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//-----------------------------------------------------------------------------
// Copyright (c) 2016, 2022, Oracle and/or its affiliates.
//
// This software is dual-licensed to you under the Universal Permissive License
// (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
// 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose
// either license.
//
// If you elect to accept the software under the Apache License, Version 2.0,
// the following applies:
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// DemoCQN.c
// Demos continuous query notification.
//-----------------------------------------------------------------------------
#ifdef _WIN32
#include <windows.h>
#define sleep(seconds) Sleep(seconds * 1000)
#else
#include <unistd.h>
#endif
#include "SampleLib.h"
#define SQL_TEXT "select * from DemoTempTable"
//-----------------------------------------------------------------------------
// DemoCallback()
// Demo callback for continuous query notification.
//-----------------------------------------------------------------------------
void DemoCallback(void *context, dpiSubscrMessage *message)
{
dpiSubscrMessageQuery *query;
dpiSubscrMessageTable *table;
dpiSubscrMessageRow *row;
uint32_t i, j, k;
// check for error
if (message->errorInfo) {
fprintf(stderr, "ERROR: %.*s (%s: %s)\n",
message->errorInfo->messageLength, message->errorInfo->message,
message->errorInfo->fnName, message->errorInfo->action);
return;
}
// display contents of message
printf("===========================================================\n");
printf("NOTIFICATION RECEIVED from database %.*s (EVENT TYPE %d)\n",
message->dbNameLength, message->dbName, message->eventType);
printf("===========================================================\n");
for (i = 0; i < message->numQueries; i++) {
query = &message->queries[i];
printf("--> Query ID: %" PRIu64 "\n", query->id);
for (j = 0; j < query->numTables; j++) {
table = &query->tables[j];
printf("--> --> Table Name: %.*s\n", table->nameLength,
table->name);
printf("--> --> Table Operation: %d\n", table->operation);
if (table->numRows > 0) {
printf("--> --> Table Rows:\n");
for (k = 0; k < table->numRows; k++) {
row = &table->rows[k];
printf("--> --> --> ROWID: %.*s\n", row->rowidLength,
row->rowid);
printf("--> --> --> Operation: %d\n", row->operation);
}
}
}
}
}
//-----------------------------------------------------------------------------
// main()
//-----------------------------------------------------------------------------
int main(int argc, char **argv)
{
dpiCommonCreateParams commonParams;
dpiSubscrCreateParams createParams;
uint32_t numQueryColumns, i;
dpiSampleParams *params;
dpiSubscr *subscr;
uint64_t queryId;
dpiStmt *stmt;
dpiConn *conn;
// connect to database
// NOTE: events mode must be configured
params = dpiSamples_getParams();
if (dpiContext_initCommonCreateParams(params->context, &commonParams) < 0)
return dpiSamples_showError();
commonParams.createMode = DPI_MODE_CREATE_EVENTS;
conn = dpiSamples_getConn(0, &commonParams);
// create subscription
if (dpiContext_initSubscrCreateParams(params->context, &createParams) < 0)
return dpiSamples_showError();
createParams.qos = DPI_SUBSCR_QOS_QUERY | DPI_SUBSCR_QOS_ROWIDS;
createParams.callback = DemoCallback;
if (dpiConn_subscribe(conn, &createParams, &subscr) < 0)
return dpiSamples_showError();
printf("Created subscription with registration id %" PRIu64 "\n",
createParams.outRegId);
// register query
if (dpiSubscr_prepareStmt(subscr, SQL_TEXT, strlen(SQL_TEXT), &stmt) < 0)
return dpiSamples_showError();
if (dpiStmt_execute(stmt, DPI_MODE_EXEC_DEFAULT, &numQueryColumns) < 0)
return dpiSamples_showError();
if (dpiStmt_getSubscrQueryId(stmt, &queryId) < 0)
return dpiSamples_showError();
dpiStmt_release(stmt);
printf("Registered query with id %" PRIu64 "\n\n", queryId);
// wait for events to come through
printf("In another session, modify the results of the query\n\n%s\n\n",
SQL_TEXT);
printf("Use Ctrl-C to terminate or wait for 100 seconds\n");
for (i = 0; i < 20; i++) {
printf("Waiting for notifications...\n");
sleep(5);
}
// clean up
dpiSubscr_release(subscr);
dpiConn_release(conn);
printf("Done.\n");
return 0;
}
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