sql复制代码--注意大小写敏感，要用小写
chis=# select oid,datname from pg_database where datname='syd';
  oid  | datname
-------+---------
 41351 | syd
(1 row)

chis=# select oid,datname from pg_database where datname='SYD';
 oid | datname
-----+---------
(0 rows)

sql复制代码--方法一：大小写敏感，要用小写
chis=# select oid,rolname from pg_authid where rolname='syd';
  oid  | rolname
-------+---------
 66934 | syd
(1 row)

chis=# select oid,rolname from pg_authid where rolname='SYD';
 oid | rolname
-----+---------
(0 rows)
--方法二：大小写不敏感，用大小写均可
chis=# select 'syd'::regrole::oid;
  oid
-------
 66934
(1 row)

chis=# select 'SYD'::regrole::oid;
  oid
-------
 66934
(1 row)

sql复制代码--方法一：大小写敏感，要用小写
chis=# select oid,nspname from pg_namespace where nspname='comm';
  oid  | nspname
-------+---------
 16398 | comm
(1 row)

chis=# select oid,nspname from pg_namespace where nspname='COMM';
 oid | nspname
-----+---------
(0 rows)

--方法二：大小写不敏感，用大小写均可
chis=# select 'comm'::regnamespace::oid;
  oid
-------
 16398
(1 row)

chis=# select 'COMM'::regnamespace::oid;
  oid
-------
 16398
(1 row)

sql复制代码--方法一：大小写敏感，要用小写
---查询表的 oid
chis=# select oid,relname from pg_class where relname='account';
  oid  | relname
-------+---------
 66640 | account
(1 row)

chis=# select oid,relname from pg_class where relname='ACCOUNT';
 oid | relname
-----+---------
(0 rows)
--查询索引的 oid
chis=# select oid,relname from pg_class where relname='pk_account_id';
  oid  |    relname
-------+---------------
 66646 | pk_account_id
(1 row)

chis=# select oid,relname from pg_class where relname='PK_ACCOUNT_ID';
 oid | relname
-----+---------
(0 rows)
--方法二：大小写不敏感，用大小写均可（注意需要指定schema名，不然表在当前schema不可见时，会报错）
---查询表的 oid
chis=# select 'account'::regclass::oid;
ERROR:  relation "account" does not exist
LINE 1: select 'account'::regclass::oid;
               ^
chis=# select 'comm.account'::regclass::oid;
  oid
-------
 66640
(1 row)

chis=# select 'COMM.ACCOUNT'::regclass::oid;
  oid
-------
 66640
(1 row)
---查询索引的 oid
chis=# select 'pk_account_id'::regclass::oid;
ERROR:  relation "pk_account_id" does not exist
LINE 1: select 'pk_account_id'::regclass::oid;
                ^
chis=# select 'comm.pk_account_id'::regclass::oid;
  oid
-------
 66646
(1 row)

chis=# select 'COMM.PK_ACCOUNT_ID'::regclass::oid;
  oid
-------
 66646
(1 row)

sql复制代码--方法一：大小写敏感，要用小写
chis=# select oid,proname from pg_proc where proname='out_tally_pepole_count';
  oid  |        proname
-------+------------------------
 16464 | out_tally_pepole_count
(1 row)

chis=# select oid,proname from pg_proc where proname='OUT_TALLY_PEPOLE_COUNT';
 oid | proname
-----+---------
(0 rows)
--方法二：大小写不敏感，用大小写均可（注意需要指定schema名，不然表在当前schema不可见时，会报错）
chis=# select 'out_tally_pepole_count'::regproc::oid;
ERROR:  function "out_tally_pepole_count" does not exist
LINE 1: select 'out_tally_pepole_count'::regproc::oid;
               ^
chis=# select 'finance.out_tally_pepole_count'::regproc::oid;
  oid
-------
 16464
(1 row)

chis=# select 'FINANCE.OUT_TALLY_PEPOLE_COUNT'::regproc::oid;
  oid
-------
 16464
(1 row)

python复制代码# 指定缩放后图像尺寸
resized_image = cv2.resize(image, (width * 2, height * 2), interpolation=cv2.INTER_LINEAR)

