第一部分数据的增删改查。
@1 查看表的结构。
DESC student studentt为数据库
@2 增一条记录。
@3改记录
@4删除记录
#查表的结构
DESC student
SELECt *FROM student;
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1001, '毛毛', '男', 12);
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1002, '毛二', '男', 30);
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1003, '胡滨', '男', 20);
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1004, '集合', '男', 20);
DESC studenta;
INSERT INTO `students`.`studenta`(`stuId`, `stuSex`, `stuHeight`, `stuAge`) VALUES (1008, '674', 56, '79');
INSERT INTO `students`.`studenta`(`stuId`, `stuName`, `stuSex`, `stuHeight`, `stuAge`) VALUES (1009, '欣慰', '456', 34, '78');
INSERT INTO `students`.`studenta`(`stuId`, `stuName`, `stuSex`, `stuHeight`, `stuAge`) VALUES (1010, 'ok', '456', 34, '78');
SELECt *FROM studenta;
select * FROM student;
INSERT INTO `students`.`studenta`(`stuId`, `stuName`, `stuSex`, `stuHeight`, `stuAge`) VALUES (1011, '三体', '456', 34, '78');
INSERT INTO `students`.`studenta`(`stuId`, `stuName`, `stuSex`, `stuHeight`, `stuAge`) VALUES (10012, '学Java很快哦', '345', 34, '67')
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1007, 'hellows', '男', 24)
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1007, '胡期', '男', 35);
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (10071, '分解', '男', 35);
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (10072, '信他', '男', 35);
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (10073, 'comon', '男', 35);
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (10074, '自由', '男', 35);
DESC stu;
SELECt * FROM stu;
INSERT INTO `students`.`student`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1006, 'hellow', '男', 24)
INSERT INTO `students`.`stu`(`stuId`, `stuName`, `stuSex`, `stuAge`) VALUES (1075, '小王', '女', 23)；
DESC stu;
DESC student
select * FROM student;
UPDATe `students`.`student` SET `stuName` = 'need' WHERe `stuId` = 1007
DELETE FROM `students`.`student` WHERe `stuId` = 1006
回顾了一下mysql的基本语法。
java代码。
@1导入构架包
package jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
public class JDBCDamo1 {
public static void main(String[] args) throws Exception{
// 加载驱动类
Class.forName("com.mysql.cj.jdbc.Driver");
System.out.println("加载驱动类成功");
//地址
String url ="jdbc:mysql://127.0.0.1:3306/students";
System.out.println("mysql连接成功");
String username="root";
String password="123456";
Connection conn=DriverManager.getConnection(url,username,password);
System.out.println(conn);
System.out.println(url);
System.out.println(username);
System.out.println(password);
System.out.println(conn.getHoldability());
System.out.println(conn.getAutoCommit());
System.out.println(conn.getCatalog());
System.out.println(conn.getClientInfo(password));
System.out.println(conn.isClosed());
System.out.println(conn.isReadonly());
System.out.println(conn.isValid(conn.getHoldability()));
System.out.println(conn.toString());
System.out.println(conn.equals(username));
System.out.println(conn.prepareCall(username));
System.out.println(conn.prepareCall(url));
System.out.println(conn.prepareCall(password));
System.out.println(conn.getWarnings());
System.out.println(conn.setSavepoint());
System.out.println(conn.createStatement());
System.out.println(conn.setSavepoint());
System.out.println(conn.createBlob());
System.out.print(conn.createSQLXML());
System.out.println(conn.hashCode());
}
}
package Gradation;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Tran {
static Connection con;
static Statement sql;
