Java使用JDBC连接MYSQL数据库增删改查示例
JDBC连接MYSQL数据库：
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
- rs.absolute() //绝对位置，负数表示从后面数
- rs.first()第一条
- rs.last()最后一条
- rs.previoust()前一条
- rs.next()后一条
- rs.beforeFirst()第一条之前
- rs.afterLast()最后之后
- rs.isFirst(),rs.isLast(),rs.isBeforeFirst(),rs.isAfterLast