94 lines
2.5 KiB
JavaScript
94 lines
2.5 KiB
JavaScript
/* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved. */
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/******************************************************************************
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*
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* You may not use the identified files except in compliance with the Apache
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* License, Version 2.0 (the "License.")
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*
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* You may obtain a copy of the License at
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* http://www.apache.org/licenses/LICENSE-2.0.
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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*
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* NAME
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* selectstream.js
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*
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* DESCRIPTION
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* Executes a basic query using a Readable Stream.
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* Uses Oracle's sample HR schema.
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*
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* Scripts to create the HR schema can be found at:
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* https://github.com/oracle/db-sample-schemas
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*
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* This example requires node-oracledb 1.8 or later.
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*
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* This example uses Node 8's async/await syntax.
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*
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*****************************************************************************/
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const oracledb = require('oracledb');
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const dbConfig = require('./dbconfig.js');
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async function run() {
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let connection;
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try {
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connection = await oracledb.getConnection(dbConfig);
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const stream = await connection.queryStream(
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`SELECT first_name, last_name
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FROM employees
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ORDER BY employee_id`,
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[], // no binds
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{
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fetchArraySize: 150 // internal buffer size used for performance tuning
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}
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);
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const consumeStream = new Promise((resolve, reject) => {
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let rowcount = 0;
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stream.on('error', function(error) {
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// console.log("stream 'error' event");
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reject(error);
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});
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stream.on('metadata', function(metadata) {
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// console.log("stream 'metadata' event");
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console.log(metadata);
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});
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stream.on('data', function(data) {
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// console.log("stream 'data' event");
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console.log(data);
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rowcount++;
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});
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stream.on('end', function() {
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// console.log("stream 'end' event");
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resolve(rowcount);
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});
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});
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const numrows = await consumeStream;
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console.log('Rows selected: ' + numrows);
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} catch (err) {
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console.error(err);
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} finally {
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if (connection) {
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try {
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await connection.close();
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} catch (err) {
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console.error(err);
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}
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}
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}
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}
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run();
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