JDBC 数据删除，增加，及数据库信息查询

ゞ浴缸里的玫瑰 2022-12-17 10:59 176阅读 0赞

package com.dgd.test;
    import java.sql.*;
    public class DBTest { 
        //mysql驱动包名
        private static final String DRIVER_NAME = "com.mysql.jdbc.Driver";
        //数据库连接地址
        // ?useSSL=false不校验ssl证书
        // jdbc:mysql://这是协议，localhost:3306这是地址和端口，test这是数据库
        private static final String URL = "jdbc:mysql://localhost:3306/test?useSSL=false";
        //用户名,更换成你自己的用户名，此处为root用户
        private static final String USER_NAME = "root";
        //密码，更换成你自己设定的密码，此处为:123456
        private static final String PASSWORD = "123456";
    
        public static void main(String[] args) { 
            Connection connection = null;
            try { 
                //加载mysql的驱动类
                Class.forName(DRIVER_NAME);
                //获取数据库连接
                connection = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
    
                DatabaseMetaData dbmd = connection.getMetaData();
                System.out.println("数据库名：/t"+dbmd.getDatabaseProductName());
                System.out.println("数据库产品版本：/t"+dbmd.getDatabaseProductVersion());
                System.out.println("驱动版本：/t"+dbmd.getDriverVersion());
                // 获取数据库服务器用作类别和表名之间的分隔符 如test.user
                System.out.println("数据库和表分隔符:\t"+dbmd.getCatalogSeparator());
                // 获取数据库名称
                ResultSet rs = dbmd.getCatalogs();
                while (rs.next()) { 
                    System.out.println("数据库名称:\t"+rs.getString(1));
                }
    
                Boolean isDel = true;
                if(true){ 
    				//打断后面执行语句
                }else  if(isDel){ 
                    String sql = "delete from user where id = ?;";
                    PreparedStatement prst = connection.prepareStatement(sql);
                    for (int i = 0; i < 5; i++) { 
                        prst.setInt(1,i);
                        prst.execute();
                    }
                    prst.setInt(1,20);
                    prst.execute();
                    prst.close();
                }else { 
                    String sql = "insert into user values(null,?,?,?,?)";
                    PreparedStatement prst = connection.prepareStatement(sql);
                    for (int i = 0; i < 5; i++) { 
                        prst.setString(1, "提莫lam"+i);
                        prst.setFloat(2, i+10);
                        prst.setInt(3, i);
                        prst.setInt(4, i+100);
                        prst.execute();
                    }
                    prst.close();
                }
    
            } catch (Exception e) { 
                e.printStackTrace();
            } finally { 
                if (connection != null) { 
                    try { 
                        connection.close();
                    } catch (SQLException e) { 
                        e.printStackTrace();
                    }
                }
            }
        }
    }