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Diffstat (limited to 'src/third_party/wiredtiger/examples/c/ex_schema.c')
| -rw-r--r-- | src/third_party/wiredtiger/examples/c/ex_schema.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/examples/c/ex_schema.c b/src/third_party/wiredtiger/examples/c/ex_schema.c new file mode 100644 index 00000000000..fdf02d12302 --- /dev/null +++ b/src/third_party/wiredtiger/examples/c/ex_schema.c @@ -0,0 +1,364 @@ +/*- + * Public Domain 2014-2016 MongoDB, Inc. + * Public Domain 2008-2014 WiredTiger, Inc. + * + * This is free and unencumbered software released into the public domain. + * + * Anyone is free to copy, modify, publish, use, compile, sell, or + * distribute this software, either in source code form or as a compiled + * binary, for any purpose, commercial or non-commercial, and by any + * means. + * + * In jurisdictions that recognize copyright laws, the author or authors + * of this software dedicate any and all copyright interest in the + * software to the public domain. We make this dedication for the benefit + * of the public at large and to the detriment of our heirs and + * successors. We intend this dedication to be an overt act of + * relinquishment in perpetuity of all present and future rights to this + * software under copyright law. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * ex_schema.c + * This is an example application demonstrating how to create and access + * tables using a schema. + */ + +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <wiredtiger.h> + +static const char *home; + +/*! [schema declaration] */ +/* The C struct for the data we are storing in a WiredTiger table. */ +typedef struct { + char country[5]; + uint16_t year; + uint64_t population; +} POP_RECORD; + +static POP_RECORD pop_data[] = { + { "AU", 1900, 4000000 }, + { "AU", 1950, 8267337 }, + { "AU", 2000, 19053186 }, + { "CAN", 1900, 5500000 }, + { "CAN", 1950, 14011422 }, + { "CAN", 2000, 31099561 }, + { "UK", 1900, 369000000 }, + { "UK", 1950, 50127000 }, + { "UK", 2000, 59522468 }, + { "USA", 1900, 76212168 }, + { "USA", 1950, 150697361 }, + { "USA", 2000, 301279593 }, + { "", 0, 0 } +}; +/*! [schema declaration] */ + +int +main(void) +{ + POP_RECORD *p; + WT_CONNECTION *conn; + WT_CURSOR *cursor, *cursor2, *join_cursor; + WT_SESSION *session; + const char *country; + uint64_t recno, population; + uint16_t year; + int ret; + + /* + * Create a clean test directory for this run of the test program if the + * environment variable isn't already set (as is done by make check). + */ + if (getenv("WIREDTIGER_HOME") == NULL) { + home = "WT_HOME"; + ret = system("rm -rf WT_HOME && mkdir WT_HOME"); + } else + home = NULL; + + if ((ret = wiredtiger_open(home, NULL, "create", &conn)) != 0) { + fprintf(stderr, "Error connecting to %s: %s\n", + home, wiredtiger_strerror(ret)); + return (ret); + } + /* Note: error checking omitted for clarity. */ + + ret = conn->open_session(conn, NULL, NULL, &session); + + /*! [Create a table with column groups] */ + /* + * Create the population table. + * Keys are record numbers, the format for values is (5-byte string, + * uint16_t, uint64_t). + * See ::wiredtiger_struct_pack for details of the format strings. + */ + ret = session->create(session, "table:poptable", + "key_format=r," + "value_format=5sHQ," + "columns=(id,country,year,population)," + "colgroups=(main,population)"); + + /* + * Create two column groups: a primary column group with the country + * code, year and population (named "main"), and a population column + * group with the population by itself (named "population"). + */ + ret = session->create(session, + "colgroup:poptable:main", "columns=(country,year,population)"); + ret = session->create(session, + "colgroup:poptable:population", "columns=(population)"); + /*! [Create a table with column groups] */ + + /*! [Create an index] */ + /* Create an index with a simple key. */ + ret = session->create(session, + "index:poptable:country", "columns=(country)"); + /*! [Create an index] */ + + /*! [Create an index with a composite key] */ + /* Create an index with a composite key (country,year). */ + ret = session->create(session, + "index:poptable:country_plus_year", "columns=(country,year)"); + /*! [Create an index with a composite key] */ + + /*! [Create an immutable index] */ + /* Create an immutable index. */ + ret = session->create(session, + "index:poptable:immutable_year", "columns=(year),immutable"); + /*! [Create an immutable index] */ + + /* Insert the records into the table. */ + ret = session->open_cursor( + session, "table:poptable", NULL, "append", &cursor); + for (p = pop_data; p->year != 0; p++) { + cursor->set_value(cursor, p->country, p->year, p->population); + ret = cursor->insert(cursor); + } + ret = cursor->close(cursor); + + /* Update records in the table. */ + ret = session->open_cursor(session, + "table:poptable", NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_key(cursor, &recno); + ret = cursor->get_value(cursor, &country, &year, &population); + cursor->set_value(cursor, country, year, population + 1); + ret = cursor->update(cursor); + } + ret = cursor->close(cursor); + + /* List the records in the table. */ + ret = session->open_cursor(session, + "table:poptable", NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_key(cursor, &recno); + ret = cursor->get_value(cursor, &country, &year, &population); + printf("ID %" PRIu64, recno); + printf(": country %s, year %u, population %" PRIu64 "\n", + country, year, population); + } + ret = cursor->close(cursor); + + /*! [List the records in the table using raw mode.] */ + /* List the records in the table using raw mode. */ + ret = session->open_cursor(session, + "table:poptable", NULL, "raw", &cursor); + while ((ret = cursor->next(cursor)) == 0) { + WT_ITEM key, value; + + ret = cursor->get_key(cursor, &key); + ret = wiredtiger_struct_unpack(session, + key.data, key.size, "r", &recno); + printf("ID %" PRIu64, recno); + + ret = cursor->get_value(cursor, &value); + ret = wiredtiger_struct_unpack(session, + value.data, value.size, + "5sHQ", &country, &year, &population); + printf(": country %s, year %u, population %" PRIu64 "\n", + country, year, population); + } + /*! [List the records in the table using raw mode.] */ + ret = cursor->close(cursor); + + /*! [Read population from the primary column group] */ + /* + * Open a cursor on the main column group, and return the information + * for a particular country. + */ + ret = session->open_cursor( + session, "colgroup:poptable:main", NULL, NULL, &cursor); + cursor->set_key(cursor, 2); + if ((ret = cursor->search(cursor)) == 0) { + ret = cursor->get_value(cursor, &country, &year, &population); + printf("ID 2: country %s, year %u, population %" PRIu64 "\n", + country, year, population); + } + /*! [Read population from the primary column group] */ + ret = cursor->close(cursor); + + /*! [Read population from the standalone column group] */ + /* + * Open a cursor on the population column group, and return the + * population of a particular country. + */ + ret = session->open_cursor(session, + "colgroup:poptable:population", NULL, NULL, &cursor); + cursor->set_key(cursor, 2); + if ((ret = cursor->search(cursor)) == 0) { + ret = cursor->get_value(cursor, &population); + printf("ID 2: population %" PRIu64 "\n", population); + } + /*! [Read population from the standalone column group] */ + ret = cursor->close(cursor); + + /*! [Search in a simple index] */ + /* Search in a simple index. */ + ret = session->open_cursor(session, + "index:poptable:country", NULL, NULL, &cursor); + cursor->set_key(cursor, "AU\0\0\0"); + ret = cursor->search(cursor); + ret = cursor->get_value(cursor, &country, &year, &population); + printf("AU: country %s, year %u, population %" PRIu64 "\n", + country, (unsigned int)year, population); + /*! [Search in a simple index] */ + ret = cursor->close(cursor); + + /*! [Search in a composite index] */ + /* Search in a composite index. */ + ret = session->open_cursor(session, + "index:poptable:country_plus_year", NULL, NULL, &cursor); + cursor->set_key(cursor, "USA\0\0", (uint16_t)1900); + ret = cursor->search(cursor); + ret = cursor->get_value(cursor, &country, &year, &population); + printf("US 1900: country %s, year %u, population %" PRIu64 "\n", + country, (unsigned int)year, population); + /*! [Search in a composite index] */ + ret = cursor->close(cursor); + + /*! [Return a subset of values from the table] */ + /* + * Use a projection to return just the table's country and year + * columns. + */ + ret = session->open_cursor(session, + "table:poptable(country,year)", NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_value(cursor, &country, &year); + printf("country %s, year %u\n", country, year); + } + /*! [Return a subset of values from the table] */ + ret = cursor->close(cursor); + + /*! [Return a subset of values from the table using raw mode] */ + /* + * Use a projection to return just the table's country and year + * columns, using raw mode. + */ + ret = session->open_cursor(session, + "table:poptable(country,year)", NULL, "raw", &cursor); + while ((ret = cursor->next(cursor)) == 0) { + WT_ITEM value; + + ret = cursor->get_value(cursor, &value); + ret = wiredtiger_struct_unpack( + session, value.data, value.size, "5sH", &country, &year); + printf("country %s, year %u\n", country, year); + } + /*! [Return a subset of values from the table using raw mode] */ + ret = cursor->close(cursor); + + /*! [Return the table's record number key using an index] */ + /* + * Use a projection to return just the table's record number key + * from an index. + */ + ret = session->open_cursor(session, + "index:poptable:country_plus_year(id)", NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_key(cursor, &country, &year); + ret = cursor->get_value(cursor, &recno); + printf("row ID %" PRIu64 ": country %s, year %u\n", + recno, country, year); + } + /*! [Return the table's record number key using an index] */ + ret = cursor->close(cursor); + + /*! [Return a subset of the value columns from an index] */ + /* + * Use a projection to return just the population column from an + * index. + */ + ret = session->open_cursor(session, + "index:poptable:country_plus_year(population)", + NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_key(cursor, &country, &year); + ret = cursor->get_value(cursor, &population); + printf("population %" PRIu64 ": country %s, year %u\n", + population, country, year); + } + /*! [Return a subset of the value columns from an index] */ + ret = cursor->close(cursor); + + /*! [Access only the index] */ + /* + * Use a projection to avoid accessing any other column groups when + * using an index: supply an empty list of value columns. + */ + ret = session->open_cursor(session, + "index:poptable:country_plus_year()", NULL, NULL, &cursor); + while ((ret = cursor->next(cursor)) == 0) { + ret = cursor->get_key(cursor, &country, &year); + printf("country %s, year %u\n", country, year); + } + /*! [Access only the index] */ + ret = cursor->close(cursor); + + /*! [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, + "index:poptable:country", NULL, NULL, &cursor); + ret = session->open_cursor(session, + "index:poptable:immutable_year", NULL, NULL, &cursor2); + + /* 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, + "compare=eq,count=10"); + cursor2->set_key(cursor2, (uint16_t)1900); + ret = cursor2->search(cursor2); + ret = session->join(session, join_cursor, cursor2, + "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 %u, population %" PRIu64 "\n", + country, year, population); + } + /*! [Join cursors] */ + ret = join_cursor->close(join_cursor); + ret = cursor2->close(cursor2); + ret = cursor->close(cursor); + + ret = conn->close(conn, NULL); + + return (ret); +} |