MySQL

This time to customers to install test Ineedle equipment, but the installation will not immediately have data display, can not be fully displayed to the user web interface of some information. At this time need to have a public network server to

--single-transaction mysqldump, don't lock the table–NO-DATA Backup Structure onlyBack up a MySQL database (some) tableMysqldump-hhostname-uusername-ppassword databasename specific_table1 specific_table2 > Backupfile.sqlMysql>use DatabaseThen use

When using the Tomcat server link MySQL database, not only need to import the MySQL driver jar package in the project, also need to import the MySQL driver jar package in the Tomcat server's Lib directory, Copy and paste the MySQL driver jar

Let's start with the syntax for limit in MySQL:-- Syntax: SELECT * from Table [offset,] | Rows Offset Offset--Example:Select*from table limit 5; -- return first 5 rows select * from table limit 0,5; -- Ditto, return to the first 5 rows select Span

The following information is derived from: http://dev.mysql.com/doc/refman/5.6/en/windows-create-option-file.html The whole process is divided into the following steps:  one, Extract The archive to the desired install directory, this is nothing to

Backup: Mysqldump-uroot-p YYZC Department >/home/admin/yyzc_backup.sqlRecovery: Mysql-uroot-p Yyzc Back up all databasesMysqldump-uroot-p--all-database > All.sqlBack up the database testMysqldump-uroot-p Test > Test.sqlBack up the table EMP under

Start the database service/etc/init.d/mysqld startInitial security settings:Keep only one record that allows the root user to connect locallyDelete from Mysql.user where (User,host) isn't in (select ' Root ', ' localhost ');Modify the root user name

How to interact with RDBMS using the programming language:Embedded SQL: Similar to dynamic SQL, but its language must be fully determined at the time of program compilationDynamic SQL: Programming language usage function (mysql_connect ())Table

Use Xmapp to start MySQL times wrong:2015-10-22 10:07:32 4904 [note] innodb:database is not shutdown normally!2015-10-22 10:07:32 4904 [note] Innodb:startin G Crash recovery.2015-10-22 10:07:32 4904 [Note] innodb:reading tablespace information from

Ps:innodb This engine is very different from the MyISAM engine. In particular, its data storage format. For the data structure of INNODB, there are two conceptual issues to be solved first: shared tablespace and exclusive table space.1. What is a

1. Change the Table methodX:\>mysql-u Root-pvmwaremysql> use MySQL;mysql> Update user Set host = '% ' where user = ' root ';Mysql> Select Host, user from user;mysql> flush Privileges;Note:mysql> flush privileges; Make the changes effective.2.

1. Change the Table methodX:\>mysql-u Root-pvmwaremysql> use MySQL;mysql> Update user Set host = '% ' where user = ' root ';Mysql> Select Host, user from user;mysql> flush Privileges;Note:mysql> flush privileges; Make the changes effective.2.

First, Bolb and text typesBoth Bolb and text are string data types designed for storing large nowhere and are stored in binary and character mode, respectively.They belong to two different sets of data type families: Character type, binary

To view the current slow-scan log status: Show variables like '%slow% '; #主要关注三个变量: Slow_query_log #是否启用slow_query_log_file #日志文件 # time threshold for slow check show variables like ' Long_ Query_time '; To configure the Enable slow scan log:# # Vim

MySQL's order by it involves three parameters:A. sort_buffer_size sort Cache.B. Read_rnd_buffer_size the second sort cache.C. The maximum sort constraint for max_length_for_sort_data.Let me just briefly say MySQL's sort rules. If the query statement

--Encapsulate several SQL statements, a name called a procedure, and a function that has no return value--storing the process in a database--stored procedure--the creation process of the stored procedure create PROCEDURE Proceducename () Beginsql

/*SELECT Count (*) from (*/EXPLAINSELECTSt.id,st. Stu_name,tmpgt.time,tmpgt.goutong fromJingjie_students St Right JOIN (SELECT * from_goutong Gttime, (SELECTname_id NameID,Max(time) time fromT_goutongGROUP byNAME_ID)

Recently done things using MySQL to do query sorting, but has been the problem, mainly occurs in the query when the memory is always increasing, each increase in memory size is the same,Find a lot of information to know that the original was used

The INFORMATION_SCHEMA database in MySQL is particularly notable for the following points.1, even a newly created user, that is, this user has only one usage permission. It can view some of the tables in Informatoin_schema.2. Try to grant the grant

Unique indexEmphasis is unique, that is, the index value must be unique.Create unique index [index name] on table name (column name);ALTER TABLE name add unique index [index name] (column name);To delete an index:Drop index index name on table