Question 1: Use the express framework of Node.js and JQuery to complete the following requirements: 1. Design a login page. It is required to enter the user name, password and login button on the login page. 2. When clicking the login button, use JQuery's AJAX to post the contents of the form. 3. Use node.js and express to b ...
Posted by KissMyBrain on Sat, 20 Nov 2021 11:51:09 -0800
Recently, there was a query using the general mapper of mybatis. Since I contacted the general mapper, I simply summarized the records so as to help later people.
1, First, put the interface code Mapper.class of mybatis general mapper:
Posted by einamiga on Sat, 20 Nov 2021 04:40:56 -0800
Data management of MySQL
1.DML language (very important)
The meaning of database: data storage and data management
DML: Data Manipulation Language
2. Foreign keys
Method 1: add constraints to the primary key when creating a table (more complex)
CREATE TABLE `grade`(
`gradeid` INT(10) NOT NULL AUTO_INCREMENT CO ...
Posted by kharbat on Fri, 19 Nov 2021 23:01:57 -0800
0. Project construction
As usual, let's build a new project first configuration The project is a little messy. The name of the project is what we call it mybatis-03-mapper Well, the imported dependencies are the same as before, and then simplify the previous code.
The copied project structure and documents shall be ...
Posted by s1yman on Fri, 19 Nov 2021 16:53:02 -0800
Introduction to character sets and comparison rules
Character set introduction
We know that only binary data can be stored in the computer, so how to store strings? Of course, it is necessary to establish the mapping relationship between characters and binary data. To establish this relationship, at least two things should be clear:
What ch ...
Posted by adnanhb on Fri, 19 Nov 2021 05:46:22 -0800
1. Problem description
I saw a blank question from my colleagues in the group two days ago. The general phenomenon is as follows:
mysql> select @@version;
| @@version |
| 8.0.25 |
1 row in set (0.00 sec)
mysql> create table t1(
-> c1 int,
-> c2 varchar(4) check(c2<>'') # ...
Posted by aaronrb on Thu, 18 Nov 2021 21:55:04 -0800
1, Overview of backup and recovery
1.1 backup function
Disaster recovery: hardware failure, software failure, natural disaster, hacker attack, misoperation test and other data loss scenarios
1.2 types of backup
Full backup: backs up the entire databasePartial backup: backs up a subset of the database, such as a partial library or tableI ...
Posted by Jeyush on Thu, 18 Nov 2021 13:22:47 -0800
Pay attention to the versions of different software you use. It's best to match them. If they don't match, I haven't tried, and there may be errors
The memory of a single machine should be more than 2G, and 3G is the best. It should be for all the memory consumption compared on one machine. The memory service can not be started if it ...
Posted by env3rt on Thu, 18 Nov 2021 05:12:26 -0800
1 sliding window
priority_queue is often used
0480 sliding window median
2 problem solving ideas
1 use a multiset to maintain the current window,
1.1 do not use priority_ The element cannot be deleted because of the queue1.2 the reason why map/set is not used cannot contai ...
Posted by teongkia on Wed, 17 Nov 2021 23:36:42 -0800
Absrtact: using SQL as the entry of data query and analysis is an idea of data full stack.
This article is shared from Huawei cloud community< How to use SQL to analyze data? >, author: zuozewei.
We process user data in real time through OLTP (online transaction processing) system, and we also need to analyze them in OLAP ( ...
Posted by neutra on Wed, 17 Nov 2021 23:07:19 -0800