mysql update field

1. Display the list of databasesshow databases; # View all current databasesShow Databases \g #以行的方式显示2. On the command line, execute the SQL statementMysql-e ' show databases '-uroot-p123456mysqlshow-uroot-p123456 # not used, just remember the one

// Primary key alter table tabelname add new_field_id int(5) unsigned default 0 not null auto_increment ,add primary key (new_field_id); // Delete a column alter table t2 drop column c; // Rename a column alter table t1 change a b integer; // Change

MySQL常用指令，java，php程序员，数据库工程师必备。程序员小冰常用资料整理MySQL common commands (for reference)The most common display commands are:1. Display the list of databases.show databases;2. Display the data table in the library:Use MySQL;Show tables;3, display the

First MySQL updates a field of data, which is generally written like this: UPDATE mytable SET myfield = ' value ' WHERE Other_field = ' other_value '; You can also use in to specify the records to update: UPDATE mytable SET

One: Field modifier1:null and NOT NULL modifiersLet's take a look at this example.Mysql> CREATE TABLE worker (ID int not null,name varchar (8) Not null,pass varchar (a) not null);Mysql> INSERT into worker values (1, ' HA ', ' 123456 ');Mysql> INSERT

I've had a bit of trouble lately. Newly installed PHPwind6.0 official version of the community before the introduction of the member account data, found that many members of the mail address seemingly random fill in, before the PHPwind5.5 version

1. download MySql 1. download MySql Open http://www.mysql.com/downloads/mysql/#downloads download in browser My downloaded version is Red Hat 5 version of http://www.mysql.com/downloads/mirror.php? Id = 407552 Upload the file to the server, or

One, MySQL installationInstall MySQL under CentOS Please open: http://www.centoscn.com/CentosServer/sql/2013/0817/1285.htmlIi. several important directories of MySQLMySQL installation is not as if SQL Server is installed by default in a directory,

Pessimistic locking, as its name implies, is a conservative attitude to the data being modified by the outside world (including other transactions currently in the system, as well as transactions from external systems), so that the data is locked

I. Commonly Used MySQL command line commands1. Start the MySQL service. Net start MySQL Stop MySQL service. net stop MySQL 2. netstat-Na | findstr 3306: Check the listening port. findstr is used to check whether the following port exists. 3. log on