The first three passes of sqli Labs

The first level

Then we decide whether the assignment is character type or number type id=1 And id=2-1
Find the difference, so this is a character type

Then we judge the injection mode input id=1’
Display error
We use it id=1‘order x–+ To confirm the number of fields
x=4 Times wrong
So the number of fields is 3
We query the database for information and users

Look up the table

Find field information

Check the account number and password

The second level

It is the same as the first level. First, judge whether it is character type or number type
assignment id=1 And id=2-1
It is found that they are the same, so it is judged as digital type
Follow the first step to get

The third level

We input id=2’ Find back

Analysis what we input is 2‘ And back to “2”）LIMIT 0,1’
So guess this is （‘id’） Closed
We use order by 3–+ After sorting, she found that she had three sets of data （ If it exceeds three, an error will be reported ）
We then query the database name and data users

Then the user name and password will be solved step by step like the first level