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/*
* Copyright (C) 2005-2016 Christoph Rupp (chris@crupp.de).
* All Rights Reserved.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* See the file COPYING for License information.
*/
/**
* This example demonstrates a few simple UQI queries.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h> /* for exit() */
#include <ups/upscaledb.h>
#include <ups/upscaledb_uqi.h>
#define DATABASE_NAME 1
void
error(const char *foo, ups_status_t st)
{
printf("%s() returned error %d: %s\n", foo, st, ups_strerror(st));
exit(-1);
}
int
main(int argc, char **argv)
{
ups_status_t st; /* status variable */
ups_env_t *env; /* upscaledb environment object */
ups_db_t *db; /* upscaledb database object */
ups_parameter_t params[] = { /* parameters for ups_env_create_db */
{UPS_PARAM_KEY_TYPE, UPS_TYPE_UINT32},
{UPS_PARAM_RECORD_TYPE, UPS_TYPE_UINT32},
{0, 0}
};
/* First create a new upscaledb Environment */
st = ups_env_create(&env, "test.db", 0, 0664, 0);
if (st != UPS_SUCCESS)
error("ups_env_create", st);
/* And in this Environment we create a new Database for uint32-keys
* and uint32-records. */
st = ups_env_create_db(env, &db, DATABASE_NAME, UPS_RECORD_NUMBER32,
&params[0]);
if (st != UPS_SUCCESS)
error("ups_env_create_db", st);
/*
* now insert a bunch of key/value pairs. The IDs are automatically
* assigned, the record is a pseudo-random value
*/
for (int i = 0; i < 10000; i++) {
uint32_t value = 50 + i % 30;
ups_key_t key = {0};
ups_record_t record = ups_make_record(&value, sizeof(value));
st = ups_db_insert(db, 0, &key, &record, 0);
if (st != UPS_SUCCESS)
error("ups_db_insert", st);
}
uqi_result_t *result;
ups_key_t key = {0};
ups_record_t record = {0};
/* now calculate the maximum record value */
st = uqi_select(env, "MAX($record) FROM DATABASE 1", &result);
if (st != UPS_SUCCESS)
error("uqi_select", st);
uqi_result_get_key(result, 0, &key);
uqi_result_get_record(result, 0, &record);
printf("MAX($record): key %2u, record %u\n",
*(uint32_t *)key.data, *(uint32_t *)record.data);
uqi_result_close(result);
/* ... and the minimum record value */
st = uqi_select(env, "MIN($record) FROM DATABASE 1", &result);
if (st != UPS_SUCCESS)
error("uqi_select", st);
uqi_result_get_key(result, 0, &key);
uqi_result_get_record(result, 0, &record);
printf("MIN($record): key %2u, record %u\n",
*(uint32_t *)key.data, *(uint32_t *)record.data);
uqi_result_close(result);
/* ... and the average record value */
st = uqi_select(env, "AVERAGE($record) FROM DATABASE 1", &result);
if (st != UPS_SUCCESS)
error("uqi_select", st);
uqi_result_get_record(result, 0, &record);
printf("AVERAGE($record): %f\n", *(double *)record.data);
uqi_result_close(result);
/* we're done! close the handles. UPS_AUTO_CLEANUP will also close the
* 'db' handle */
st = ups_env_close(env, UPS_AUTO_CLEANUP);
if (st != UPS_SUCCESS)
error("ups_env_close", st);
printf("success!\n");
return 0;
}