Most SQL queries return only a single result set - a list of rows. However, some queries can return more than one result set. For example,’SELECT 1; SELECT 2' is a batch query that returns a single row (1) and then a single row(2). Queries involving stored procedures can easily generate such results.
To retrieve data from a subsequent result set, odbc_next_result_set/1 can be used, but only for prepared queries which were prepared with fetch(fetch) as the fetch style in the option list.
- Succeeds if there is another result set, and positions the cursor at the
first row of the new result set. If there are no more result sets, the
fetch(Options) :- odbc_prepare(test, 'select (testval) from test; select (anotherval) from some_other_table', , Statement, [ fetch(fetch) ]), odbc_execute(Statement, ), fetch(Statement, Options). fetch(Statement, Options) :- odbc_fetch(Statement, Row, Options), ( Row == end_of_file -> ( odbc_next_result_set(Statement) -> writeln(next_result_set), fetch(Statement, Options) ; true ) ; writeln(Row), fetch(Statement, Options) ).