Here are my learnings:
- upper and lower functions does not return an error when used with null data.
- The second argument for left and right functions should be a positive value and cannot be a negative value.
- If a negative value is used the select statement errors out.
- If a zero is used as the second argument it does not return an error but it just returns a blank row.
- There is no trim functions. If you need a trim function in sql then combine the ltrim and rtrim functions to get the desired result. Eg: rtrim(ltrim(@test))