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Add support for fetching CLOB columns as STRINGs with oracledb.fetchAsString and fetchInfo
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-461
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12 files changed

+1268
-461
lines changed

‎doc/api.md

Lines changed: 260 additions & 195 deletions
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‎examples/lobselect.js

Lines changed: 94 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,94 @@
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/* Copyright (c) 2016, 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 it to the screen.
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*
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* 'Large' CLOBs 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 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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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 doquery = 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 a column:
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// { fetchInfo: {"C": {type: oracledb.STRING}} },
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function(err, result)
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{
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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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// Connect and call the CLOB example
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async.waterfall([
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doconnect,
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doquery
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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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});

‎examples/selectjsonclob.js

Lines changed: 10 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -74,32 +74,18 @@ var dojsonquery = function (conn, cb) {
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console.log('Selecting JSON stored in a CLOB column');
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conn.execute(
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"SELECT po_document FROM j_purchaseorder_c WHERE JSON_EXISTS (po_document, '$.location')",
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[],
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{ fetchInfo: { "PO_DOCUMENT": { type: oracledb.STRING} } }, // Fetch as a String instead of a Stream
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function(err, result)
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{
79-
if (err) { return cb(err, conn); }
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if (result.rows.length === 0) { return cb(new Error('No results'), conn); }
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if (err)
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return cb(err, conn);
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if (result.rows.length === 0)
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return cb(new Error('No results'), conn);
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var clob = '';
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var lob = result.rows[0][0]; // just show first record
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if (lob === null) { return cb(new Error('CLOB was NULL'), conn); }
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lob.setEncoding('utf8'); // set the encoding so we get a 'string' not a 'buffer'
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lob.on('data',
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function(chunk)
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{
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clob += chunk;
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});
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lob.on('close',
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function()
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{
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var js = JSON.parse(clob);
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console.log('Query results: ', js);
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return cb(null, conn);
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});
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lob.on('error',
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function(err)
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{
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return cb(err, conn);
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});
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console.log('Query results:');
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console.log(result.rows);
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return cb(null, conn);
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});
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};
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@@ -108,7 +94,7 @@ async.waterfall(
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doconnect,
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checkver,
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doinsert,
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dojsonquery,
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dojsonquery
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],
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function (err, conn) {
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if (err) { console.error("In waterfall error cb: ==>", err, "<=="); }

‎src/dpi/include/dpiStmt.h

Lines changed: 47 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -141,6 +141,48 @@ typedef enum
141141
#endif
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143143

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// Forward declaration
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class Stmt;
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148+
// Application (Driver) level callback function prototype
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typedef int (*bindcbtype) (void *ctx, DPI_SZ_TYPE nRows, unsigned int bndpos,
150+
unsigned long iter,
151+
unsigned long index, void **bufpp, void **alenp,
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void **indpp, unsigned short **rcodepp,
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unsigned char *piecep );
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155+
// Application (Driver) level callback funciton prototype
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typedef int (*definecbtype) ( void *ctx, unsigned long definePos,
157+
unsigned long iter, unsigned long *prevIter,
158+
void **bufpp, void **alenp, void **indpp,
159+
unsigned short **rcodepp );
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161+
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// Bind-Dynamic Context structure - used for DML RETURNING case.
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typedef struct
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{
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bindcbtype callbackfn; /* Application specific callback */
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void* data; /* Data for application specific callback */
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unsigned long nrows; /* number of rows affected by this DML */
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unsigned long iter; /* iteration - used in Array Bind */
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unsigned int bndpos; /* position in the bind array */
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short nullInd; /* DML RETURNING: to pass null from inbind cbk */
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Stmt *dpistmt; /* DPI Statement Implementation */
173+
} DpiBindCallbackCtx;
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// Define-Dynamic Context structure - used for CLOB-as-STRING case
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typedef struct
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{
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definecbtype callbackfn; /* Application specific callback */
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void *data; /* data for application specific callback */
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unsigned int definePos; /* 0-based define column position */
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unsigned long prevIter; /* earlier iter, used to detect iter changing */
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} DpiDefineCallbackCtx;
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144186
typedef struct MetaData
145187
{
146188
unsigned char *colName; // column name
@@ -158,12 +200,6 @@ typedef struct MetaData
158200
} MetaData;
159201

160202

161-
// Application (Driver) level callback function prototype
162-
typedef int (*cbtype) (void *ctx, DPI_SZ_TYPE nRows, unsigned int bndpos,
163-
unsigned long iter,
164-
unsigned long index, dvoid **bufpp, void **alenp,
165-
dvoid **indpp, unsigned short **rcodepp,
166-
unsigned char *piecep );
167203

168204
class Stmt
169205
{
@@ -187,21 +223,21 @@ class Stmt
187223
virtual void bind(unsigned int pos, unsigned short type, void *buf,
188224
DPI_SZ_TYPE bufSize, short *ind, DPI_BUFLEN_TYPE *bufLen,
189225
unsigned int maxarr_len, unsigned int *curelen,
190-
void *data,
191-
cbtype cb = NULL ) = 0;
226+
DpiBindCallbackCtx *ctx = NULL) = 0;
192227

193228
virtual void bind(const unsigned char *name, int nameLen,
194229
unsigned int bndpos,
195230
unsigned short type, void *buf, DPI_SZ_TYPE bufSize,
196231
short *ind, DPI_BUFLEN_TYPE *bufLen,
197232
unsigned int maxarr_len, unsigned int *curelen,
198-
void *data,
199-
cbtype cb = NULL ) = 0;
233+
DpiBindCallbackCtx *ctx = NULL ) = 0;
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201235
virtual void execute ( int numIterations, bool autoCommit = false) = 0;
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203237
virtual void define(unsigned int pos, unsigned short type, void *buf,
204-
DPI_SZ_TYPE bufSize, short *ind, DPI_BUFLEN_TYPE *bufLen) = 0;
238+
DPI_SZ_TYPE bufSize, short *ind,
239+
DPI_BUFLEN_TYPE *bufLen,
240+
DpiDefineCallbackCtx *ctx = NULL ) = 0;
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206242
virtual void fetch(unsigned int numRows = 1) = 0;
207243

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