SQL wildcards can substitute for one or more characters when searching for data in a database. SQL wildcards must be used with the SQL LIKE operator which is used to compare a value to similar values using wildcard operators.
Two wildcard Operators in SQL are as under:
1) The percent sign (%): It matches one or more characters. Note that MS Access uses the asterisk (*) wildcard character instead of the percent sign (%) wildcard character.
SELECT * FROM table_name
WHERE column LIKE 'ABC%'
2) The underscore (_): It matches one character. Note that MS Access uses a question mark (?) instead of the underscore (_) to match any one character.
SELECT * FROM table_name WHERE column LIKE '_ABC'
The percent sign represents zero, one, or multiple characters and the underscore represents a single number or character. The symbols can be used in combinations.