"Mysql" Beginner Command line Guide

MySQL Beginner usage Guide and introduction

• One, connect MySQL

Format: mysql-h host address-u user name-P user Password
1. Example 1: Connect to MySQL on this machine.
First open the DOS window, and then enter the directory Mysqlbin, and then type the command mysql-uroot-p, enter after the prompt you to lose the password, if just installed MySQL, superuser root is no password, so directly enter into MySQL, The prompt for MySQL is: mysql>
2. Example 2: Connect to MySQL on the remote host. Assume that the IP of the remote host is: 110
.110.110.110, user name is root, password is abcd123. Type the following command:
Mysql-h110.110.110.110-uroot-pabcd123
(Note: You and root can be used without spaces, others are the same)
3. Exit MySQL command: Exit (enter)

• Second, change the password

Format: Mysqladmin-u username-P Old password password new password
1, Example 1: Add a password to root ab12. First enter the directory Mysqlbin under DOS, and then type the following command (password do not add a command character)
Mysqladmin-uroot Password AB12
Note: Because Root does not have a password at the beginning, the-p old password can be omitted.
2, Example 2: Then change the root password to djg345.
MYSQLADMIN-UROOT-PAB12 Password djg345

• Third, add new users. (Note: Unlike the above, the following is because it is a command in a MySQL environment, so it is followed by a semicolon as a command terminator)

format: Grant SELECT on database. * To User name @ login host identified by "password"
Example 1, add a user test1 password for ABC, so that he can log on any host, and all databases have query, insert, modify, delete permissions. First, use the root user to connect to MySQL, and then type the following command:
Grant Select,insert,update,delete on * * to [e-mail protected] "%" identified by "ABC";
But example 1 increases the user is very dangerous, you want to like someone to know test1 password, then he can be on any computer on the Internet to log on your MySQL database and to your data can do whatever, workaround see Example 2.
Example 2, add a user test2 password for ABC, so that he can only login on localhost, and the database mydb can query, insert, modify, delete operations (localhost refers to the local host, that is, the MySQL database host), This allows the user to use a password that knows test2, and he cannot access the database directly from the Internet, but only through a Web page on the MySQL host.
Grant Select,insert,update,delete on mydb.* to [e-mail protected] identified by "ABC";
If you do not want to test2 have a password, you can call another command to erase the password.
Grant Select,insert,update,delete on mydb.* to [e-mail protected] identified by "";

　　

In the previous article we talked about login, add user, password change and other issues. In the next section, we'll look at MySQL's operations on the database. Note: You must first log in to MySQL, the following actions are performed at the prompt of MySQL, and each command ends with a semicolon.

• First, the Operation skill

1, if you hit the command, enter after the discovery forgot to add a semicolon, you do not have to re-play the command, as long as a semicolon to enter the return on it. In other words, you can break a complete command into a few lines, and then use a semicolon to make the end sign OK.
2. You can use the cursor up and down keys to recall the previous command. But previously I used an old version of MySQL that was not supported. I'm using Mysql-3.23.27-beta-win now.

• Second, show the command

1. Display the list of databases.
show databases;
Just started with two databases: MySQL and test. MySQL Library is very important it has the MySQL system information, we change the password and the new user, is actually using this library to operate.

2. Display the data table in the library:
Use MySQL;//Open the library, learn foxbase must not be unfamiliar with it
show tables;
3, display the structure of the data table:
describe table name;
4, build the library:
CREATE database name;
5, build the table:
Use library name;
CREATE TABLE table name (field settings list);
6. Deleting the library and deleting the table:
drop database name;
drop table name;
7. Empty the records in the table:
Delete from table name;
8. Display the records in the table:
select * from table name;

• A city build and build tables and instances of inserting data

drop database if exists school;//Delete if school is present
CREATE database School;//Build Library School
Use School;//Open Library School
CREATE TABLE teacher//Create tables Teacher
( 
ID int (3) auto_increment NOT NULL primary key,
name Char (TEN) is not NULL,
address varchar (+) Default ' Shenzhen ',
Year date
); End of Build table
//Below is the Insert field
INSERT into teacher values (' ', ' Glchengang ', ' Shenzhen One ', ' 1976-10-10 ');
INSERT into teacher values (' ', ' Jack ', ' Shenzhen One ', ' 1975-12-23 ');

Note: In the table under construction

(1) Set the ID to a numeric field of length 3: Int (3) and let it automatically add one to each record: Auto_increment cannot be empty: NOT null and let him be the main field primary key

(2) Set name to a character field of length 10

(3) Set address to a character field of length 50, and the default value is Shenzhen. What is the difference between varchar and char, only to wait for a later article to say.

(4) Set year as the Date field.
It is also possible to type the above commands at the MySQL prompt, but it is not easy to debug. You can write the above command as-is to a text file, assume that it is school.sql, then copy it to C: \ and enter directory \mysql\bin in DOS, and then type the following command.
Mysql-uroot-p Password < C:\school.sql
If successful, empty a row without any display, and if there is an error, there is a hint. (The above command has been debugged, you can use it only if you remove//comment).

• Iv. transferring text data to the database

1, the text data should conform to the format: The field data is separated by the TAB key, the null value is replaced by \ n.
Cases:
3 Rose Shenzhen II 1976-10-10
4 Mike Shenzhen one 1975-12-23
2, the data incoming command, load data local infile "file name" into table table name;
Note: You might want to copy the file to the \mysql\bin directory, and use the using command to hit the library that contains the table.

• V. BACKUP DATABASE: (command executed in DOS \mysql\bin directory)

Mysqldump--opt SCHOOL>SCHOOL.BBB
Note: Back up the database school to the school.bbb file, school.bbb is a text file, the filename is taken, open to see what you will find.

Mysql Beginner Command-line guide