For example, use the following clause to load a blank field as null:
full_fieldname ... NULLIF column_name=BLANKS
BLANKS parameter recognizes only blanks, not tabs. It can be used in place of a literal string in any field comparison. The condition is true whenever the column is entirely blank.
BLANKS parameter also works for fixed-length fields. Using it is the same as specifying an appropriately sized literal string of blanks. For example, the following specifications are equivalent:
fixed_field CHAR(2) NULLIF fixed_field=BLANKS fixed_field CHAR(2) NULLIF fixed_field=" "
There can be more than one blank in a multibyte character set. It is a good idea to use the
BLANKS parameter with these character sets instead of specifying a string of blank characters.
The character string will match only a specific sequence of blank characters, while the
BLANKS parameter will match combinations of different blank characters. For more information about multibyte character sets, see "Multibyte (Asian) Character Sets".