There are two predicates for reading records. The read_table_record/4
reads an entire record, while read_table_fields/4
reads one or more fields from a record.
- read_table_record(+Handle,
+Start, -Next, -Record)
- Read a record from the table. Handle is a handle as returned
by new_table/4. Start
is the location of a record. If Start does not point to the
start of a record, this predicate searches backwards for the starting
position. Record is unified with a term constructed from the functor
associated with the table (default name
record and arity
the number of not-skipped columns), each of the arguments containing the
converted data. An error is raised if the data could not be converted. Next
is unified with the start position for the next record.
- read_table_fields(+Handle,
+Start, -Next, -Fields)
- As read_table_record/4,
but Fields is a list of terms
+Name(-Value), and the Values will be
unified with the values of the specified field.
- read_table_record_data(+Handle,
+Start, -Next, -Record)
- Similar to read_table_record/4,
but unifies record with a Prolog string containing the data of the
record unparsed. The returned record does not contain the
terminating record-separator.