MySql must know and be able to read notes

Chapter 7 data filtering Combine WHERE clause AND operator SELECT prod_price,prod_name FROM products WHERE vend_id = 1003 AND prod_price <=10; OR operator SELECT prod_price,prod_name FROM products WHERE vend_id = 1003 OR prod_price <=10; Calculator counts SELECT prod_price,prod_name, ...

Posted by gckmac on Sun, 23 Feb 2020 13:32:22 +0100

MySQL basic: MySQL data operation

Catalog Add record Update record Delete record Query record WHERE condition GROUP BY multi-table query Create foreign keys Joint query Common mathematical functions of MySQL Common string functions of MySQL Date functions commonly used in MySQL Other common functions Add record # grammar INSERT [I ...

Posted by juancuca on Sun, 23 Feb 2020 08:59:29 +0100

Failure analysis | Crash caused by binlog flush failure

By xuty Open a pit to record the process of MySQL source code tracking and learning due to problem solving needs or interest research. 1, Problem phenomenon MySQL Crash occurs in a project. The related error log logs are as follows. From the logs, it can be seen that the problem is caused by binlog error, but the specific reason can not be c ...

Posted by mars_rahul on Fri, 21 Feb 2020 14:43:21 +0100

3. Querying, adding, deleting and modifying

Article directory First, query 1. Basic query (1) Basic usage (2) Filter data WHERE (3) Sort ORDER BY (4) Character matching query LIKE (5) Query result does not repeat DISTINCT (6) GROUP BY (7) LIMIT query results LIMIT 2. Querying with collection functions (1) COUNT() the total number of rows i ...

Posted by lkq on Fri, 21 Feb 2020 14:23:26 +0100

PDO basic operation of PHP

The difference between PDO and Mysqli For PHP 5 and above, the following methods are recommended to connect to MySQL: MySQLi extension ("i" means improved) PDO (PHP Data Objects) PDO is used in 12 different databases, MySQL is only for MySQL database. Both support preprocessing statements to ...

Posted by Zssz on Fri, 21 Feb 2020 08:49:47 +0100

XML based declarative transaction control configuration steps in Spring

1. Import Maven coordinates <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.0.2.RELEASE</version> </dependency> <de ...

Posted by fiorelina21 on Thu, 20 Feb 2020 07:36:28 +0100

Through Source Code Optimization: How many options do you know for String string performance optimization?

Recommended reading: Ali Liang Jing on both sides: design mode + cache + Spring + virtual machine + MySQL + middleware + concurrency and other problems, all solved Alibaba bytes jump those big factories must ask HTTP how to learn?I suggest you read this article! Ant, byte, PDD social face-to-face via Java post (Distributed + Thread Security + ...

Posted by barrylee on Wed, 19 Feb 2020 19:06:40 +0100

How to use TCP Wrappers to protect MySQL from service interruption

By Ananias Tsalouchidis Translated by: Meng Wei Original text: https://www.percona.com/blog/2020/01/07/how-securing-mysql-with-tcp-wrappers-can-cause-an-outage/ case Protecting MySQL is always a challenge. There are general best practices for installing reinforcement, but the more complex your settings are, the more likely you are to encou ...

Posted by Solarpitch on Tue, 18 Feb 2020 11:08:40 +0100

3-Use databases in Django

Database Settings In the previous section, you learned how to create a Django project, create a web application in a Django project, and reference the URL of a web application in the URL of a Django main program.Here's how to use databases in Django.To use a database in Django, you first need to understand the settings for the database connecti ...

Posted by Sinikka on Sun, 16 Feb 2020 21:48:32 +0100

MySQL query operation

Introduction to MySQL database Learning notes (2) Simple query SELECT column_name1, column_name2 FROM table_name; #select name,phone from person; SELECT * FROM table_name; #select * from person; * indicates all contents in the query table Conditional query where clause is required for condition q ...

Posted by the-hardy-kid on Sun, 16 Feb 2020 05:48:27 +0100