MySQL

Solution:Step 1: the database and table created during restoration are in utf8 format (utf8 is recommended, of course, either gbk or gb2312)Copy codeThe Code is as follows:Create database 'shegongku 'default character set utf8Create table 'members '(

In order to install the mysql environment for testing, it was found that mysql occupied a large amount of virtual memory after the installation, which could reach more than 8 hundred megabytes. I searched for it online and got some tips from my. ini.

A few days ago, I wrote a summary of Mysql cross-Table update. Today, let's take a look at cross-Table deletion.After Mysql4.0, mysql began to support cross-Table delete.Mysql can delete multiple table records in an SQL statement at the same time,

MySQL we have installed is a database management tool. What is really valuable is that data in a relational database exists in the form of tables, the aggregation of N tables becomes a database. Now let's take a look at the basic operations of the

I. innodb row lock Classification Record lock: record lock, that is, only a single row is locked.Gap lock: interval lock. Only one interval is locked. (Note that the interval here is an open interval, that is, the boundary value is not included.Next-

Reading data from text files (import)Common text files: CSV (Comma Separated Values) files, that is, Values Separated by commasThe format is as follows::[Plain]M0001, Li Gang, 1976-01-M0002, Wang Er, 1955-01-15,1M0003, Li Si, 1967-03-[SQL]Load data

InMysqlClient andMysqlThere is a character set converter between servers. Character_set_client => gbk: the converter knows that the client sends the gbk encoding. Character_set_connection => gbk: Convert the data transmitted from the client to the

Here is my experienceThis is generally the case when you first start to learn SQL.Copy codeThe Code is as follows:SELECT * FROM table order by id LIMIT 1000, 10; However, when the data reaches the million level, writing will slow down.Copy codeThe

The index field is too long,1. Modify the Field Length2. Modify the default storage engine of mysql.Add default-storage-engine = INNODB under [mysqld] of/etc/mysql/my. cnfHowever, the INNODB engine must be used for database creation.SQL codeCopy

1. Introduction to stored procedures The commonly used operating database language SQL statements must be compiled and then executed before execution. The Stored Procedure (Stored Procedure) is a set of SQL statements for specific functions, after

I. MySQL stored procedure parameters (in)MySQL stored procedure "in" parameter: similar to the value passing of function parameters in C language, MySQL stored procedure may modify this parameter internally, but modify the in type parameter, not

To check whether the event scheduler is currently enabledShow variables like 'event _ schedount ';Enable Event ViewerSet global event_scheduler = 1;Create eventSyntax:Create event [if not exists] event_nameOn schedule schedule[On completion [NOT]

1. How to create an independent account and Set permissions Here I use Navicat as my database management tool to open Navicat. Select "user" -- "create user" Enter the user name, host, and password. Note that the host name is not "localhost",

Mysql> create table jackbillow (ip int unsigned, name char (1 ));Query OK, 0 rows affected (0.02 sec)Mysql> insert into jackbillow values (inet_aton ('192. 168.1.200 '), 'A'), (inet_aton ('192. 100.30.241'), 'B ');Query OK, 2 rows affected (0.00 sec)

In fact, this statement is not completely correct. First, the key value of query_cache in mysql is not a simple query, but a query with databasename and flag. This can be seen from the source code. I will not describe it here, but I will analyze it

Unsigned is a non-negative number. You can use this type to increase the data length!For example, if the maximum value of tinyint is 127, the maximum value of tinyint unsigned is 127*2.The unsigned attribute is only for integer type, while the

Of course, the emergence of the GUID function of 5.6 has also brought infinite possibilities for multi-master, but this is a digress.This article mainly introduces a non-real-time multi-master Method for MySQL versions.Introduction:The original idea

MySQL has introduced the character set concept since mysql 4.1. Therefore, for MySQL and earlier versions, their character sets are Latin1, so sometimes mysql character sets need to be converted, upgrade or downgrade the MySQL version, especially

I. Download. Here we use the green decompressed version.Http://mirror.services.wisc.edu/mysql/Downloads/MySQL-5.1/mysql-noinstall-5.1.32-win32.zip2. Configure MySQL Parameters1. decompress the green software to D: \ AppServ \ MySQL.Set system

If you want to test it locally, you can download it without points: Use the SQL injection vulnerability to drag the databaseLike the previous article, we need to create a data table and enter several data entries in the table for testing.Create a