node-oracledb/examples/resultset1.js

101 lines
3.1 KiB
JavaScript

/* Copyright (c) 2015, 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
* resultset1.js
*
* DESCRIPTION
* Executes a query and uses a ResultSet to fetch rows with getRow().
* Uses Oracle's sample HR schema.
*
* Note using queryStream() or getRows() is recommended instead of
* getRow().
*
*****************************************************************************/
var oracledb = require('oracledb');
var dbConfig = require('./dbconfig.js');
// For getRow(), the fetchArraySize property can be adjusted to tune
// data transfer from the Oracle Database to node-oracledb. The value
// of fetchArraySize does not affect how, or when, rows are returned
// by node-oracledb to the application. Buffering is handled by
// node-oracledb. Benchmark to choose the optimal size for each
// application or query.
//
// oracledb.fetchArraySize = 100; // default value is 100
var rowCount = 0;
oracledb.getConnection(
{
user : dbConfig.user,
password : dbConfig.password,
connectString : dbConfig.connectString
},
function(err, connection) {
if (err) { console.error(err.message); return; }
connection.execute(
`SELECT employee_id, last_name
FROM employees
WHERE ROWNUM < 11
ORDER BY employee_id`,
[], // no bind variables
{ resultSet: true }, // return a ResultSet. Default is false
function(err, result) {
if (err) {
console.error(err.message);
doRelease(connection);
return;
}
// console.log(result);
fetchOneRowFromRS(connection, result.resultSet);
});
});
function fetchOneRowFromRS(connection, resultSet) {
resultSet.getRow( // get one row
function (err, row) {
if (err) {
console.error(err.message);
doClose(connection, resultSet); // always close the ResultSet
} else if (!row) { // no rows, or no more rows
doClose(connection, resultSet); // always close the ResultSet
} else {
rowCount++;
console.log("fetchOneRowFromRS(): row " + rowCount);
console.log(row);
fetchOneRowFromRS(connection, resultSet);
}
});
}
function doRelease(connection) {
connection.close(
function(err) {
if (err) { console.error(err.message); }
});
}
function doClose(connection, resultSet) {
resultSet.close(
function(err) {
if (err) { console.error(err.message); }
doRelease(connection);
});
}