package com; import java.sql.*; public class DB { public Connection conn = null; public Statement stmt = null; public ResultSet rs = null; String url = "jdbc:mysql://localhost:3306/subway?useSSL=false&serverTimezone=UTC"; String username = "root"; String password = "1506583922"; public DB(){ try{ Class.forName("com.mysql.cj.jdbc.Driver"); conn = DriverManager.getConnection(url,username,password); stmt = conn.createStatement(); }catch(SQLException se){ // 处理 JDBC 错误 se.printStackTrace(); }catch(Exception e){ // 处理 Class.forName 错误 e.printStackTrace(); } } public void close(){ try { if (rs!=null){ rs.close(); } if (stmt!=null){ stmt.close(); } if (conn!=null){ conn.close(); } } catch (SQLException e) { throw new RuntimeException(e); } } }
package com; import dao.Sub; import java.sql.PreparedStatement; import java.sql.SQLException; public class DBC { public void CreateTable(){ Sub sub =new Sub(); PreparedStatement preparedStatement=null; try { DB db = new DB(); String sql ="CREATE TABLE IF NOT EXISTS `linktable`(" + "`Id` INT UNSIGNED AUTO_INCREMENT ," + "`Alink` VARCHAR(255) NOT NULL ," + "`Blink` VARCHAR(255) NOT NULL ," + "`Clink` VARCHAR(255) NOT NULL ," + "`Tname` VARCHAR(255) NOT NULL ," + "PRIMARY KEY(`Id`)" + ")ENGINE=INNODB DEFAULT CHARSET=utf8"; preparedStatement=db.conn.prepareStatement(sql); preparedStatement.executeUpdate(); db.close(); } catch (SQLException e) { e.printStackTrace(); } finally{ } try { DB db = new DB(); String b = "linktable"; String sqc = "SELECT * FROM " + b ; preparedStatement=db.conn.prepareStatement(sqc); preparedStatement.executeQuery(); while (db.rs.next()){ String equ = String.valueOf(db.rs.next()); for (int i = 0; i < 1; i++) { } } db.close(); }catch (SQLException e){ e.printStackTrace(); }finally { } } public void InsertFull(String table_name,String Id,String Alink,String Blink,String Clink,String Tname){ DB db = new DB(); PreparedStatement preparedStatement=null; try { String sql = "INSERT INTO "+ table_name + " (Id,Alink,Blink,Clink,Tname) values (?,?,?,?,?)"; preparedStatement=db.conn.prepareStatement(sql); preparedStatement.setString(1,Id); preparedStatement.setString(2,Alink); preparedStatement.setString(3,Blink); preparedStatement.setString(4,Clink); preparedStatement.setString(5,Tname); preparedStatement.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally{ } } }
标签:总结,preparedStatement,String,DB,每日,db,3.21,null,public From: https://www.cnblogs.com/louwangshayu/p/17241248.html