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Background: during this period, a colleague needs to log in to my account frequently, and to verify the mobile phone verification code, I need to manually forward the verification code to him every time. I find it very troublesome, so I want to see if there is any way to free my hands, and then I find that AppleScript is such a very useful thi ...

In a real project, Mycat services also need to consider high availability. If the server Mycat is on is down, or if the Mycat service fails, it needs a standby machine to provide services and the Mycat cluster needs to be considered.Highly available options:We can use HAProxy+Keepalived with two Mycats to build Mycat clusters for high availabi ...

Article Directory 1. Description of put, post, delete, get methods 2. Data Models and Core Concepts 3. Basic operation of index 1. Create an index 2. View all current indexes 3. Modify (update) the document 4. Delete 5. Add data 6. Bulk operation data bulk 8. Bulk Read Documents 9. Search for data ...

catalog 1. Function introduction and display (multi figure warning) 2. Code design 1 database 2 login interface and verification 3 main interface 4 change of information 5 information display Tip: this semester, Java class is going to do a project of employee management system. When we first hea ...

In the development process, it is inevitable to create entity classes. Tables with fewer fields can be written manually. However, if more fields are created manually, it is a waste of time. If a table has more than 100 fields, handwriting is not realistic. At this time, we will use some tools, such as dynamic soft code generator, code generator ...

1. Preface One to many paging of MySQL data is a very common requirement. For example, we need to query the product and the image information of the product. But many people will encounter the mistake of pagination here and get incorrect results. Let's analyze and solve this problem today. 2. Problem analysis First, we create a simple product ...

Compound query The query of mysql table mentioned before is to query a table, but it is not enough in the actual development. select * from where (sal>500 or job='MANAGER')and eame like 'J%' Sort by department number in ascending order and employee's salary in descending order select * from EMP ro ...

Subquery with EXISTS predicate EXISTS predicate Existential quantifier_ Subqueries with EXISTS predicates do not return any data and only produce a logical true value or a logical false value. The outer WHERE clause returns true values if the inner query result is not empty The outer WHERE clause return ...

I. mybatis Foundation 1. Analysis of Starter Case Design Mode public static void main(String[] args) throws Exception{ //Read Configuration File InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml"); //Create SqlSessionFactory Factory /* Creating factory mybatis uses build ...

Sometimes we need to save a lot of data, which is time-sensitive, such as some logs. After a period of time, the existence of these data is not significant, and in addition to taking up a lot of hard disk space, it may make data queries slow.This data needs to be cleaned up regularly.We can cope with ...