The trim_spec clause is used to specify that spaces should be trimmed from the beginning of a text field, the end of a text field, or both. Spaces include blanks and other nonprinting characters such as tabs, line feeds, and carriage returns. The syntax for the trim_spec clause is as follows:

NOTRIM indicates that no characters will be trimmed from the field.

LRTRIM, LTRIM, and RTRIM are used to indicate that characters should be trimmed from the field. LRTRIM means that both leading and trailing spaces are trimmed. LTRIM means that leading spaces will be trimmed. RTRIM means trailing spaces are trimmed.

LDRTRIM is used to provide compatibility with SQL*Loader trim features. It is the same as NOTRIM except in the following cases:

  • If the field is not a delimited field, then spaces will be trimmed from the right.

  • If the field is a delimited field with OPTIONALLY ENCLOSED BY specified, and the optional enclosures are missing for a particular instance, then spaces will be trimmed from the left.

The default is LDRTRIM. Specifying NOTRIM yields the fastest performance.

The trim_spec clause can be specified before the field list to set the default trimming for all fields. If trim_spec is omitted before the field list, then LDRTRIM is the default trim setting. The default trimming can be overridden for an individual field as part of the datatype_spec.

If trimming is specified for a field that is all spaces, then the field will be set to NULL.

In the following example, all data is fixed-length; however, the character data will not be loaded with leading spaces. The example is followed by a sample of the data file that can be used to load it.

CREATE TABLE emp_load (first_name CHAR(15), last_name CHAR(20),
year_of_birth CHAR(4))
                         ACCESS PARAMETERS (FIELDS LTRIM)
                         LOCATION ('info.dat'));

Alvin,           Tolliver,1976
Kenneth,         Baer,    1963
Mary,            Dube,    1973