The SQL 
LIKE clause is used to compare a value to similar  values using wildcard operators. There are two wildcards used in  conjunction with the LIKE operator:
- The percent sign (%)
- The underscore (_)
The percent sign represents zero, one, or multiple characters. The  underscore represents a single number or character. The symbols can be  used in combinations.
Syntax:
The basic syntax of  %  and _ is as follows:
| SELECT FROM table_name
WHERE column LIKE 'XXXX%'
or 
SELECT FROM table_name
WHERE column LIKE '%XXXX%'
or
SELECT FROM table_name
WHERE column LIKE 'XXXX_'
or
SELECT FROM table_name
WHERE column LIKE '_XXXX'
or
SELECT FROM table_name
WHERE column LIKE '_XXXX_' | 
You can combine N number of conditions using AND or OR operators.  Here XXXX could be any numberic or string value.
Example:
Here are number of examples showing WHERE part having different LIKE  clause with '%' and '_' operators:
| Statement | Description | 
|---|
| WHERE SALARY LIKE '200%' | Finds any values that start  with 200 | 
| WHERE SALARY LIKE '%200%' | Finds any values that have 200  in any position | 
| WHERE SALARY LIKE '_00%' | Finds any values that have 00  in the second and third positions | 
| WHERE SALARY LIKE '2_%_%' | Finds any values that start  with 2 and are at least 3 characters in length | 
| WHERE SALARY LIKE '%2' | Finds any values that end with 2 | 
| WHERE SALARY LIKE '_2%3' | Finds any values that have a 2  in the second position and end with a 3 | 
| WHERE SALARY LIKE '2___3' | Finds any values in a  five-digit number that start with 2 and end with 3 | 
Let us take a real example, consider CUSTOMERS table is having  following records:
| +----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  2 | Khilan   |  25 | Delhi     |  1500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  4 | Chaitali |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  6 | Komal    |  22 | MP        |  4500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
+----+----------+-----+-----------+----------+ | 
Following is an example which would display all the records from  CUSTOMERS table where SALARY starts with 200:
| SQL> SELECT * FROM CUSTOMERS
WHERE SALARY LIKE '200%'; | 
This would produce following result:
+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
+----+----------+-----+-----------+----------+
 
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