72 lines
2.2 KiB
C
72 lines
2.2 KiB
C
/*
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* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
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*
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* This program is free software: you can use, redistribute, and/or modify
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* it under the terms of the GNU Affero General Public License, version 3
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* or later ("AGPL"), as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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// TAOS standard API example. The same syntax as MySQL, but only a subset
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// to compile: gcc -o with_reqid_demo with_reqid_demo.c -ltaos
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#include <inttypes.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "taosws.h"
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static int DemoWithReqId() {
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// ANCHOR: with_reqid
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int code = 0;
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char *dsn = "ws://localhost:6041";
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// connect
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WS_TAOS *taos = ws_connect(dsn);
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if (taos == NULL) {
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fprintf(stderr, "Failed to connect to %s, ErrCode: 0x%x, ErrMessage: %s.\n", dsn, ws_errno(NULL), ws_errstr(NULL));
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return -1;
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}
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const char *sql = "SELECT ts, current, location FROM power.meters limit 1";
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// query data with reqid
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long reqid = 3L;
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WS_RES *result = ws_query_with_reqid(taos, sql, reqid);
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code = ws_errno(result);
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if (code != 0) {
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fprintf(stderr, "Failed to execute sql withQID: %ld, ErrCode: 0x%x, ErrMessage: %s\n.", reqid, code,
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ws_errstr(result));
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ws_close(taos);
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return -1;
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}
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WS_ROW row = NULL;
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int rows = 0;
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int num_fields = ws_field_count(result);
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const WS_FIELD *fields = ws_fetch_fields(result);
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fprintf(stdout, "query successfully, got %d fields, the sql is: %s.\n", num_fields, sql);
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// fetch the records row by row
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while ((row = ws_fetch_row(result))) {
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// Add your data processing logic here
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rows++;
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}
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fprintf(stdout, "total rows: %d\n", rows);
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ws_free_result(result);
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// close & clean
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ws_close(taos);
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return 0;
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// ANCHOR_END: with_reqid
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}
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int main(int argc, char *argv[]) { return DemoWithReqId(); }
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