diff options
Diffstat (limited to 'examples/c/ex_schema.c')
| -rw-r--r-- | examples/c/ex_schema.c | 76 |
1 files changed, 65 insertions, 11 deletions
diff --git a/examples/c/ex_schema.c b/examples/c/ex_schema.c index 70fc7eb2e62..155b982bbbe 100644 --- a/examples/c/ex_schema.c +++ b/examples/c/ex_schema.c @@ -69,7 +69,8 @@ main(void) { POP_RECORD *p; WT_CONNECTION *conn; - WT_CURSOR *cursor, *cursor2, *join_cursor, *stat_cursor; + WT_CURSOR *country_cursor, *country_cursor2, *cursor, *join_cursor, + *stat_cursor, *subjoin_cursor, *year_cursor; WT_SESSION *session; const char *country; uint64_t recno, population; @@ -336,18 +337,18 @@ main(void) ret = session->open_cursor(session, "join:table:poptable", NULL, NULL, &join_cursor); ret = session->open_cursor(session, - "index:poptable:country", NULL, NULL, &cursor); + "index:poptable:country", NULL, NULL, &country_cursor); ret = session->open_cursor(session, - "index:poptable:immutable_year", NULL, NULL, &cursor2); + "index:poptable:immutable_year", NULL, NULL, &year_cursor); /* select values WHERE country == "AU" AND year > 1900 */ - cursor->set_key(cursor, "AU\0\0\0"); - ret = cursor->search(cursor); - ret = session->join(session, join_cursor, cursor, + country_cursor->set_key(country_cursor, "AU\0\0\0"); + ret = country_cursor->search(country_cursor); + ret = session->join(session, join_cursor, country_cursor, "compare=eq,count=10"); - cursor2->set_key(cursor2, (uint16_t)1900); - ret = cursor2->search(cursor2); - ret = session->join(session, join_cursor, cursor2, + year_cursor->set_key(year_cursor, (uint16_t)1900); + ret = year_cursor->search(year_cursor); + ret = session->join(session, join_cursor, year_cursor, "compare=gt,count=10,strategy=bloom"); /* List the values that are joined */ @@ -370,8 +371,61 @@ main(void) ret = stat_cursor->close(stat_cursor); ret = join_cursor->close(join_cursor); - ret = cursor2->close(cursor2); - ret = cursor->close(cursor); + ret = year_cursor->close(year_cursor); + ret = country_cursor->close(country_cursor); + + /*! [Complex join cursors] */ + /* Open cursors needed by the join. */ + ret = session->open_cursor(session, + "join:table:poptable", NULL, NULL, &join_cursor); + ret = session->open_cursor(session, + "join:table:poptable", NULL, NULL, &subjoin_cursor); + ret = session->open_cursor(session, + "index:poptable:country", NULL, NULL, &country_cursor); + ret = session->open_cursor(session, + "index:poptable:country", NULL, NULL, &country_cursor2); + ret = session->open_cursor(session, + "index:poptable:immutable_year", NULL, NULL, &year_cursor); + + /* + * select values WHERE (country == "AU" OR country == "UK") + * AND year > 1900 + * + * First, set up the join representing the country clause. + */ + country_cursor->set_key(country_cursor, "AU\0\0\0"); + ret = country_cursor->search(country_cursor); + ret = session->join(session, subjoin_cursor, country_cursor, + "operation=or,compare=eq,count=10"); + country_cursor2->set_key(country_cursor2, "UK\0\0\0"); + ret = country_cursor2->search(country_cursor2); + ret = session->join(session, subjoin_cursor, country_cursor2, + "operation=or,compare=eq,count=10"); + + /* Join that to the top join, and add the year clause */ + ret = session->join(session, join_cursor, subjoin_cursor, NULL); + year_cursor->set_key(year_cursor, (uint16_t)1900); + ret = year_cursor->search(year_cursor); + ret = session->join(session, join_cursor, year_cursor, + "compare=gt,count=10,strategy=bloom"); + + /* List the values that are joined */ + while ((ret = join_cursor->next(join_cursor)) == 0) { + ret = join_cursor->get_key(join_cursor, &recno); + ret = join_cursor->get_value(join_cursor, &country, &year, + &population); + printf("ID %" PRIu64, recno); + printf( + ": country %s, year %" PRIu16 ", population %" PRIu64 "\n", + country, year, population); + } + /*! [Complex join cursors] */ + + ret = join_cursor->close(join_cursor); + ret = subjoin_cursor->close(subjoin_cursor); + ret = country_cursor->close(country_cursor); + ret = country_cursor2->close(country_cursor2); + ret = year_cursor->close(year_cursor); ret = conn->close(conn, NULL); |