When would I use "%d" versus "%d%"?

The use of %d and %d% is related to the LIKE operator, which is used to search for a specified pattern in a column. The % character is a wildcard that can represent any sequence of characters (including no characters at all). Here's how they work:

%d: This pattern is used to find values that end with the letter 'd'. For example,

SELECT * FROM table WHERE column LIKE '%d';

This will return all rows where the column ends with the letter 'd'. For example, it would match "keyboard", "mousepad", and "sand".

%d%: This pattern is used to find values that contain the letter 'd' anywhere in the string. For example,

SELECT * FROM table WHERE column LIKE '%d%';

This will return all rows where the column contains the letter 'd' at any position in the string. For example, it would match "ride", "window", and "card".