ALLTRIM( ) function
Returns a new string containing a copy of the specified string with leading and trailing spaces removed.
This function removes the leading and trailing spaces from a string. Spaces inside the string are not removed. You can use this function when you are concatenating character values, such as first name and last name fields, and you want to eliminate blanks so that the resulting field does not contain large blank spaces between the names.
LTRIM( ) function
Use this if you only want to remove leading spaces from a string.
TRIM( ) function
Use this if you only want to remove trailing spaces.