("jdbc:mysql://ip:端口/数据库名称", 用户名,密码)
写入一条数据
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.ResultSet;
- import java.sql.Statement;
- public class Mysql {
- /**
- * 入口函数
- * @param arg
- */
- public static void main(String arg[]) {
- try {
- Connection con = null; //定义一个MYSQL链接对象
- Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动
- con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
- Statement stmt; //创建声明
- stmt = con.createStatement();
- //新增一条数据
- stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");
- ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");
- int ret_id;
- if (res.next()) {
- ret_id = res.getInt(1);
- System.out.print(ret_id);
- }
- } catch (Exception e) {
- System.out.print("MYSQL ERROR:" + e.getMessage());
- }
- }
- }
stmt.executeUpdate INSERT; DELETE; UPDATE;语句都用executeUpdate函数来操作 stmt.executeQuery SELECT;语句都用stmt.executeQuery函数来操作 ResultSet res = stmt.executeQuery;("select LAST;_INSERT_ID()"); 查询最后插入数据的ID号,返回ResultSet res;对象
删除和更新数据
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.ResultSet;
- import java.sql.Statement;
- public class Mysql {
- /**
- * 入口函数
- * @param arg
- */
- public static void main(String arg[]) {
- try {
- Connection con = null; //定义一个MYSQL链接对象
- Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动
- con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
- Statement stmt; //创建声明
- stmt = con.createStatement();
- //新增一条数据
- stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");
- ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");
- int ret_id;
- if (res.next()) {
- ret_id = res.getInt(1);
- System.out.print(ret_id);
- }
- //删除一条数据
- String sql = "DELETE FROM user WHERE id = 1";
- long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作,如果大于0,则记录删除的条数
- System.out.print("DELETE:" + deleteRes);
- //更新一条数据
- String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";
- long updateRes = stmt.executeUpdate(updateSql);
- System.out.print("UPDATE:" + updateRes);
- } catch (Exception e) {
- System.out.print("MYSQL ERROR:" + e.getMessage());
- }
- }
- }
删除和更新数据都使用stmt.executeUpdate函数。 删除和更新数据都会返回一个Long的结果,如果为0,则删除或者更新失败,如果大于0则是操作删除的记录数
查询语句
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.ResultSet;
- import java.sql.ResultSetMetaData;
- import java.sql.Statement;
- public class Mysql {
- /**
- * 入口函数
- * @param arg
- */
- public static void main(String arg[]) {
- try {
- Connection con = null; //定义一个MYSQL链接对象
- Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动
- con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
- Statement stmt; //创建声明
- stmt = con.createStatement();
- //新增一条数据
- stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");
- ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");
- int ret_id;
- if (res.next()) {
- ret_id = res.getInt(1);
- System.out.print(ret_id);
- }
- //删除一条数据
- String sql = "DELETE FROM user WHERE id = 1";
- long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作,如果大于0,则记录删除的条数
- System.out.print("DELETE:" + deleteRes);
- //更新一条数据
- String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";
- long updateRes = stmt.executeUpdate(updateSql);
- System.out.print("UPDATE:" + updateRes);
- //查询数据并输出
- String selectSql = "SELECT * FROM user";
- ResultSet selectRes = stmt.executeQuery(selectSql);
- while (selectRes.next()) { //循环输出结果集
- String username = selectRes.getString("username");
- String password = selectRes.getString("password");
- System.out.print("\r\n\r\n");
- System.out.print("username:" + username + "password:" + password);
- }
- } catch (Exception e) {
- System.out.print("MYSQL ERROR:" + e.getMessage());
- }
- }
- }
查询语句使用stmt.executeQuery函数
来源: http://www.phpxs.com/code/1002042/