MySQL

Reset MySQL Self-add auto_increment initial valueNote that existing data is deleted by using any of the following methods. Method One: Delete from tb1; ALTER TABLE tbl auto_increment = 100; (Benefits, you can set auto_increment to start with any

SELECT * FROM table limit m,n where M is the index at which the record starts, from 0, N is the beginning of article M, and N is taken. Copy Code code as follows: MySQL (root@localhost:test) >select * from Total; +----+-----------------+-

There is a statistical need for IP classification statistics, MySQL provides Inet_aton () and Inet_ntoa () function process processing.The official manual can be viewed in detail. Inet_aton (expr)Gives a point address representation of a network

Poor SQL query statements can have a serious impact on the operation of the entire application, not only consuming more database time, but also impacting other application components. As with other disciplines, optimizing query performance largely

We know that we can put a large number of records of MySQL big table according to the primary key, Time field, conditional field, etc. into several tables and even saved in several servers.The only problem is that the query is cumbersome across

There are indexes and error-proofing mechanisms on the surface of database tables, but a simple query can take a long time. Web applications may work well in the development environment, but they are equally bad in the product environment. If you're

Last night received customer service mm phone, a user feedback database response is very slow, the phone received load abnormal alarm, boarded the host found that a large number of SQL execution is very slow, some more than 10s execution

Environment: Pc:ubuntu 10.10 192.168.1.112 (master) 192.168.10.245 (slave)Mysql:5.1.49-1ubuntu8.1-logDatabase test already exists in master First Modify MySQL configuration file:/etc/mysql/my.cnf[Master] #author: Zhxia Copy Code code as

There are many hint of table joins that can be specified in Oracle: ordered hint instructs Oracle to connect according to the order of the tables following the FROM keyword, leading hint instructs the query optimizer to use the specified table as

1. Create a column ALTER TABLE tablename add COLNAME type NOT null default ' 0′; Cases: ALTER TABLE Mmanapp_mmanmedia add appid_id integer NOT null default 372; 2. Delete Column ALTER TABLE tablename drop

Problem User work Order question: The same statement, only the last limit line number is different. Oddly, the performance of limit 10 is about 10 times times slower than the Limit 100 statement. Hide User table information, statements, and the

Occasionally to use PHP to do some MySQL database operation Test, write yourself too troublesome, the results of the search generally contains a lot of useless code, here will be PHP MySQL operation to do a summary, I hope that in the future when

Most use WordPress built site, after the table are MySQL database, often we need to customize the function of WordPress, here we list 10 most useful wordpress database query, you need a database management tools, such as phpMyAdmin or NAVICAT, etc.

The primary key in a table originally was an int self-growing type,Because business changes require an int to be converted to a CHAR-type primary key. Also, because the data already exists in the original table, you cannot delete the table rebuild,

Recently and Sobin are doing a project for a boutique course, because a fixed ID is used as an association between tables, so after inserting data into the previous table, you pass the ID of the inserted data generation to the next table. Studied a

First of all, I used the version number of MySQL is 5.5.17, recently encountered the problem is in eclipse through JDBC to the database to write Chinese data, in the database is displayed?? That garbled, in order to solve this problem, engaged in a

mysql_query ("Begin");/Start a transaction mysql_query ("SET autocommit=0"); Set transaction not automatic commit $insert = "INSERT INTO UserInfo VALUES (' aa12 ', ' AA ', ' 1 ', ' aaa ')"; mysql_query ($insert); mysql_query

If you want to partition on a table that has already been built, MySQL prompts for an error if you add the partition using alter: Copy Code code as follows: ERROR 1505 Partition Management on a not partitioned the table is not

Query is the core of the database, the following for you to introduce MySQL multiple table query How to achieve, if you are in the MySQL multiple table query has encountered problems, may wish to see. mysql multiple table query: Copy Code

The default scheduling policy for MySQL can be summarized as follows:· Write operations take precedence over read operations.· Writes to a data table can occur only once at a time, and write requests are processed in the order in which they arrive.·