本週首先暫時結束了java高階知識，進入了資料庫的學習：
java進階部分：
1.多執行緒：執行緒執行階段（多個執行緒操作共享變數） ;
鎖機制，關鍵字有synchronize( （悲觀）死鎖，,wait，notify,notifyAll;
2.網路程式設計： UDP資料廣播（資料傳送者只需傳送一個拷貝，交換器 與 Json資料格式，語法規則：JSON物件{"屬性名稱":"屬性值"}
JSON外掛程式：- Json-lib
- Gson
- Jackson
- FastJSON - alibaba
;
資料庫部分：（採用mysql5.5資料庫，以及navicat圖形工具對其操作）
系統指令（以管理者身分運作）
： #啟動服務
net start mysql
#停止服務
# # #排列
mysql -uroot -p密碼
#
#退出mysql指令 #修改密碼
備份資料庫執行個體 mysqldump -uroot -proot mydb > d:/mydb.sql
#備份表 mysqldump -uroot -proot mydb tbuser > d:/tbuser.sql
： --顯示資料庫執行個體
show databases;
--建立資料庫執行個體
create database mydb;
# user mydb;
語句
(not null unique)
DDL（資料庫定義語言：用來建立資料庫、資料庫物件和定義其列）：create、desc（檢視表格結構） 、alter、drop
中註解時（資料庫操縱語言中：增約 修正值 DCL（資料庫控制語言：控制權限）revork，grant;
2. 外鍵約束
3. 不為空限制
5. 檢查約束(mysql暫不支援)
# 6.資料類型、運算子
FROM 目標表
## 【WHERE 查詢條件】
【GROUP BY 欄位名稱】
詢問條件】
【LIMIT [偏移行,]记录行数】
单表查询：模糊查询（“%”，“_”），聚合函数
多表查询：等值连接，外连接
mysql函数的使用。
import java.io.Serializable;
/**
* 工作详情类
* @author NIUXUYUAN
*/
public class Jobs implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private String id; //id
private String experience; //工作经验
private String city; //工作地点
private String industry; //行业
private String detail; //工作详情
private String company; //公司
private String jobname; //职位
public Jobs(String id, String experience, String city, String industry, String detail, String company,
String jobname) {
super();
this.id = id;
this.experience = experience;
this.city = city;
this.industry = industry;
this.detail = detail;
this.company = company;
this.jobname = jobname;
}
@Override
public String toString() {
return "Jobs [id=" + id + ", experience=" + experience + ", city=" + city + ", industry=" + industry
+ ", detail=" + detail + ", company=" + company + ", jobname=" + jobname + "]";
}
public String toString(int i) {
return experience+city+industry+detail+company+jobname;
}
public Jobs() {
// TODO Auto-generated constructor stub
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getExperience() {
return experience;
}
public void setExperience(String experience) {
this.experience = experience;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getIndustry() {
return industry;
}
public void setIndustry(String industry) {
this.industry = industry;
}
public String getDetail() {
return detail;
}
public void setDetail(String detail) {
this.detail = detail;
}
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
public String getJobname() {
return jobname;
}
public void setJobname(String jobname) {
this.jobname = jobname;
}
}import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;
public class AddJobs {
static List<Jobs> list = new ArrayList<>();
File file = new File("jobs");
/**
* 输入数据
* @throws IOException
*/
public void input() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("以id/experience/education/city/industry/detail/company/jobname格式填入：");
String msg = "";
while(!(msg = br.readLine()).equalsIgnoreCase("quit")) {
add(msg);
}
br.close();
}
/**
* 将数据变为Jobs对象存入list集合
* @param msg
*/
private void add(String msg) {
String[] s = msg.split("/");
Jobs job = new Jobs(s[0], s[1], s[2], s[3], s[4], s[5], s[6]);
list.add(job);
}
private void checkFile() throws FileNotFoundException, IOException, ClassNotFoundException {
if(file.length()>0) {
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file));
List<Jobs> temp = (List<Jobs>)ois.readObject();
if(temp!=null) {
list.clear();
for(Jobs t:temp) {
list.add(t);
}
}
ois.close();
}
}
public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
AddJobs aj = new AddJobs();
if(!aj.file.exists()) {
aj.file.createNewFile();
}
aj.checkFile();
aj.input();
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(aj.file));
oos.writeObject(list);
oos.close();
}
}import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.util.ArrayList;
import java.util.List;
public class Query {
static List<Jobs> list = new ArrayList<>();
File file = new File("jobs");
/**
* 查看file文件，将数据导入list集合
* @throws FileNotFoundException
* @throws IOException
* @throws ClassNotFoundException
*/
private void checkFile() throws FileNotFoundException, IOException, ClassNotFoundException {
if(file.length()>0) {
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file));
List<Jobs> temp = (List<Jobs>)ois.readObject();
if(temp!=null) {
list.clear();
for(Jobs t:temp) {
list.add(t);
}
}
ois.close();
}
}
public void check() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("请输入experience/education/city/industry/detail/company/jobname的某些信息");
String msg = br.readLine();
String[] s = msg.split("/");
String regex = "";
for (String str : s) {
regex += "[\\s\\S]*" + str + "[\\s\\S]*";
}
List<Jobs> temp = new ArrayList<>();
for (Jobs j : list) {
msg = j.toString(1);
if(msg.matches(regex)) {
temp.add(j);
}
}
System.out.println("结果");
for (Jobs jobs : temp) {
System.out.println(jobs);
}
}
public static void main(String[] args) throws FileNotFoundException, ClassNotFoundException, IOException {
Query q = new Query();
q.checkFile();
q.check();
}
}相关文章：
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