python复制代码# 使用缩放因子
dst_image = cv2.resize(image, None, fx=0.5, fy=0.5, interpolation=cv2.INTER_AREA)

python复制代码def show_with_matplotlib(color_img, title, pos):
    # Convert BGR image to RGB
    img_RGB = color_img[:,:,::-1]
    ax = plt.subplot(1, 3, pos)
    plt.imshow(img_RGB)
    plt.title(title,fontsize=8)
    # plt.axis('off')
show_with_matplotlib(image, 'Original image', 1)
show_with_matplotlib(dst_image, 'Resized image', 2)
show_with_matplotlib(dst_image_2, 'Resized image 2', 3)
plt.show()

python复制代码M = np.float32([[1, 0, x], [0, 1, y]])

python复制代码dst_image = cv2.warpAffine(image, M, (width, height))

python复制代码height, width = image.shape[:2]
M = np.float32([[1, 0, 200], [0, 1, 30]])
dst_image_1 = cv2.warpAffine(image, M, (width, height))

python复制代码M = np.float32([[1, 0, -200], [0, 1, -30]])
dst_image_2 = cv2.warpAffine(image, M, (width, height))

python复制代码height, width = image.shape[:2]
M = cv2.getRotationMatrix2D((width / 2.0, height / 2.0), 180, 1)
dst_image = cv2.warpAffine(image, M, (width, height))

python复制代码M = cv2.getRotationMatrix2D((width/1.5, height/1.5), 30, 1)
dst_image_2 = cv2.warpAffine(image, M, (width, height))

python复制代码pts_1 = np.float32([[135, 45], [385, 45], [135, 230]])
pts_2 = np.float32([[135, 45], [385, 45], [150, 230]])
M = cv2.getAffineTransform(pts_1, pts_2)
dst_image = cv2.warpAffine(image_points, M, (width, height))

python复制代码pts_1 = np.float32([[450, 65], [517, 65], [431, 164], [552, 164]])
pts_2 = np.float32([[0, 0], [300, 0], [0, 300], [300, 300]])
M = cv2.getPerspectiveTransform(pts_1, pts_2)
dst_image = cv2.warpPerspective(image, M, (300, 300)

python复制代码dst_image = image[80:200, 230:330]

xml复制代码<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-aop -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
    <version>2.5.2</version>
</dependency>

less复制代码/**
* 自定义 log注解
*
* @author Smile
*/
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SysLog {
  /**
   * 记录业务名称
   *
   * @return 业务名称
   */
  String value() default "";
}

java复制代码@Resource
private SysLogService logService;
private SysLogPO sysLogPO = new SysLogPO();

/**
 * 这个是切点的意思，从什么地方切入： 可以是具体的类或者注解 ，也可以是模糊的类路径 * *..*Api.*(..)
 */
@Pointcut("@annotation(com.smile.ssm.aop.annotation.SysLog)")
public void annotationPointcut() {
}

/**
 * 前置通知, 在方法执行之前执行
 *
 * @param joinPoint xx
 */
@Before("annotationPointcut()")
public void beforePointcut(JoinPoint joinPoint) {
    System.out.println("beforePointcut");

}

/**
 * 环绕通知, 围绕着方法执行
 *
 * @param point
 * @return
 * @throws Throwable
 */
@Around("annotationPointcut()")
public Object doAround(ProceedingJoinPoint point) throws Throwable {
    System.out.println("doAround");
    RequestAttributes ra = RequestContextHolder.getRequestAttributes();
    ServletRequestAttributes sra = (ServletRequestAttributes) ra;
    HttpServletRequest request = sra.getRequest();
    //这个是获取调用的方法类型:get post ...
    String method1 = request.getMethod();
    String url = request.getRequestURL().toString();
    sysLogPO.setMethod(url);
    sysLogPO.setDeleted(false);
    sysLogPO.setCreateTime(LocalDateTime.now());
    //获得执行方法的类名
    String targetName = point.getTarget().getClass().getName();
    //获得执行方法的方法名
    String methodName = point.getSignature().getName();
    //获取切点方法的所有参数类型
    Object[] arguments = point.getArgs();
    try {
        Class targetClass = Class.forName(targetName);
        //获取公共方法，不包括类私有的
        Method[] methods = targetClass.getMethods();
        String value = "";
        for (Method method : methods) {
            if (method.getName().equals(methodName)) {
                //对比方法中参数的个数
                Class[] clazzs = method.getParameterTypes();
                if (clazzs.length == arguments.length) {
                    value = method.getAnnotation(SysLog.class).value();
                    break;
                }
            }
        }
        sysLogPO.setBusinessName(value);
    } catch (Exception e) {
        e.printStackTrace();
    }

