My JDBC learning path

JDBC What is JDBC JDBC (Java database connectivity) is a Java API used to execute SQL statements. It provides unified access to a variety of relational databases. It is composed of a group of classes and interfaces written in Java language Connect database Connect before mysql8 Database driver name: com mysql. jdbc. Driver url connection: ...

Posted by mrhinman on Mon, 09 May 2022 06:28:50 +0300

MySQL index as I understand it

Hello, nice to meet you. Starting from September, I decided to launch the goal of "weekly blog": publish at least one blog every week, which can be a variety of source code analysis and study, or a problem encountered in recording work. After a period of aimless study, I found that it didn't seem to be very useful. I forgot what I had ...

Posted by kid_drew on Mon, 09 May 2022 00:21:49 +0300

SQL language multi table query (oracle)

multi-table query When the queried data does not come from one table, you need to use multi table join to complete the query. Query the associated data according to the relationship between the data in different tables. 1, Cartesian product In mathematics, the Cartesian product of two sets X and y, also known as the direct product, repr ...

Posted by grafnic1732 on Sun, 08 May 2022 20:34:12 +0300

php+mysql+cookie + modular development

PHP PHP output <?php echo "Hello"; echo("Hello"); print("Hello"); print "hello"; var_dump("Contact PHP");//Code debugging uses this Define variables php is a weak reference language, so it's easy to use. data type array 1. Index array subscripts are numbers called index arrays 2. The subscript of associative array is a st ...

Posted by phenley on Sun, 08 May 2022 09:05:26 +0300

SQL basic language collation 2

029 SQL basic query and data update – workbench: Software – query data: select //Query the name of fruit with a price of 10.2 yuan from the fruits table select f_name(,f_price Better look) from fruits where f_price=10.2; – query with in keyword: discrete value //Query s from the fruits table_ Records with IDS 101 an ...

Posted by spamyboy on Sat, 07 May 2022 23:01:58 +0300

Docker installs Redis, and Spring Boot uses Redis to solve the type conversion exceptions in Redis

Dock installs Redis (if installed, please skip this step) 1. Pull Redis image (latest version by default) docker pull redis If the download is slow, it is recommended to configure alicloud image View alicloud image: alicloud official website -- > products -- > search container image service -- > management console ​ Mirror accelerator ...

Posted by asuperstar103 on Fri, 06 May 2022 23:50:35 +0300

hydd's LInux notes Day61

Day61 Overview of MHA cluster MHA introduction Introduction to MHA MHA(Master high Availability) It is developed by DeNA company in Japan. It is an excellent solution to realize high availability of MySQL. The automatic failover operation of the database can be completed within 0 ~ 30 seconds. MHA can ensure the consistency of data to the ...

Posted by eva21 on Thu, 05 May 2022 22:26:27 +0300

Detailed explanation of Redis related commands and their principles: Redis basic operations, data structures and applications

How to learn redis? Learn what redis isHow to use redis, how to operate the data structure in redisTypical applications and operationsRead the redis source code 1. Redis Redis is the abbreviation of Remote Dictionary Service; it is also a remote dictionary service; Redis is an in-memory database, KV database, data structure database; Red ...

Posted by cryp7 on Thu, 05 May 2022 16:53:18 +0300

Install mysql-5.7.28-linux-glibc2.0 in CentOS 7 12-x86_ 64.tar. gz

1 check whether mysql service is installed by default in the system. If so, uninstall it. 1) Check command rpm -qa|grep mysql 2) Uninstall command rpm -e --nodeps mysql-libs-5.1.73-7.el6.x86_64 2 if it is CentOS 7, a mysql branch database mariadb will be installed by default. You must uninstall this database first 1) Search rpm -e --node ...

Posted by newbie5050 on Thu, 05 May 2022 10:21:04 +0300

JDBC [1] - primary addition, deletion, modification and query

[TOC] 1. What is JDBC JDBC (Java database connectivity) is a Java API for executing SQL statements. It can provide unified access to a variety of relational databases. It is composed of a group of classes and interfaces written in Java language. JDBC provides a benchmark by which more advanced tools and interfaces can be built to enable databa ...

Posted by arth on Thu, 05 May 2022 08:55:55 +0300