MySQL

# mysqladmin Flush-hosts Now we go into the MySQL editor my.cnf # VI/ETC/MY.CNF Then add in the inside max_connect_errors=10000 # Service Mysqld Restart Then restart the MySQL database server, if you do not have the server permissions we can

MySQL Bulk substitution specified field string statement UPDATE data table name set field name = Replace (field name, ' String to replace ', ' replace with ') WHERE set condition; Example The code is as follows Copy Code

1. Query, can not use * do not use, try to write full field name. 2. The more indexes are not the better, each table is controlled within 6 indexes. The index does not work in the case of a range where condition, such as where value 3. In most

Inquire The code is as follows Copy Code SELECT * FROM table1 WHERE table1.id in (1, 2, 3, 4, 5, ..., 999999) Delete The code is as follows Copy Code DELETE from ' table1 ' WHERE '

Human flesh update is a very scary thing. So I searched for a way to use the MySQL batch replacement field! 1. Use phpMyAdmin to enter the database management, search http://wenwen.soso.com, you can see which tables contain this field.2. Click SQL,

I wrote a random test.php. Linked database test, the results show: Could not connect:mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use a administration tool to reset your password with the command SET

Below we understand some MySQL optimization foundation, MySQL optimization I divide into two parts, one is the server physical hardware optimization, the second is the MySQL itself (my.cnf) optimization. The impact of server hardware on MySQL

1 case sensitivity of authorization table range columns+--------------+-----+-----+---------+----+-----------+------------+| Column | Host | User | Password | Db | table_name | column_name || Case Sensitivity | No | Yes | Yes | Yes | Yes | No |+-----

Mysql ifnull operation Project, the value in the query results is set to the default value when the SQL query field is empty. The most stupid way of course is to process the query results, traversing the query results, when empty, set its value:

One, correct configuration file, clear cache 1. In the face of this problem, do not rush to reinstall the MySQL database, in fact, the solution is very simple, people need to clean up the Windows cache directory on it.2. Press "Windows key +r" to

So how do you solve the sorted output of the grouped data according to the DESC of the primary key? There are two ways of answering: 1, the use of subqueries first sorted the table, and then the Word table for group by query, the resulting column

One, uptime can view the running time of the system Show global status like ' uptime '; Second, use the Linux command to view [Root@dbserver ~]# ps aux | grep MySQLRoot 29090 0.0 0.0 70232 1364? S Jun05

SQL Lock table Reconciliation lock MySQL Tutorial statement For MySQL, there are three types of lock levels: page level, table level, row level The typical page-level representative engine is BDB.The typical representative engine for the table

Table structure:Copy code code as follows:----The structure of the table ' category '--CREATE TABLE IF not EXISTS ' category ' (' id ' int (one) not NULL auto_increment,' Type ' int (one) not NULL COMMENT ' 1 for Article Type 2 for product Type 3

Calculate the number of yearsIf you want to calculate the age of the person by birth, you can use the following statement: SELECT Date_format (From_days to_days (now ())-To_days (@dateofbirth)), '%Y ') + 0; 2. Two difference in timeGets the

Setting up a MySQL configuration file /etc/mysql/my.cnfFind Bind-address =127.0.0.1 to comment it out;//function is to make it no longer allowed only local access; Restart Mysql:/etc/init.d/mysql restart; Access to MySQL Database Mysql-u

1. The capacity of the data: how many data in 1-3 years, how many bytes per piece of data; 2. Data items: whether there are large segments, the values of those fields are often updated;3. Data query SQL Condition: Which data item's column name

MySQL tutorial sexplain syntax and usage Explain [extended] select ... from ... where ... If extended is used, then after the explain statement is executed, you can use the show warnings statement to query the corresponding Optimization

(1) mysql_connect (host, user name, password );Returns a connection number.Note: the passwords of mysql users can change with the IP address of the user's machine.In addition, mSQL does not have a user name mechanism, so msql_connect only needs one

Environment: CentOS 6.5 64-bit1. Download the installation package http://dev.mysql.com/downloads/mysql/5.5.html#downloadsHttp://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.49-linux2.6-x86_64.tar.gz 2. Install MySQLNote: The installation package