    logService.save(sysLogPO);
    log.info("===请求开始, 各个参数, url: " + url + ", method: " + method1 + ", uri:" + request.getRequestURI() + ", params:" + request.getQueryString());
    if (arguments != null) {
        for (Object argument : arguments) {
            log.info("===接口入参:" + JSON.toJSONString(argument));
        }
    }
    return point.proceed();

}

/**
 * 返回通知, 在方法返回结果之后执行
 *
 * @param joinPoint xx
 */
@AfterReturning("annotationPointcut()")
public void doAfterReturning(JoinPoint joinPoint) {
    System.out.println("doAfterReturning");
}

/**
 * 异常通知, 在方法抛出异常之后
 */
@AfterThrowing("annotationPointcut()")
public void doAfterThrowing(JoinPoint joinPoint) {
    System.out.println("doAfterThrowing");
}

/**
 * 后置通知, 在方法执行之后执行
 */
@After("annotationPointcut()")
public void doAfter(JoinPoint joinPoint) {
    System.out.println("doAfter");
}

less复制代码@Pointcut

1）execution(* *(..))  
//表示匹配所有方法  
2）execution(public * com.smile.ssm.service.*Api*(..))  
//表示匹配com.smile.ssm.UserService中所有的公有方法  
3）execution(* com.smile.ssm..*.*(..))  
//表示匹配com.savage.server包及其子包下的所有方法

java复制代码/**
 * 搭配切点使用前置通知, 在方法执行之前执行
 *
 * @param joinPoint xx
 */
@Before("annotationPointcut()")

java复制代码/**
 * 环绕通知, 围绕着方法执行
 *
 * @param point
 * @return
 * @throws Throwable
 */
@Around("annotationPointcut()")

markdown复制代码/**
 * 返回通知, 在方法返回结果之后执行
 *
 * @param joinPoint xx
 */

arduino复制代码/**
 * 异常通知, 在方法抛出异常之后
 */

arduino复制代码/**
 * 后置通知, 在方法执行之后执行
 */

python复制代码import matplotlib.pyplot as plt 
plt.streamplot(x,y,u,v)

python复制代码import matplotlib.pyplot as plt

python复制代码x = np.arange(1,10)
y = np.arange(1,10)

u,v = np.meshgrid(np.sin(x),np.sin(y))

python复制代码plt.streamplot(x,y,u,v,density=[0.5,1])

python复制代码plt.show()

python复制代码plt.streamplot(x,y,u,v,density=[0.5,1],color=u,cmap="Accent_r",linewidth=3)

python复制代码y,x= np.mgrid[-3:3:100j, -3:3:100j]
u = -1-x**2+y
v = 1+x-y**2

seed_points = np.array([[-2, -1, 0, 1, 2, -1], [-2, -1, 0, 1, 2, 2]])
plt.streamplot(x,y,u,v,density=0.6,color=u,cmap="autumn",linewidth=1,start_points=seed_points.T)
plt.plot(seed_points[0],seed_points[1],"^",color="b")

plt.show()

java复制代码public class Student {
    // 姓名
    private String name;
    // 年龄
    private int age;
    // 性别 0-女 1-男
    private int sex;

    public Student() {
    }
    public Student(String name, int age, int sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }
    public void eat(){
        System.out.println("学生要吃饭");
    }
    public void study(){
        System.out.println("学生要学习");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }
}

java复制代码public class Teacher {
    // 姓名
    private String name;
    // 年龄
    private int age;
    // 性别 0-女 1-男
    private int sex;

