Answer

In SQL queries, the wildcard used to represent zero or more characters is the percent sign (%).

Wildcards are special characters that can be used in SQL with the LIKE operator to search for specific patterns in a column. The percent sign (%) can replace any number of characters, including zero characters, making it very versatile in matching strings.

For instance, if you want to find all records in a table where a certain column’s value starts with "A" and can be followed by any combination of characters, you would use the pattern A%. This would match "Apple", "A1B2C3", or even just "A" itself, since the percent sign allows for zero or more characters to follow it.

In contrast, the underscore (_) wildcard is used to represent a single character, which is another common wildcard in SQL queries.

To summarize, when needing to include a portion of a string while accounting for any additional characters, use %.