<-- Chapter 22: SQL Select Top

SQL Wildcard characters are used to substitute any characters in a string. As we have discussed LIKE operator in chapter 10. SQL supports two wildcard operators with LIKE operator i.e (%) and (_) underscore sign. The wildcards used in SQL are : -

• % : Zero or more characters can be substitute.
• _ : One character can be substitute.
• [charlist] : It sets and ranges of characters which are specified within the brackets to match in the table records.
• [!charlist] or [^charlist] : It matches only the characters which are not specified within the brackets to match in the table records.

Lets see an examples from the below table "employees" :-

% Wildcard SQL syntax :-

SELECT *
FROM `employees`
WHERE `designation` LIKE 'sof%'

Now run the above SQL query, we will see the output below :-

Now we can see here, those records are displayed which column designation values matched with the starting letters 'sof'.

_ Wildcard SQL syntax :-

SELECT * FROM `employees`
WHERE designation LIKE '_octor';

Now run the above SQL query, we will see the output below :-

Now we can see here, only those Records are displayed which column designation value starting with any character, followed by "octor".

[charlist] Wildcard SQL syntax :-

SELECT * FROM `employees`
WHERE `designation` LIKE '[edc]%';

Now run the above SQL query, we will see the output below :-

Now we can see here, only those Records are displayed which column designation value starting with "e", "d", or "c":

[!charlist] Wildcard SQL syntax :-

SELECT * FROM `employees`
WHERE `designation` LIKE '[!edc]%';

Now run the above SQL query, we will see the output below :-

Now we can see here, only those Records are displayed which column designation value does not starts with "e", "d", or "c":