static ResultSet res;
public Connection getConnection() {
return con;
}
public static void main(String[] args) throws Exception {
Class.forName("com.mysql.cj.jdbc.Driver");
System.out.println("加载驱动类成功");
//地址
String url ="jdbc:mysql://127.0.0.1:3306/student";
System.out.println("mysql连接成功");
String username="root";
String password="123456";
Connection conn=DriverManager.getConnection(url,username,password);
System.out.println(conn);
Gradation c=new Gradation();
con=c.getConnection();
try {
sql=con.createStatement();
res=sql.executeQuery("select*from tb_stu where"+"name like '胡%'");
while(res.next()) {
String id =res.getString("id");
String name=res.getString("name");
String sex=res.getString("sex");
String birthday=res.getString("birthday");
System.out.println(id);
System.out.println(name);
System.out.println(sex);
System.out.println(birthday);
}
} catch (Exception e) {
//e.printStackTrace();
}
}
}
package jdbc;
import java.sql.*;
//查询学生信息
//查询信息
public class JDBCCha {
public static void main(String[] args) throws Exception {
// 建立链接
Connection conn = DBUtil.getConnection();
//创建statement对象
Statement stmt =conn.createStatement();
//执行mysql语句
String sql="select *from student";
ResultSet rs =stmt.executeQuery(sql);
//遍历集合
while(rs.next()) {
int stuId=rs.getInt("stuId");
String stuName=rs.getString("stuName");
String stuSex=rs.getString("stuSex");
int stuAge=rs.getInt("stuAge");
System.out.println(stuId+"---------"+stuName+"-----------"+stuSex+"---------"+stuAge);
}
//关闭数据库连接
DBUtil.getClose(conn);
}
}
package jdbc;
import java.sql.*;
//查询学生信息
//删除信息
public class JDBCDelect {
public static void main(String[] args) throws Exception {
// 建立链接
Connection conn = DBUtil.getConnection();
//创建statement对象
Statement stmt =conn.createStatement();
//执行mysql语句
String sql="delect from student";
ResultSet rs =stmt.executeQuery(sql);
//遍历集合
}
}
package jdbc;
import java.sql.*;
public class JDBCShan {
//修改信息
public static void main(String[] args) throws Exception {
// 建立链接
Connection conn = DBUtil.getConnection();
//
Statement stmt =conn.createStatement();
String sql="update student set stuSex='女'";
stmt.executeLargeUpdate(sql);
DBUtil.getClose(conn);
}
}
package jdbc;
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
//增加信息
public class JDBCZeng {
public static void main(String[] args) throws Exception{
Connection conn=DBUtil.getConnection();
System.out.println(conn);
//获取 statement对象
Statement stmt =conn.createStatement();
//增加
String sql="insert into student (stuId,stuName,stuSex,stuAge) values(1003,'sanmao','女'，20)";
//4 执行语句
int count= stmt.executeUpdate(sql);
if(count>0) {
System.out.println("学生插入成功");
}else {
System.out.println("in the end");
}
//5 int the end
//conn.close();
DBUtil.getClose(conn);
// 加载驱动类
//Class.forName("com.mysql.cj.jdbc.Driver");
//System.out.println("加载驱动类成功");
//建立数据库
//String url ="jdbc:mysql://127.0.0.1:3306/students";
//System.out.println("mysql连接成功");
//String username="root";
//String password="123456";
//Connection conn=DriverManager.getConnection(url,username,password);
//System.out.println(conn);
}
}
package jdbc;
public class Student {
private int stuId;
private String stuName;
private String stuSex;
private int stuAge;
public Student() {
super();
// TODO Auto-generated constructor stub
}
public Student(int stuId, String stuName, String stuSex, int stuAge) {
super();
this.stuId = stuId;
this.stuName = stuName;
this.stuSex = stuSex;
this.stuAge = stuAge;
}
public int getStuId() {
return stuId;
}