    public Teacher() {
    }
    public Teacher(String name, int age, int sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }
    public void eat(){
        System.out.println("老师要吃饭");
    }
    public void teach(){
        System.out.println("老师要讲课");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }
}

java复制代码class 类名 extends 父类名{
    方法+属性
}

java复制代码public class Person {
    // 姓名
    private String name;
    // 年龄
    private int age;
    // 性别 0-女 1-男
    private int sex;

    public Person() {
    }

    public Person(String name, int age, int sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public void eat(){
        System.out.println("人要吃饭");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }
}

java复制代码public class Student extends Person{
    private void study(){
        System.out.println("学生要学习");
    }
}

scala复制代码public class Teacher extends Person {
    private void teach(){
        System.out.println("老师要讲课");
    }
}

java复制代码// 继承测试类
public class ExtendTest {
    public static void main(String[] args) {
        Student student = new Student();
        student.setName("一颗雷布斯");
        student.setAge(19);
        Teacher teacher = new Teacher();
        teacher.setName("张三丰");
        teacher.setAge(30);

        System.out.println("学生姓名："+student.getName());
        System.out.println("学生年龄："+student.getAge());
        student.eat();
        System.out.println("---------------------------");
        System.out.println("老师姓名："+teacher.getName());
        System.out.println("老师年龄："+teacher.getAge());
        teacher.eat();
    }
}

java复制代码public class Student extends Person{
    public void eat(){
        System.out.println("学生要想学习好，必须好好吃饭！！");
    }
}

java复制代码// 继承测试类
public class ExtendTest {
    public static void main(String[] args) {
        Student student = new Student();
        student.eat();
    }
}

java复制代码public class Student extends Person{

    public void eat(){
        System.out.println("学生要想学习好，必须好好吃饭！！");
    }

    public void eat(String name){
        System.out.println(name+"在吃饭");
    }

    public void eat(int age,String name){
        if(age > 18){
            System.out.println(name+"喜欢吃牛肉");
        }else {
            System.out.println(name+"喜欢吃猪肉");
        }
    }
}

java复制代码// 继承测试类
public class ExtendTest {
    public static void main(String[] args) {
        Student student = new Student();
        student.eat();
        student.eat("波吉");
        student.eat(14,"卡克");
    }
}

java复制代码public class A {
    public A() {
        System.out.println("父类构造方法被调用了");
    }
}

java复制代码public class B extends A{
    public B() {
        System.out.println("子类构造方法被调用了");
    }
}

java复制代码public class ExtendTest {
    public static void main(String[] args) {
        B b = new B();
    }
}

java复制代码public class A {
    public String name = "哈哈哈";
    public void eat(){
      System.out.println("父亲要吃饭");
    }
}

java复制代码public class B extends A{
    private String name = "哦哦哦";
    public void print(){
        System.out.println("父亲名字："+super.name);
        System.out.println("儿子名字："+this.name);
    }
    public void eat() {
        System.out.println("儿子要吃饭");
        super.eat();
    }
}

java复制代码public class ExtendTest {
    public static void main(String[] args) {
        B b = new B();
        b.print();
        b.eat();
    }
}

java复制代码public class ExtendTest {
    public static void main(String[] args) {
        Student student = new Student();
        student.setName("波吉");
        student.setAge(14);
        System.out.println(student.toString());
        System.out.println(student.getName().equals("卡克"));
    }
}

java复制代码public class Student extends Person{
    @Override
    public String toString() {
       return "姓名："+this.getName()+",年龄："+this.getAge();
    }
}

java复制代码public class ExtendTest {
    public static void main(String[] args) {
        Student student = new Student();
        student.setName("波吉");
        student.setAge(14);
        System.out.println(student.toString());
    }
}

java复制代码public static void main(String[] args) {
   String name1= "波吉";
   String name2= "波吉";
   System.out.println(name1.equals(name2));
}

less复制代码CREATE TABLE `db_mysql_escape`.`t_suitable_data_type` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `name` varchar(32) NOT NULL,
    `gender` ENUM('male', 'female') NOT NULL,
    `grade` ENUM('0', '1', '2') NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

