node-oracledb/examples/resultset2.js

97 lines
2.9 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
* resultset2.js
*
* DESCRIPTION
* Executes a query and uses a ResultSet to fetch batches of rows
* with getRows(). Also shows setting the fetch array size.
* Uses Oracle's sample HR schema.
*
*****************************************************************************/
var oracledb = require('oracledb');
var dbConfig = require('./dbconfig.js');
// Number of rows to return from each call to getRows()
var numRows = 10;
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 < 25
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);
fetchRowsFromRS(connection, result.resultSet, numRows);
});
});
function fetchRowsFromRS(connection, resultSet, numRows) {
resultSet.getRows(
numRows, // get this many rows
function (err, rows) {
if (err) {
console.error(err);
doClose(connection, resultSet); // always close the ResultSet
} else if (rows.length > 0) {
console.log("fetchRowsFromRS(): Got " + rows.length + " rows");
console.log(rows);
if (rows.length === numRows) // might be more rows
fetchRowsFromRS(connection, resultSet, numRows);
else
doClose(connection, resultSet); // always close the ResultSet
} else { // no rows
doClose(connection, resultSet); // always close the 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);
});
}