Apache Flink Zero Foundation Initial Flink Custom Sink

Requirement: Data sent by socket, converting String type to object, and then saving Java object to Mysql database. Create databases and tables create database imooc_flink; create table student( id int(11) NOT NULL AUTO_INCREMENT, name varchar(25), age int(10), primary key(id) ) Import mysql dependencies: <dependency> <g ...

Posted on Tue, 01 Oct 2019 13:09:43 -0400 by phpdolan

Multi-table Association Query in Yii2

Preparations: 1. First prepare two tables: customer (user table) (id, name) Order (order form) (id, customer_id, price) There is a one-to-many relationship between the customer table and the order table, which is associated through the customer_id field. 2. Establish the corresponding model files customer.php and order.php.   Associated ...

Posted on Mon, 30 Sep 2019 16:03:27 -0400 by thiggins09

Bootstrap Table Backend Paging

The front-end paging has been used before. In the case of not too much data, the front-end paging is still very convenient. It can also use its own search function. If the amount of data is large, the back-end paging should be used. The principle of implementation: the front end sends offset and limit (the number of pages displayed) to the bac ...

Posted on Mon, 30 Sep 2019 14:41:23 -0400 by snicolas

MySQL 5.7 Replication Delay sync_relay_log

I. descriptionMySQL 5.7 version master-slave replication, batch display delay tens of thousands of seconds. Two, phenomenon 1,io High utilization rate #iostat -dxm 1 1000 Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util scd0 0.00 0.00 0.00 0.00 0.00 0.00 ...

Posted on Mon, 30 Sep 2019 13:24:28 -0400 by satant

Snail Climbing Journey: 5. springboot Slf4j Log Management

Learning springboot's journey is like snail climbing a mountain, climbing up a little bit, and enjoying the scenery of the journey a little bit. Continue Last chapter As a programmed ape, sometimes it is inevitable to dig a hole. At this time, you need a log manager (short for Xiao Mi - Hey, you under ...

Posted on Mon, 30 Sep 2019 07:44:35 -0400 by metin

Web From data migration from Drupal 7 to Drupal 8

Migration ideaWrite Sql in Drupal 8 environment to check all the data under Drupal 7, and then organize the data structure to call Drupal 8 API to insert the data into Drupal 8 database. Migration steps Configure the Database Connection Environment Modify the set.php file of Drupal 8 site // Drupal 8 database link $databases['default']['defaul ...

Posted on Mon, 30 Sep 2019 05:34:25 -0400 by fireice87

30 Cases of SQL Query Syntax

Learn SQL query well: no other, you are familiar with it. 1. Base table: Student table: Teacher's table: Class Schedule Card: Achievement Sheet: 2. Title: 1. Query the information of students whose names contain the word "Hua" select * from Student where sname like '%China%' 2. Query and count the number of students of the same age se ...

Posted on Sun, 29 Sep 2019 23:42:08 -0400 by Bigun

Reflections on PHP Memory Overflow

background Recently, when we do a lot of data export and data import, we often encounter the problem of PHP memory overflow. After solving the problem, we summarize some experience and record it in articles. Optimization point Optimize the SQL statements, avoid slow queries, reasonably index, query the specified fields, SQL optimization is not ...

Posted on Thu, 26 Sep 2019 05:21:25 -0400 by rodin

@ Principles of Transactional Annotation for Transaction Management

I. Introduction In real projects, we usually use the @Transactional annotation to control transactions with Spring. The use of this annotation is very simple. It condenses the tedious transaction control of the original jdbc into the use of this annotation. With the mentality of "knowing what it ...

Posted on Thu, 26 Sep 2019 00:47:35 -0400 by szalinski

Making mysql Big Data Table to Verify Coverage Index

Yesterday, I talked to my colleagues about the performance of data tables. Can we use only overlay index to collect data? To test the existing tables in a development environment, we can see that mysql can achieve the requirements of sum by overwriting the index without reading the actual row data through the explain ing command. However, the ...

Posted on Wed, 25 Sep 2019 04:58:32 -0400 by Morpheus