ini复制代码desc t_suitable_data_type;

go复制代码INSERT INTO `db_mysql_escape`.`t_suitable_data_type`(`id`, `name`, `gender`, `grade`) VALUES (1, 'abc', 'male', '1');
​

go复制代码INSERT INTO `db_mysql_escape`.`t_suitable_data_type`(`id`, `name`, `gender`, `grade`) VALUES (2, 'abc', 'male', '9');

csharp复制代码select name, gender + 0, grade from t_suitable_data_type;

python复制代码{'code': 400, 'message': 'fail', 'data': None}

python复制代码import threading
from threading import Lock, Thread
import time
import os
import requests
import random


class MyThread(threading.Thread):
    def __init__(self, name):
        super(MyThread, self).__init__()
        self.name = name

    def run(self):
        global urls
        lock.acquire()
        one_url = urls.pop()
        print("正在爬取：", one_url)
        lock.release()
        print("任意线程等待随机时间")
        time.sleep(random.randint(1,3))
        res = requests.get(one_url, headers=self.get_headers(), timeout=5)

        if  res.json()["code"] != 400:
            data = res.json()["data"]["list"]
            for user in data:
                name = user['username']
                nickname = self.remove_character(user['nickname'])
                userAvatar = user['userAvatar']
                blogUrl = user['blogUrl']
                blogExpert = user['blogExpert']
                briefIntroduction = self.remove_character(
                    user['briefIntroduction'])

	            with open('./qing_gee_data.csv', 'a+', encoding='utf-8') as f:
	                print(f'{name},{nickname},{userAvatar},{blogUrl},{blogExpert},{briefIntroduction}')
	                f.write(f"{name},{nickname},{userAvatar},{blogUrl},{blogExpert},{briefIntroduction}\n")
        else:
            print(res.json())
            print("异常数据", one_url)
            with open('./error.txt', 'a+', encoding='utf-8') as f:
                f.write(one_url+"\n")
    # 去除特殊字符

    def remove_character(self, origin_str):
        if origin_str is None:
            return
        origin_str = origin_str.replace('\n', '')
        origin_str = origin_str.replace(',', '，')
        return origin_str
	# 获取随机UA请求头
    def get_headers(self):
        uas = [
            "Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)"
        ]
        ua = random.choice(uas)
        # 特别注意下述 cookie 部分，需要手动从开发者工具中进行复制，否则抓取到的数据，缺少nikename 与个人简介部分
        headers = {
            "user-agent": ua,
            'cookie': 'UserName=你的ID; UserInfo=你的UserInfo; UserToken=你的UserToken;',
            "referer": "https://blog.csdn.net/qing_gee?type=sub&subType=fans"
        }
        return headers


if __name__ == '__main__':
    lock = Lock()
    url_format = 'https://blog.csdn.net/community/home-api/v1/get-fans-list?page={}&size=20&noMore=false&blogUsername=qing_gee'
    urls = [url_format.format(i) for i in range(1, 13300)]
    l = []
    while len(urls) > 0:
        print(len(urls))
        for i in range(5):
            p = MyThread("t"+str(i))
            l.append(p)
            p.start()
        for p in l:
            p.join()

python复制代码import threading
import time

def run(n):
    print('task', n)
    time.sleep(3)

if __name__ == '__main__':
    t1 = threading.Thread(target=run, args=('t1',))
    t2 = threading.Thread(target=run, args=('t2',))
    t1.start()
    t2.start()

python复制代码import threading
from threading import Lock,Thread
import time,os

def work():
    global urls
    lock.acquire()
    # 获取一个 url
    one_url = urls.pop()
    lock.release()

    print("得到的 URL 为",one_url)


if __name__ == '__main__':
    lock = Lock()
    url_format = 'https://blog.csdn.net/community/home-api/v1/get-fans-list?page={}&size=20&noMore=false&blogUsername=qing_gee'
    # 拼接URL，全局共享变量
    urls = [url_format.format(i) for i in range(1, 13300)]
    l = []
    # 开启线程数量
    for i in range(3):
        p = Thread(target=work)
        l.append(p)
        p.start()
    for p in l:
        p.join()