SQL injection -day15

3、 ... and 、Mysql Inject

3.1 necessary

3.1.1 Meta database  information_schema

Meta database information_schema in ：

A table for storing database information ：schemata

schemata In the table ：

Field schema_name Store all Database name ;

A table that stores table information ：tables

tables In the table

Field table_name Store all table names

Field table_schema The name of the database where all tables are stored ;

A table that stores all field information ：columns

columns In the table

Field column_name Store all field names ,

Field table_name The table name where all fields are stored ,

Field table_schema The name of the database where all fields are stored ;

a. information_schema In the database tables What's in the table ： 

b. infomation_schema database columns What's in the table ：

3.1.2 Sentence classification

• DQL( Data query language )： Query statement , be-all select sentence
• DML( Data operation language )：insert , delete , update , On the table data Conduct Additions and deletions
• DDL( Data definition language )：create , drop , alter Counter table structure Of Additions and deletions
• TCL( Transaction control language )：commit Submit data ,rollback Undo Data Transaction
• DCL( Data control language )：grant to grant authorization ,revoke Revocation of authority, etc

3.1.3 Basic statement

Check the library ：

• show databases;
• select schema_name from information_schema.schemata;

Building database ：

• create database + Library name ;

Delete library ：

• drop database + Library name ;

Access to database ：

• use + Library name ;

Look up the table ：

• show tables;
• select table_name from information_schema.tables where table_schema='securit
• select table_name from information_schema.tables where table_schema=database Basic functions

List ：

• select * from users;
• select column_name from information_schema.columns where table_name='users'

Check field ：

• select username,password from security.users;

 3.1.4  Basic functions

Database installation 、 route , user Information
version()	Mysql Database version
database()	Current database name
user()	The user name of the database
current_user()	Current user name
session_user()	The user name of the database connected to
system_user(）	System user name
@@datadir()	Storage path of database file
@@version_compile_os	Operating system version
@@basedir	Database installation directory

String length 、 Intercept
length()	Returns the length of the string
substring(a,b,c)	Intercepting string
substr(a,b,c)	Intercepting string
mid(a,b,c)	Intercepting string
Three parameters ：a. Intercepted string b. Intercept start position c. length
left(a,b)	Take... From the left a Before b position , Correct return 1, Erroneous return 0

Special handling of strings
ord()	return ASCII code
ascii('a')	Alphabet a Convert to ASCII value
rand()	return 0~1 Between random floating-point numbers
round()	Returns the latest integer value
md5()	return MD5 value
hex()	Converts a string to hexadecimal
unhex()	hex() Reverse operation of
floor(x)	Return is no greater than x Maximum integer for
load_file()	Read the file , Returns the contents of the file as a string
sleep(a)	A dead sleep a second
if(true,t,f)	The judgment sentence is true , Execute the first , Otherwise, the second
find_in_set()	Returns the position of the string in the string list
benchmark()	Specifies the number of times the statement is executed
name_const()	Return table as result

 3.1.5 Import data

  When you want to import a more Or you want to execute in batches sql When the sentence is , have access to mysql Medium source

Usage method ：source + File path ( Direct drag )