node-oracledb/examples/lobinsert2.js

123 lines
3.3 KiB
JavaScript

/* Copyright (c) 2015, 2019, 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
* lobinsert2.js
*
* DESCRIPTION
* INSERTs text into a CLOB column using the 'RETURNING INTO' method.
*
* For smaller LOBs you will probably prefer the method shown in lobinsert1.js
*
* Create clobexample.txt before running this example.
* Use demo.sql to create the required table or do:
* DROP TABLE mylobs;
* CREATE TABLE mylobs (id NUMBER, c CLOB, b BLOB);
*
* This example requires node-oracledb 1.12 or later.
*
*****************************************************************************/
var fs = require('fs');
var oracledb = require('oracledb');
var dbConfig = require('./dbconfig.js');
var inFileName = 'clobexample.txt'; // the file with text to be inserted into the database
async function run() {
let connection;
try {
const connection = await oracledb.getConnection(dbConfig);
const result = await connection.execute(
`INSERT INTO mylobs (id, c) VALUES (:id, EMPTY_CLOB()) RETURNING c INTO :lobbv`,
{
id: 4,
lobbv: {type: oracledb.CLOB, dir: oracledb.BIND_OUT}
},
{ autoCommit: false } // a transaction needs to span the INSERT and pipe()
);
if (result.rowsAffected != 1 || result.outBinds.lobbv.length != 1) {
throw new Error('Error getting a LOB locator');
}
const lob = result.outBinds.lobbv[0];
if (lob === null) {
throw new Error('NULL lob found');
}
const doStream = new Promise((resolve, reject) => {
let errorHandled = false;
lob.on('close', () => {
// console.log("lob.on 'close' event");
connection.commit((err) => {
if (err) {
if (!errorHandled) {
errorHandled = true;
reject(err);
}
} else {
console.log("Text inserted successfully.");
resolve();
}
});
});
lob.on('error', (err) => {
// console.log("lob.on 'error' event");
if (!errorHandled) {
errorHandled = true;
lob.close(() => {
reject(err);
});
}
});
console.log('Reading from ' + inFileName);
var inStream = fs.createReadStream(inFileName);
inStream.on('error', (err) => {
// console.log("inStream.on 'error' event");
if (!errorHandled) {
errorHandled = true;
reject(err);
}
});
inStream.pipe(lob); // copies the text to the LOB
});
await doStream;
} catch (err) {
console.error(err);
} finally {
if (connection) {
try {
await connection.close();
} catch (err) {
console.error(err);
}
}
}
}
run();