时间:2021-07-01 10:21:17 帮助过:22人阅读
代码区域:
package com.oracle.jdbc.demo1; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class JDBCDemo { //四个属性(四个常量的字符串) /* jdbcName url user password */ private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //获得conn就表示获取了数据库的连接 System.out.println("连接数据库成功"); } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
2.在java中向数据库添加数据
第一种方法:添加数据
代码区域:
package com.oracle.jdbc.demo2; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class JDBCAdd { private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、PreparedStatement、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //增加数据的操作 String name="田雨"; String sex="女"; String sql="insert into person values(null,‘"+name+"‘,‘"+sex+"‘)"; PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句 int i=pst.executeUpdate(); //返回成功插入数据的行数 System.out.println("成功添加了"+i+"条记录"); } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
第二中方法:添加数据
代码区域:
package com.oracle.jdbc.demo2; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class JDBCAdd2 { private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、PreparedStatement、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //增加数据的操作 String name="田雨2"; String sex="女"; String sql="insert into person values(null,?,?)"; PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句 pst.setString(1, name); //填充第1个问好 pst.setString(2, sex); //填充第2个问好 int i=pst.executeUpdate(); //返回成功插入数据的行数 System.out.println("成功添加了"+i+"条记录"); } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
3.在java中修改数据库的内容
代码区域:
package com.oracle.jdbc.demo3; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class JDBCModify { private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、PreparedStatement、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //修改数据的操作 int id=2; String name="王希宝"; String sex="男"; String sql="update person set name=?,sex=? where id=?"; PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句 pst.setString(1, name); //填充第1个问好 pst.setString(2, sex); //填充第2个问好 pst.setInt(3, id); int i=pst.executeUpdate(); //返回成功修改数据的行数 System.out.println("成功修改了"+i+"条记录"); } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
4.在java中删除数据库的内容
代码区域:
package com.oracle.jdbc.demo4; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class JDBCDel { private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、PreparedStatement、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //删除数据的操作 int id=2; String sql="delete from person where id=?"; PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句 pst.setInt(1, id); int i=pst.executeUpdate(); //返回成功删除数据的行数 System.out.println("成功删除了"+i+"条记录"); } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
5.在java中查看数据库的内容
代码区域:
package com.oracle.jdbc.demo5; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class JDBCFindAll { private static final String jdbcName="com.mysql.jdbc.Driver"; private static final String url="jdbc:mysql://127.0.0.1:3306/emp_dept"; private static final String user="root"; private static final String password="123456"; /* * 一个类(DriverManeger)四个接口(Connection、PreparedStatement、ResultSet、) * */ public static void main(String[] args) { // TODO Auto-generated method stub Connection conn=null; try { Class.forName(jdbcName); conn=DriverManager.getConnection(url, user, password); //查询数据的操作 String sql="select id,name,sex from person"; PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句 ResultSet rs=pst.executeQuery(); while(rs.next()){ int id=rs.getInt("id"); String name=rs.getString("name"); String sex=rs.getString("sex"); System.out.println(id+" "+name+" "+sex); } } catch (Exception e) { e.printStackTrace(); } finally { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
在java中对数据库进行增删改查
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