This wildcards is used when we want to match a string pattern . And this can be do with the help of wildcards only .
In SQL there are two types of wildcards :
% : Percentage sign which represent 0 , 1 or more characters .
_ : Underscore which represent exactly one character .
Example :
Table name : Employee_Info

  Id        Employee_name          Employee_Age         Employee _Salary     City 
  1            Mukesh                  23                  120000            Meerut
  2            Ayush                   24                  200000            Baroda
  3            Ishan                   40                  400000            Multan
  4            Pranav                  35                  123,00000         Dehradun
  5            Abhishek                26                  800000            Mussoorie
  6            Ravi                    25                  300000           Pauri-Garhwal
  7            David                   40                  8000              Baghpat

Query : To select city where city start with M

select * from Employee_Info where City like ' M% ' ;

Output : All recods will come in which city is starting from letter M .

Id        Employee_name          Employee_Age         Employee _Salary      City
1            Mukesh                  23                  120000            Meerut
3            Ishan                   40                  400000            Multan
5            Abhishek                26                  800000            Mussoorie

Query :

select * from Employee_Info where City like ' %n ' ;

Output : All recods will come in which city is ending with letter n .

Id        Employee_name          Employee_Age         Employee _Salary      City
 3            Ishan                   40                  400000            Multan
 4            Pranav                  35                  123,00000         Dehradun

Query :

select * from Employee_Info where City like ' %ss% ' ;

Output : All recods will come in which city containing the pattern " ss " .

Id        Employee_name          Employee_Age         Employee _Salary      City
5            Abhishek                26                  800000            Mussoorie

Query : To select a city starting with any character followed by " tan "

select * from Employee_Info where City like ' _tan ' ;

Output : All recods will come in which city containing the pattern " tan " .

Id        Employee_name          Employee_Age         Employee _Salary      City
3            Ishan                   40                  400000            Multan

Query : To select a city starting with " M " followed by any character followed by " er " followed by any character followed by " ut "

select * from Employee_Info where City like 'M _er_ut ' ;

*Output : *

Id        Employee_name          Employee_Age         Employee _Salary      City
 1            Mukesh                  23                  120000            Meerut

Query : To select a city starting with " M " , " B "

select * from Employee_Info where City like ' [MB]% ' ;

*Output : *

Id        Employee_name          Employee_Age         Employee _Salary      City
1            Mukesh                  23                  120000            Meerut
3            Ishan                   40                  400000            Multan
5            Abhishek                26                  800000            Mussoorie
7            David                   40                  8000              Baghpat