public void setStuId(int stuId) {
this.stuId = stuId;
}
public String getStuName() {
return stuName;
}
public void setStuName(String stuName) {
this.stuName = stuName;
}
public int getStuAge() {
return stuAge;
}
public void setStuAge(int stuAge) {
this.stuAge = stuAge;
}
@Override
public String toString() {
return "Student [stuId=" + stuId + ", stuName=" + stuName + ", stuSex=" + stuSex + ", stuAge=" + stuAge + "]";
}
}
package Code;
public class CodeDemo1 {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
String str="我爱距离100km江西南字符昌学lookforyou江西区的学院";
//将字符串转成编码
byte [] by =str.getBytes("utf-8");
//将数据给用户看
String str1 =new String(by,"utf-8");
System.out.println(str1);
//网页定义utf-8
String str2="我爱距离100km温州瓯江";
//将字符串转成编码
byte [] by1 =str1.getBytes("gbk");
//将数据给用户看
String str3 =new String(by,"gbk");
System.out.println(str2);
System.out.println(str.getBytes());
System.out.println(str);
System.out.println(str2);
}
}
package readingrandwriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class CopeFile {
public static void main(String[] args) throws IOException {
//创建字节输入
FileInputStream fis= new FileInputStream("C:\Users\MZFAITHDREAM\Desktop\Javaday1_9.zip");
//创建字节输出
FileOutputStream fos =new FileOutputStream("D:\Day");
//字符输入
InputStreamReader isr=new InputStreamReader(fis,"utf-8");
//字符输出
OutputStreamWriter osr=new OutputStreamWriter(fos,"utf-8");
//创建一个数组去放入取到的数据
char[] cr=new char[1024];
int num=0;
//while
while((num=isr.read(cr))!=-1) {
//reading
osr.write( cr,0,num);
}
isr.close();
osr.close();
}
}
package readingrandwriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class CopeFile2 {
public static void main(String[] args) throws IOException {
//创建字节输入
//FileInputStream fis= new FileInputStream("C:\Users\MZFAITHDREAM\Desktop\Javaday1_9.zip");
//创建字节输出
//FileOutputStream fos =new FileOutputStream("D:\Day");
//字符输入
//InputStreamReader isr=new InputStreamReader(fis,"utf-8");
//字符输出
//OutputStreamWriter osr=new OutputStreamWriter(fos,"utf-8");
FileReader fr=new FileReader("C:\Users\MZFAITHDREAM\Desktop\青年大学习第10期.xlsx");
FileWriter fw=new FileWriter("D:\dayop1");
//创建一个数组去放入取到的数据
char[] cr=new char[1024];
int num=0;
//while
while((num=fr.read(cr))!=-1) {
//reading
fw.write( cr,0,num);
}
fr.close();
fw.close();
}
}
package repeat;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Copy1 {
public static void main(String[] args) throws IOException{
// TODO Auto-generated method stub
FileInputStream fis= new FileInputStream("C:\Users\MZFAITHDREAM\Desktop\1.jpg");
FileOutputStream fos =new FileOutputStream("D:\胡滨.jpg" ,true);
byte[] by =new byte[1024];
//int read(byte[]) by)
int num=0;
while((num=fis.read(by))!=-1) {
//reading
fos.write(by, 0, num);
}
//关闭流
fis.close();
fos.close();
}
}
package repeat;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Copy2 {
public static void main(String[] args) throws IOException{
// TODO Auto-generated method stub
FileInputStream fis= new FileInputStream("C:\Users\MZFAITHDREAM\Desktop\1.png");
FileOutputStream fos =new FileOutputStream("D:\hu.png" ,true);
byte[] by =new byte[1024];
//int read(byte[]) by)
int num=0;
while((num=fis.read(by))!=-1) {
//reading
fos.write(by, 0, num);
}
//关闭流
fis.close();
fos.close();
}
}
Exception in thread "main" java.io.FileNotFoundException: C:UsersMZFAITHDREAMDesktop1.jpg (系统找不到指定的文件。)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.(FileInputStream.java:138)
at java.io.FileInputStream.(FileInputStream.java:93)
at repeat.Copy1.main(Copy1.java:13)
