[toc]1. New features1.2 add MGR role columnIn MySQL 5.7, query performance_schema.replication_group_members, no member_ The role column is not easy to quickly check which node is the Primary Node.In GreatSQL, this column is added to make it easier to view node roles and more friendly to some middleware support.mysql> select * from performanc ...
Posted by willfitch on Thu, 07 Apr 2022 12:06:10 +0300
The original content of GreatSQL community cannot be used without authorization. Please contact Xiaobian and indicate the source for reprint.The main index types of MySQL are as follows:1. Primary key index2. Unique index3. General index4. Spatial index5. Full text indexSuppose there is a table belowCREATE TABLE `t1` (
`id` bigint unsigned NO ...
Posted by darksystem on Wed, 06 Apr 2022 05:44:02 +0300
Load driverLink the database to get the database object DriverManagerGets the Statement object that executes SQLGet the returned result setRelease connection
key word: Connection database link object Statement the object that executes the SQL statement ResultSet returned result set object
Load driver DriverManager
Posted by lordshoa on Wed, 06 Apr 2022 02:21:53 +0300
SQL7 average time of browsing articles per day in November 2021
DROP TABLE IF EXISTS tb_user_log;
CREATE TABLE tb_user_log (
id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'Self increasing ID',
uid INT NOT NULL COMMENT 'user ID',
artical_id INT NOT NULL COMMENT 'video ID',
in_time datetime COMMENT 'Entry time',
out_time dat ...
Mysql recursive query
For tree structure data in the database, such as department table, sometimes we need to know all subordinate parts of a department or all superior departments of a part. At this time, we need to use recursive query of data!
If oracle implements recursive query, we can use the START WITH... CONNECT BY function syntax ...
Posted by jdbfitz on Sun, 03 Apr 2022 13:58:39 +0300
1. First knowledge database
1.1. What is a database
DataBase: DB (DataBase)
Concept: data warehouse, software, installed on the operating system
Function: store data and manage data
1.2. Database classification
Relational database: SQL (Structured Query Language)
MySQL,Oracle,Sql Server,DB2,SQLliteData is stored through the relation ...
Posted by jeva39 on Sun, 03 Apr 2022 04:21:05 +0300
1, Some basic services of mysql
1. In the windows operating system, how to use commands to start and shut down mysql services? Syntax: net stop service name; net start service name;
The above commands can be used to start and stop other services.
2. mysql is installed and the service is started. How can I use the client to log in to the ...
Posted by DataSpy on Sat, 02 Apr 2022 03:57:22 +0300
Recently, I received a request (false) to remove the objects younger than 18 years old from the member object in a list. Otherwise, there will be problems after the display.
After you get the demand, you can write it quickly. The logic is also very clear, and the approximate code is as follows:
void removeMember(List<Member> list ...
Posted by libertyct on Fri, 01 Apr 2022 09:38:42 +0300
MySQL index transaction
3. Summary of key contents
MySQL index transaction
An index is a special file that contains reference pointers to all records in a data table. You can create indexes on one or more columns i ...
Posted by bdamod1 on Fri, 01 Apr 2022 09:18:44 +0300
In order to pass some financial security indicators (policy issues) and prevent data leakage, the company needs to encrypt user sensitive data, so all databases storing user information in the company's project need to be encrypted. Including Mysql, redis, mongodb, es, HBase, etc.Because in the project, the springboot+mybatis ...
Posted by bulgin on Thu, 31 Mar 2022 09:00:36 +0300