node-oracledb/examples/resultsettoquerystream.js

78 lines
2.3 KiB
JavaScript

/* Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved. */
/******************************************************************************
*
* You may not use the identified files except in compliance with the Apache
* License, Version 2.0 (the "License.")
*
* You may obtain a copy of the License at
* http://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.
*
* NAME
* resultsettoquerystream.js
*
* DESCRIPTION
* Converts a ResultSet returned from execute() into a Readable Stream.
* This is an alternative instead of using resultset.getRows().
* Note: using connection.queryStream() is recommended for top level
* queries because it avoids having to duplicate error handling in the
* callback and event.
*
* Scripts to create the HR schema can be found at:
* https://github.com/oracle/db-sample-schemas
*
*****************************************************************************/
var oracledb = require('oracledb');
var dbConfig = require('./dbconfig.js');
oracledb.getConnection(
dbConfig,
function(err, connection) {
if (err) { console.error(err.message); return; }
var sql = "SELECT employee_id, last_name FROM employees WHERE ROWNUM < 25 ORDER BY employee_id";
connection.execute(
sql,
[],
{
resultSet: true
},
function(err, result) {
if (err) {
console.error(err.message);
doRelease(connection);
return;
}
var queryStream = result.resultSet.toQueryStream();
queryStream.on('data', function(row) {
console.log(row);
});
queryStream.on('error', function(err) {
console.error(err.message);
doRelease(connection);
});
queryStream.on('close', function() {
doRelease(connection);
});
}
);
}
);
function doRelease(connection) {
connection.close(
function(err) {
if (err) { console.error(err.message); }
});
}