MySQL

Mysql alter statement usage some syntax ADD field: alter table table_name ADD field_name field_type; modify the original field name and type: alter table table_name CHANGE old_field_name new_field_name field_type; www.2cto.com Delete field: alter

Mysql database Chinese garbled solution when we write a program, sometimes even if we set the page content encoding to UTF-8 OR gbk on the jsp page and code,However, when we store data, we find that the data in the database is garbled, and the

Create a new user in mysql and grant permissions 1. log on to mysql-u root-p as an administrator 2. Select mysql database www.2cto.com use mysql 3. Create a user and set the password insert into user (Host, user, Password) values ('localhost', 'test'

Configuring vsftpd with PAM_MySQL this blog explains how to use pam_mysql to configure vsftpd, provided that you have installed mysql and some of its services. If not, please refer to other tutorials on the network. This article focuses on the

MySQL date and time functions use the following query to SELECT all records. The value of date_col is within the last 30 days: mysql> SELECT something FROM table WHERE TO_DAYS (NOW ()) -TO_DAYS (date_col) select DAYOFWEEK ('1970-02-03 ');-> 3

Mysql time processing function DAYOFWEEK (date) returns the index of the week of the date (1 = Sunday, 2 = Monday ,... 7 = Saturday ). These index values correspond to the ODBC standard. Mysql> select DAYOFWEEK ('1970-02-03 ');-> 3 WEEKDAY (date)

MySQL command line data operation experience (Summary) Char 0 ~ 255 Varchar 0 ~ 65535 text 0 ~ 65535 (only characters can be saved) www.2cto.com Longtext 0 ~ 4294967295 (only characters can be saved) CMD login mysql-u root-p mysql-P 3306-uroot-p12345

MySQL Installation Summary: The Start service did not respond (Win7 64-bit) Many people encountered problems on the internet because MySQL was installed on the machine before, and the original information may not be deleted. I don't know why MySQL

Mysql mybatis returns the inserted primary key id [html] insert into T_Company_Info (Company_Id, IsFranchisee, Company_Code, Company_Name) values (# {companyId}, # {isfranchisee}, # {companyCode}, # {companyName }) SELECT LAST_INSERT_ID () as id

In Linux, Mysql is case-sensitive. 1. After mysql is installed in Linux, It is the default value: case-sensitive for table names, not case-sensitive for column names. 2. After logging on with the root account, in/etc/my. add "lower_case_table_names =

How to use indexes in most databases and store indexes using the structure of B-Tree. Www.2cto.com B tree, top node: Root Node bottom node: leaf node between the two nodes: middle node B tree, significant features: slave node, the distance to each

Command mysqldump-hhostname-uusername-ppassword databasename> backupfile to back up MySQL database. the SQL backup MySQL database is in the format of a table with deletion. the MySQL database is in the format of a table with deletion. This allows

When inserting a record, let the sort value be the maximum value of the number of child nodes under the parent id plus 1 and seldom write database statements. A very simple statement can be thought of for a long time. In fact, it also means that you

MySQL 5.5 creates a linear Hash Partition Table and distributes the table files to different physical disks. Data on different servers must be merged. Considering that the game zone group server will be added continuously in the future, therefore,

How to use commands to view the Mysql database size 1. Enter the specified schema database (storing information of other databases) www.2cto.com 1use information_schema2. query the size of all data 1 select concat (round (sum (DATA_LENGTH/1024/1024),

How to delete a 7G large table online without affecting the performance? How to delete a 7G (or larger) large table in the mysql database without affecting the I/O of the server? As a result, performance degradation affects the business. Not to

Instructions for importing txt file data in mysql learning and summarizing basic MySQL database import and export operations www.2cto.com 1 TABLE tt format: create table 'TT' ('ind 'int not null auto_increment, 'name' char (100) default NULL,

Common Xtrabackup parameters during Hot Backup are as follows: -- defaults-file = # default configuration file path. If the parameter is not set, xtrabackup searches for the configuration file/etc/my. cnf,/etc/mysql/my. cnf,/usr/local/etc/my. cnf ,~

Modify the root password of mysql and assign permissions. for example, if my Mysql is installed in the E: \ xampp \ mysql directory win7 and CMD is used, the command line uses the password-free root user to log on to the mysql database. The red font

The installation and configuration process of mysql5.6 began in May. The mysql official website began to release various versions of mysql 5.6 series. The version of mysql5.6 series was further refined; in my opinion, the following is a sharing