[摘要]DESC】 【LIMIT [偏移行,]记录行数】 ... DESC】
【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.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： Java连接MySQL数据库及简单操作代码 数据库基础知识 以上就是使用JAVA进行数据库部分知识的操作代码的详细内容，更多请关注php中文网其它相关文章！
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