The keyword "delimiter" is used to declare the delimiter of SQL statement and tell mysql interpreter whether the command has ended and whether mysql can be executed. By default, delimiter is a semicolon;. In the command line client, if a line of commands ends with a semicolon, mysql will execu ...
Posted by danielrs1 on Fri, 26 Jun 2020 18:30:09 -0700
CREATE/ALTER/DROP VIEW ViewName as SELECT(...)
You can continue to create a view based on it, that is, you can place the previously created view as a table name in the select statement of the new view
Format data using views (that is, reassemble and stitch fields)
CREATE VIEW View_player_team AS
SELECT CONCAT(player_name, '(' , t ...
Posted by Izzy1979 on Fri, 26 Jun 2020 09:58:46 -0700
Preface: to every reader: Hello! My name is Changlon. I'm a runner who runs on the road of programming like you, hoping to change the world and improve your life with programming.
First intention of writing article: convenient for review later, convenient for future interview, make more friends, exchan ...
Posted by eflopez on Fri, 26 Jun 2020 01:03:18 -0700
Re operate the old c + + business and get used to the usual database operation mode, so take the time to encapsulate a C + + version of JSON orm. Now it supports sqlit3 and mysql, and postgres is ready.
Our general ORM, the basic pattern is to want to break away from the database, almost all in the programming language level model, ...
Posted by thedarkwinter on Thu, 25 Jun 2020 22:42:57 -0700
Two days ago, we introduced Multi data source configuration of JdbcTemplate as well as Multi data source configuration of Spring Data JPA , let's talk about how to configure the multi data source scenario when using MyBatis.
Add configuration for multiple data sources
First, in the configuration file of ...
Posted by osti on Thu, 25 Jun 2020 19:19:18 -0700
How to use Jdbc and Servlet to operate Mysql database and write Android login server?
1. Download and install Tomcat server
2. Open eclipse and choose Java EE mode
3. Configure Servers
1. Click on the blue word in the bottom configuration box
(2) Select the corresponding versions of Apache and Tomcat in the server type
Posted by itsgood on Thu, 25 Jun 2020 09:13:51 -0700
1, docker: container based Virtualization (hosting applications to application containers) implements an application level resource isolation and quota.
What is a container?Container: lightweight Virtualization (sharing the same system kernel). The container is run by the container image.Advantages: h ...
Posted by mark123$ on Thu, 25 Jun 2020 05:08:49 -0700
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 ...
Posted by LuckyLucy on Wed, 24 Jun 2020 11:21:07 -0700
External exposure port 8066
External exposure port 3306
External exposure port 3306
1. Install mycat
1.1 download the installation package (it is r ...
Posted by ganesh129 on Tue, 23 Jun 2020 22:20:45 -0700
It was introduced in March R2DBC , which is an asynchronous, non blocking relational database connection specification. Although some NoSQL database vendors provide reactive database clients for their databases, migration to NoSQL is not an ideal choice for most projects. This promotes the birth of a general responsive relation ...
Posted by jabapyth on Tue, 23 Jun 2020 18:58:16 -0700