mysql change field name

In mysql, we only need to use alter to modify the data table fields. Below I will introduce how to modify the table field name, field length, and field type in mysql, for more information, see. Let's take a look at common methods. The simple Syntax

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

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

Let's take a look at the usual methods. MySQL's simple syntax, commonly used, but not easy to remember. Of course, these SQL syntaxes are basically generic in each database. Listed below: 1. Add a field ALTER TABLE user add COLUMN new1 VARCHAR

MySQL field name conflicts with reserved words and the solution, mysql Field Problem: Conflicts between MySQL field names and reserved words often occur in actual operations. Com. mysql. jdbc. exceptions. jdbc4.MySQLSyntaxErrorException. Solution:

Requirements: Change the MySQL data data file directory and My.ini location.Steps:1. Find the My.ini location, and you can get the My.ini path by viewing the executable file path, which corresponds to its properties, through the MySQL startup entry

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,

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

1. Add a field ALTER TABLE user add COLUMN new1 VARCHAR (x) DEFAULT NULL; 　　 Add a field that defaults to null ALTER TABLE user add COLUMN new2 VARCHAR (a) not NULL; 　　　　　　　　　　　　　　 Add a field, default cannot be empty//2. Delete a field ALTER TABLE

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