165 lines
5.2 KiB
JavaScript
165 lines
5.2 KiB
JavaScript
/* Copyright (c) 2015, 2022, Oracle and/or its affiliates. */
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/******************************************************************************
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*
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* This software is dual-licensed to you under the Universal Permissive License
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* (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
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* 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose
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* either license.
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*
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* If you elect to accept the software under the Apache License, Version 2.0,
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* the following applies:
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://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,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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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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* selectjson.js
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*
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* DESCRIPTION
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* Shows some JSON features of Oracle Database 21c.
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* See https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=ADJSN
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*
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* For JSON with older databases see selectjsonblob.js
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*
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* This example requires node-oracledb 5.1 or later.
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*
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* This example uses Node 8's async/await syntax.
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*
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*****************************************************************************/
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const fs = require('fs');
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const oracledb = require('oracledb');
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const dbConfig = require('./dbconfig.js');
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// On Windows and macOS, you can specify the directory containing the Oracle
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// Client Libraries at runtime, or before Node.js starts. On other platforms
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// the system library search path must always be set before Node.js is started.
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// See the node-oracledb installation documentation.
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// If the search path is not correct, you will get a DPI-1047 error.
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let libPath;
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if (process.platform === 'win32') { // Windows
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libPath = 'C:\\oracle\\instantclient_19_12';
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} else if (process.platform === 'darwin') { // macOS
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libPath = process.env.HOME + '/Downloads/instantclient_19_8';
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}
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if (libPath && fs.existsSync(libPath)) {
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oracledb.initOracleClient({ libDir: libPath });
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}
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oracledb.extendedMetaData = true;
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async function run() {
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let connection;
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try {
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connection = await oracledb.getConnection(dbConfig);
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if (connection.oracleServerVersion < 2100000000) {
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throw new Error('This example requires Oracle Database 21.1 or later. Try selectjsonblob.js.');
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}
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console.log('1. Creating Table');
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try {
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await connection.execute(`DROP TABLE no_purchaseorder`);
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} catch (e) {
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if (e.errorNum != 942)
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console.error(e);
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}
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connection.execute(`CREATE TABLE no_purchaseorder (po_document JSON)`);
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console.log('2. Inserting Data');
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const inssql = `INSERT INTO no_purchaseorder (po_document) VALUES (:bv)`;
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const data = { "userId": 1, "userName": "Anna", "location": "Australia" };
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if (oracledb.oracleClientVersion >= 2100000000) {
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await connection.execute(inssql, { bv: { val: data, type: oracledb.DB_TYPE_JSON } });
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} else {
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// With older client versions, insert as a JSON string
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const s = JSON.stringify(data);
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const b = Buffer.from(s, 'utf8');
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await connection.execute(inssql, { bv: { val: b } });
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}
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let result, j;
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console.log('3. Selecting JSON stored in a column');
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result = await connection.execute(
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`SELECT po_document
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FROM no_purchaseorder
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WHERE JSON_EXISTS (po_document, '$.location')
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OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY`
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);
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if (result.metaData[0].fetchType == oracledb.DB_TYPE_JSON) {
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j = result.rows[0][0];
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} else {
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// Oracle Client libraries < 21 will return a BLOB
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const d = await result.rows[0][0].getData();
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j = await JSON.parse(d);
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}
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console.log('Query results: ', j);
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console.log('4. Using JSON_VALUE to extract a value from a JSON column');
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result = await connection.execute(
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`SELECT JSON_VALUE(po_document, '$.location')
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FROM no_purchaseorder
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OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY`
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);
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console.log('Query results: ', result.rows[0][0]); // just show first record
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console.log('5. Using dot-notation to extract a value from a JSON column');
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result = await connection.execute(
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`SELECT po.po_document.location
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FROM no_purchaseorder po
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OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY`
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);
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if (result.metaData[0].fetchType == oracledb.DB_TYPE_JSON) {
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j = result.rows[0][0];
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} else {
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// Oracle Client libraries < 21 will return a BLOB
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const d = await result.rows[0][0].getData();
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j = await JSON.parse(d);
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}
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console.log('Query results: ', j);
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console.log('6. Using JSON_OBJECT to extract relational data as JSON');
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result = await connection.execute(
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`SELECT JSON_OBJECT('key' IS d.dummy) dummy
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FROM dual d`
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);
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for (let row of result.rows) {
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console.log('Query results: ', row[0]);
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}
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} catch (err) {
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console.error(err);
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} finally {
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if (connection) {
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try {
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await connection.close();
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} catch (err) {
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console.error(err);
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}
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}
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}
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}
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run();
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