SQL blind study - time type

  The time to learn to type blind, or use sqli-labs environment.

  First, look at the time-of-blinds need to use:

  1, if () function if (a, b, c)

  If a true executing b, or perform c. As shown in FIG, 1 = 1 is true since it executes the second parameter 2;

   

 

  When the result is 11 = 1 is false, the implementation of the third parameter 3;

 

 

 

  2, sleep () sleep function can make this statement runs N seconds

  

 

  We can see that this code is executed 5 seconds

  The next query 1 = 1 if true, then perform 1, is false is executed 5 seconds;

 

  1 = 1 is true because it is a query is executed with a time of 0 seconds, almost imperceptible delay; 1 = 2, the third field is performed results, query 5 seconds, can feel a significant delay.

 

 

 

  Next, using the sleep () function to determine whether the first letter of the current database sqli-labs returns 1 (due echoed the same page so the page will be prompted You are in ......) is a, is true, false then execute the query 5 seconds 

  http://localhost:8088/sqli-labs/Less-5/?id=1' and if(substr((select database()),1,1)='a',1,sleep(5)) --+

 

 

  Page feel significantly delayed 5 seconds after the page appears to be empty; keep trying until the query page is displayed without delay You are in ......, to find the right character s,

 

 

  Later step are relatively similar, it will not be repeated.

 

 

 

 

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Origin www.cnblogs.com/hai-long/p/11883002.html