MySQL

Install MySQL Sudo apt-get install mysql-server This should be very simple, and I don't think there is much problem with the installation, so I will not talk about it much. Let's talk about the configuration below. Configure MySQL Note: In Ubuntu,

1. Question about re-assigning the initial value of an auto-increment field?　　 ALTERTABLEtblAUTO_INCREMENT = 1;　　 2. How to Implement the function of adding fields in mysql?　　 Createtableabc (idint (10) notnullauto_incremnetprimarykey,　　 Namevarchar

Regular MySQL backup is an important task, but manual operations are too cumbersome and difficult to avoid any omissions. You can use the following method to regularly back up data.◆ 1. Create a backup folder# Cd/www# Makedir backup◆ 2. Compile the

The database optimization tutorial of the Helper House (www.bkjia.com) is very complicated, because it requires a good understanding of system optimization. Although the optimization effect is good if you do not know much about the system or

Using MySQL for database backup has a very regular database backup method, which has the same concept as other database servers, but have you ever thought about it, mySQL will have a simpler backup method using the file directory, and it will be

My personal practice is: phpmyadmin exports abc. SQL in UTF-8 insert mode Ftp abc. SQL to serverSsh to serverMysql-u abc-p use KKK (database name, if not, create database KKK) set names 'utf8' source abc. SQLNote: I have seen the set character set

1. When creating a MySQL table, the field must be set to a non-empty value and the default value of the field must be set.2. When creating a MySQL table, if the field needs to be NULL, you need to set the default value of the field. The default

The Mysql database provides two types of indexes. If they are not correctly set, the index utilization efficiency will be greatly reduced, but the problem is completely unknown.Copy codeThe Code is as follows:Create table test (Id int not

The coalesce function can accept multiple parameters and returns the first non-NULL value of these parameters. If all the provided parameters are NULL, NULL is returned.The ifnull function is the same as the coalesce function, but only two

1. Inner join(Typical join operations use comparison operators such as = or <> ). Including equal join and natural join.The inner join uses the comparison operator to match rows in two tables based on the values of the columns in each table. For

The default Scheduling Policies of MySQL can be summarized as follows:· Write operations take precedence over read operations.· Write operations on a data table can only occur once at a time point, and write requests are processed in the order they

2 points firstEnabling cache also brings about overhead, mainly in the following aspects:Before starting the query, you must check the cache.If the query is cached but not in the result set, saving the data after the result is generated will incur a

Query is the core of the database. The following describes how to implement Mysql multi-Table query. If you have encountered any problems in Mysql multi-Table query, take a look.Mysql multi-Table query:Copy codeThe Code is as follows:Create table if

When creating a foreign key in MySQL, an ERROR is prompted, but only the simple information is prompted: ERROR 1005 (HY000): Can't create table 'db _ qxztc. qx_userssssnew' (errno: 150 ). It cannot solve the problem at all. To view the detailed

I believe most people have encountered too many instances to install mysql. I believe most people only need to find a multi-instance installation tutorial and it will be easy to solve, but the more smooth the installation process, the more

Select * from table limit m, n where m Refers to the index at the beginning of the record, starting from 0, and n refers to taking n records starting from entry m.Copy codeThe Code is as follows:Mysql (root @ localhost: test)> select * from total;+ -

When I visited the Forum today, I found a seemingly simple problem, but it attracted wide attention:This is a very early interview question:A table contains an ID auto-incrementing primary key. After 17 records are inserted, records 15, 16, and 17

The project needs to re-install a mysql server on the existing server. It is quite difficult, because it was previously tested on my laptop and its system is Ubuntu, what is the path and the startup method. They are all different, so this time I am

After getting started with replication, I began to think about how to configure and try it. Although there were a lot of problems: I had to check the information on the Internet and finally solved some problems. now I will share my experiences:The

BEGIN Declare date_str varchar (8 );Declare table_prefix varchar (20 );Set table_prefix = 'mail _ rare_visit _';Set date_str = DATE_FORMAT (CURRENT_DATE (), '% Y % m % D ');Set @ table_name = concat (table_prefix, date_str );Set @ s = concat