What symbol is used with the LIKE clause and represents zero, one or multiple characters?
The correct answer and explanation is:
Correct Answer: % (percent sign)
The % symbol is used in SQL with the LIKE clause to represent zero, one, or multiple characters in a string pattern. It acts as a wildcard that helps filter results based on partial matching rather than exact values.
The LIKE clause is commonly used in SELECT statements to search for a specified pattern in a column. For example, if you want to find all names that start with the letter “A,” you could use the query:
SELECT * FROM customers WHERE name LIKE 'A%';
In this case, the % symbol allows the database to return all names that begin with “A” and are followed by any number of characters, including none. So it would match “Alex,” “Andrew,” and even just “A” if such a record exists.
Similarly, if you want to find names that end with “son,” you could use:
SELECT * FROM customers WHERE name LIKE '%son';
This would match entries such as “Johnson,” “Emerson,” or “Mason.”
You can also place % on both sides to find values that contain a certain substring anywhere within the text. For example:
SELECT * FROM customers WHERE name LIKE '%ann%';
This will return names such as “Annette,” “Joanna,” or “Hannah.”
The flexibility of the % wildcard makes it useful for pattern matching in text-based data. It simplifies searching large databases without needing the exact text. For more specific matches, the underscore _ can be used to represent exactly one character, whereas % is open-ended, allowing for any number of characters.