How to Check if value exists in a MySQL database

Question

Suppose I have this table:

id | name | city
------------------
1  | n1   | c1
2  | n2   | c2
3  | n3   | c3
4  | n4   | c4

I want to check

Answer 1

For Matching the ID:

Select * from table_name where 1=1

For Matching the Pattern:

Select * from table_name column_name Like '%string%'