MySQL

First, create a databaseThe SQL syntax format for creating databases in MySQL is:CREATE database name;Where the database name cannot have the same name as the database that already exists. To create a database test_db:You can view the definition of

what is a storage engine?The storage engine is a set of programs that is responsible for translating the user's presentation layer (SQL statement) data into the physical layer (database data file) data. MySQL is a plug-in storage engine. What is a

The MySQL lock contains table-level locks and row-level locks in two large categories. Table-level locks are intent locks, have ix,is, are generally used before row-level locks, and row-level locks are traditional s and x locks. The compatibility

#----The command line to connect to MySQL---------#启动mysql服务器net start MySQL#关闭net stop MySQL#进入Mysql-h host Address-u user name-P user Password#退出Exit#---------------------------#----MySQL User management--------- #修改密码: First, under DOS, enter

Show statusShow status can query the current MySQL server state information. The statement does not require any permissions.For show status you can use the LIKE clause to retrieve the required state information for fuzzy retrieval. Such as:SHOW

Query test table by group_id group SORT_ID Top 100SELECT id AS ‘原数据ID‘,group_id AS ‘分组ID‘,sort_id AS ‘排序条件‘,num AS ‘排名‘FROM (SELECT @row_number := CASE WHEN @customer_no = group_id THEN @row_number + 1 ELSE 1 END AS num

Test table:CREATE TABLE' Test ' (' ID ')int( One) not NULLauto_increment, ' name 'varchar(255) not NULL,`Order' varchar (255)DEFAULT NULL,PRIMARY KEY(' id ')) ENGINE=InnoDB auto_increment=4 DEFAULTCHARSET=UTF8;Insert test data:INSERT into'

1. Install the relevant software:2. Upload the installation package to the Linux system3. Set up MySQL group and account4. Unzip the downloaded package5. Enter the software package, the source code program./configure6.make && make install

(1). master-Slave inconsistency failure, from the library down, after starting from the library to write data repeatedly errorSolutions and Prevention:Relay_log_info_repository=table(InnoDB)Parameter explanation Description:If

Ref: 77638826 -Table structure -CREATE TABLE' Zk_score ' (' ID ')varchar(255) not NULLCOMMENT'Rating Table', ' name 'varchar(255)DEFAULT NULLCOMMENT'Name of Institution', ' TOTALSCR 'varchar(255)DEFAULT NULLCOMMENT'Comprehensive score',

First, the HTTP protocolSecond, HTTPS protocolThird, use Python to get the data(1) Urlib(2) Get request(3) Post requestFour, crawl the Watercress movie actual combat1. Ideas(1) Enter Https://movie.douban.com/j/search_tags?type=movie in the browser

OverviewMySQL is a 关系型数据库 relationship between a stored entity and an entity (that is, a two-dimensional table). is an open source database provided by Oracle Corporation. The Community edition is free and the industry edition is charged. For

In fact, the path has been changed before the path confirmation no problemThen think about MySQL last step configuration fileWe all know that the configuration file chooses the configuration according to the actual situationMy choice is medium.So

Mysql provides us with 4 of data engines:MYISAM, Heap and InnoDB and Berkley (BDB)This highlights the common MyISAM and InnoDBMyiasm engine1.MyIASM is the default engine for MySQL , but it does not provide support for database transactions ,

Creating views: Create View name [(column name 1, column Name 2, ... )] As a complex SELECT statement; View using: SELECT * from view name where Condition order by ..... Modify view: Alter VIEW name [(column name 1, column Name 2, ...  )] AS SELECT

Copy collection private, no other meaning, the original blog address:Https://www.cnblogs.com/walblog/p/9414604.htmlMARIADB is installed by default in CentOS, this is the branch of MySQL, but in order to need, it is necessary to install MySQL in the

As shown, to query a user (from the beginning of the registration) 7 days, 15 days, 30 days of the number of posts, the results of the query data serial.   Because, there are registered users, he did not post 7 days ago, that is, the number of posts

MySQL case sensitive issues under CENTOS7 cause the program to run without finding the corresponding table.Workaround:The first step: Edit the/etc/my.cnf file, add the Lower_case_table_names=1 parameter under the [Mysqld] section, and set the

The CentOS7 Yum source does not seem to have MySQL by default. To solve this problem, we need to download the MySQL repo source first.1. Download the MySQL repo source$ wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm2. Install

Four characteristics, handling1, atomicity (atomicity): All operations after the start of the transaction, or all done, or all do not, it is impossible to stagnate in the middle. An error occurred during the execution of the transaction, and it was