node-oracledb/examples/selectjsonblob.js

124 lines
3.5 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
* selectjsonblob.js
*
* DESCRIPTION
* Executes sample insert and query statements using a JSON column with BLOB storage.
* Requires Oracle Database 12.1.0.2, which has extensive JSON datatype support.
* See https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=ADJSN
*
* Use demo.sql to create the required table.
*
* This example requires node-oracledb 1.13 or later.
*
*****************************************************************************/
var async = require('async');
var oracledb = require('oracledb');
var dbConfig = require('./dbconfig.js');
var doconnect = function(cb) {
oracledb.getConnection(dbConfig, cb);
};
var dorelease = function(conn) {
conn.close(function (err) {
if (err)
console.error(err.message);
});
};
var checkver = function (conn, cb) {
if (conn.oracleServerVersion < 1201000200) {
return cb(new Error('This example only works with Oracle Database 12.1.0.2 or greater'), conn);
} else {
return cb(null, conn);
}
};
// Insert some JSON data
var doinsert = function (conn, cb) {
var data = { "userId": 2, "userName": "Bob", "location": "USA" };
var s = JSON.stringify(data);
var b = Buffer.from(s, 'utf8');
conn.execute(
"INSERT INTO j_purchaseorder_b (po_document) VALUES (:lobbv)",
{ lobbv: b },
// { autoCommit: true }, // uncomment if you want data to persist
function(err) {
if (err) {
return cb(err, conn);
} else {
console.log("Data inserted successfully.");
return cb(null, conn);
}
});
};
// Select JSON with JSON_EXISTS
var dojsonquery = function (conn, cb) {
console.log('Selecting JSON stored in a BLOB column:');
conn.execute(
"SELECT po_document FROM j_purchaseorder_b WHERE JSON_EXISTS (po_document, '$.location')",
[],
{ fetchInfo: { "PO_DOCUMENT": { type: oracledb.BUFFER } } }, // Fetch as a Buffer instead of a Stream
function(err, result) {
if (err)
return cb(err, conn);
if (result.rows.length === 0)
return cb(new Error('No results'), conn);
console.log(result.rows[0][0].toString('utf8'));
return cb(null, conn);
});
};
// Select a JSON value using dot-notation. This syntax requires Oracle Database 12.2
var dojsonquerydot = function (conn, cb) {
console.log('Selecting a JSON value:');
conn.execute(
"SELECT pob.po_document.location FROM j_purchaseorder_b pob",
function(err, result) {
if (err)
return cb(err, conn);
if (result.rows.length === 0)
return cb(new Error('No results'), conn);
console.log(result.rows[0][0]);
return cb(null, conn);
});
};
async.waterfall(
[
doconnect,
checkver,
doinsert,
dojsonquery,
dojsonquerydot
],
function (err, conn) {
if (err) { console.error("In waterfall error cb: ==>", err, "<=="); }
if (conn)
dorelease(conn);
});