121 lines
3.4 KiB
JavaScript
121 lines
3.4 KiB
JavaScript
/* Copyright (c) 2016, 2018 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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* lobselect.js
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*
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* DESCRIPTION
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* SELECTs a CLOB and displays output to the console.
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* SELECTs a BLOB and writes it to a file.
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*
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* 'Large' LOBs should be streamed as shown in lobstream1.js
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*
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* Use demo.sql to create the required table or do:
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* DROP TABLE mylobs;
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* CREATE TABLE mylobs (id NUMBER, c CLOB, b BLOB);
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*
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* Run lobinsert1.js to load data before running this example.
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*
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*****************************************************************************/
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var fs = require('fs');
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var async = require('async');
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var oracledb = require('oracledb');
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var dbConfig = require('./dbconfig.js');
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// force all CLOBs to be returned as Strings
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oracledb.fetchAsString = [ oracledb.CLOB ];
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// force all BLOBs to be returned as Buffers
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oracledb.fetchAsBuffer = [ oracledb.BLOB ];
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var doconnect = function(cb) {
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oracledb.getConnection(
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{
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user : dbConfig.user,
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password : dbConfig.password,
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connectString : dbConfig.connectString
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},
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function(err, conn) {
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if (err)
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return cb(err);
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else {
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return cb(null, conn);
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}
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});
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};
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var dorelease = function(conn) {
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conn.close(function (err) {
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if (err)
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console.error(err.message);
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});
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};
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var doclobquery = function(conn, cb) {
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conn.execute(
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"SELECT c FROM mylobs WHERE id = :idbv",
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[1],
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// An alternative to oracledb.fetchAsString is to use fetchInfo on the column:
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// { fetchInfo: {"C": {type: oracledb.STRING}} },
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function(err, result) {
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if (err) {
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return cb(err, conn);
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}
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if (result.rows.length === 0) {
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return cb(new Error("No results. Did you run lobinsert1.js?"), conn);
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}
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var clob = result.rows[0][0];
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console.log('The CLOB was: ');
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console.log(clob);
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return cb(null, conn);
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});
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};
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var doblobquery = function(conn, cb) {
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conn.execute(
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"SELECT b FROM mylobs WHERE id = :idbv",
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[2],
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// An alternative to oracledb.fetchAsBuffer is to use fetchInfo on the column:
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// { fetchInfo: {"B": {type: oracledb.BUFFER}} },
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function(err, result) {
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if (err) {
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return cb(err, conn);
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}
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if (result.rows.length === 0) {
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return cb(new Error("No results. Did you run lobinsert1.js?"), conn);
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}
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var blob = result.rows[0][0];
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console.log('Writing BLOB to lobselectout.jpg');
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fs.writeFile('lobselectout.jpg', blob, "binary", function(err) {
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return cb(err, conn);
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});
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});
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};
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// Connect and call the CLOB example
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async.waterfall([
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doconnect,
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doclobquery,
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doblobquery
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],
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function (err, conn) {
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if (err) { console.error("In waterfall error cb: ==>", err, "<=="); }
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if (conn)
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dorelease(conn);
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});
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