How to integrate custom SPI with sentinel to realize fuse current limiting

preface We talked before Talk about how to implement an SPI with interceptor function . At that time, the core idea of our implementation was to use responsibility chain + dynamic agent. Today, let's talk about how to integrate sentinel to realize fuse current limiting through dynamic agent Pre knowledge Introduction to alibaba sentinel Se ...

Posted on Tue, 07 Dec 2021 03:39:45 -0500 by alexinjamestown

Database transaction and connection pool

Database transaction Introduction to database transactions 1. Transaction: a group of logical operation units that transform data from one state to another. 2. Transaction processing (transaction operation): ensure that all transactions are executed as a work unit. Even if there is a fault, it cannot be modified Change this way of execution ...

Posted on Thu, 02 Dec 2021 22:08:52 -0500 by jonsimmonds

Experiment 3: single table query

Experimental purpose Master the application of simple SQL query statements, including the application of conditions, like, top, order by, compute, etcMaster the application of connection query Experimental content 1. Basic query (1) Query all the information of all students in the Student table use student_info; select * from Student; ...

Posted on Tue, 30 Nov 2021 21:54:55 -0500 by servo

SQL Server Database -- creation and use of stored procedures

1, Stored procedure       1. Stored procedure         Stored procedure is a set of SQL statements to complete specific functions. It is compiled and stored in the server-side database. Users execute it by specifying the name of the stored procedure and giving parameters (if the stored procedure has paramete ...

Posted on Sun, 28 Nov 2021 22:43:57 -0500 by BigMike

SQL Server (2019) database -- data query (Introduction to database system, Fifth Edition)

catalogue 1, Textbook example query 1. Query the names of all students and their year of birth 2. The name, year of birth and Department of all students shall be queried, and the Department name shall be expressed in lowercase letters   3. Query the student number of the elective course 4. Query the names and genders of students not ...

Posted on Mon, 22 Nov 2021 04:26:03 -0500 by Phasma Felis

SQL server data query

preface This paper briefly summarizes the data query statements and reviews what I wrote when reading Basic grammar Single line note:-- Multiline comment / **/ 1, Single table query 1. Select several columns in the table --Query specified column select sno, sname from student; --Query all columns select * from student; --Query ...

Posted on Mon, 08 Nov 2021 06:49:09 -0500 by Gorf

Introduction to database system -- database single table query

1, Experimental purpose Master the basic syntax of SELECT statement and the expression method of query conditions;Master query condition expression and usage;Master the function and usage of GROUP BY clause;Master the function and usage of HAVING clause;Master the function and usage of ORDER BY clause. 2, Experimental class hours 2 class hou ...

Posted on Sun, 07 Nov 2021 01:54:28 -0400 by MidOhioIT

[VS] Web page connection database

Tools: 1. Visual Studio (I use vs2019) 2. SQL Server (I use sql2008) 3. Web page running framework:. Net2.0 catalogue 1, The web site connects to the database with windows authentication 2, The website connects to the database with sql server authentication 3, Use the tools to connect to the database that comes with Visual Studio 1, ...

Posted on Fri, 05 Nov 2021 20:42:45 -0400 by arbab

C + + connect to SQL Server database through ODBC and add, delete, query and modify operations [book borrowing system as an example]

C + + connect to SQL Server database through ODBC and add, delete, query and modify operations [book borrowing system as an example] Article catalog preface 1, How to configure ODBC 2, How to set account and password for SQL Server 3, Code implementation of C + + connection to database and addition, deletion, query and modification operati ...

Posted on Wed, 08 Sep 2021 18:02:49 -0400 by quicknik

Analysis of a Bug in your sqldba's lower version

Help people to analyze and solve a problem of your sqldba backup error reporting. I think it's a little interesting. I'll record the analysis ideas. The general solutions are as follows:   First, find the error message of YourSQLDba job yousqldba ﹣ fullbackups ﹣ and ﹣ maintenance or the error log information of the job, and check the error d ...

Posted on Fri, 08 May 2020 06:17:47 -0400 by brianlange