This paper connects MyBatis basic learning knowledge point 1 and continues to discuss the following two issues
1. What is Dao configuration file mainly used for? How to configure?
2. How to test program running with test method? What does each stat ...
1, Create library and table classes
create database a;//Create database
create table name(
Field name char(10),
Field name 2 char(10)
drop Command is also the method of use
2, Modify table data
alter table student drop column Field name;
alter table student add column Field na ...
Added by aeafisme23 on Fri, 04 Feb 2022 14:23:43 +0200
Date: February 4
1. Higher order function
What is a Function: a Function is a data type [Function] Function that can be defined by an expression
Higher order function: since a function is of a type and can be used as a parameter or return value of another function, the function is called a higher-order function (simply a function calling fu ...
Added by jwer78 on Fri, 04 Feb 2022 06:59:02 +0200
Nanshen blog: https://www.wlhhlc.top/
y4 blog: https://y4tacker.blog.csdn.net/
feng blog: https://ego00.blog.csdn.net/
Let's just start sql injection now.
Just after entering, we can see that there are three columns: id, username and password
The statement is
$sql = "select username,passwor ...
Added by devarticles on Thu, 03 Feb 2022 10:31:56 +0200
MySQL database basic topic is coming!
Hee-hee, this term I learned the fundamentals of MySQL database, and then I have sorted out some simple questions that are useful for MySQL database, I hope you can help!
Say nothing, go dry!
Table structure management
1. Creation and deletion of MySQL database 2. Create, modify, delete ...
Added by TLawrence on Tue, 01 Feb 2022 15:38:53 +0200
Operation of summary table
Summarize according to Master Kang's video tutorial, which is convenient for individuals to review, query and use
Create and manage tables
CREATE DATABASE IF NOT EXISTS XXXXXX;
CREATE DATABASE XXXXXX CHARACTER SET 'UTF8';
#modify the database
ALTER DATABASE xxxxxx CHARA ...
Added by Pavlos1316 on Tue, 01 Feb 2022 04:25:23 +0200
1. Index index
Indexing is a fast, ordered data structure that helps databases efficiently retrieve data. In addition to data, the database system maintains data structures (additional storage space) that satisfy specific lookup algorithms, which point to the data in some way so that efficient lookup algorithms can be implemente ...
Introduction: in the morning, I received a text message with the content of "Dear Hello, XXX". At that time, I smiled.
It's a joke that programmers can Get. It shows that the program doesn't Get my name correctly from the database, and then formats the null value as null. To get back to business, the reason for this situation i ...
Added by cip6791 on Mon, 31 Jan 2022 09:35:08 +0200
The order information table records the information of Brazilian passengers using taxi software, including order call, response, cancellation and completion time.
-order_id: order ID，Call order ID
-passenger_id:passenger ID，Passenger identification number
-call_time:Call time, the time point when the passenger sends the request for car use f ...
Set operation of table, addition and subtraction
A set represents "the sum of all kinds of things" in the field of mathematics and a set of records in the field of database Specifically, the execution results of tables, views and queries are a collection of records, in which the elements are each row in the table or query results. In ...