Class: Mysql2::Statement

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/mysql2/statement.rb,
ext/mysql2/statement.c

Instance Method Summary collapse

Instance Method Details

#executeObject

Executes the current prepared statement, returns result.


247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
# File 'ext/mysql2/statement.c', line 247

static VALUE rb_mysql_stmt_execute(int argc, VALUE *argv, VALUE self) {
  MYSQL_BIND *bind_buffers = NULL;
  unsigned long *length_buffers = NULL;
  unsigned long bind_count;
  unsigned long i;
  MYSQL_STMT *stmt;
  MYSQL_RES *metadata;
  VALUE opts;
  VALUE current;
  VALUE resultObj;
  VALUE *params_enc = NULL;
  int is_streaming;
  rb_encoding *conn_enc;

  GET_STATEMENT(self);
  GET_CLIENT(stmt_wrapper->client);

  conn_enc = rb_to_encoding(wrapper->encoding);

  stmt = stmt_wrapper->stmt;
  bind_count = mysql_stmt_param_count(stmt);

  // Get count of ordinary arguments, and extract hash opts/keyword arguments
  // Use a local scope to avoid leaking the temporary count variable
  {
    int c = rb_scan_args(argc, argv, "*:", NULL, &opts);
    if (c != (long)bind_count) {
      rb_raise(cMysql2Error, "Bind parameter count (%ld) doesn't match number of arguments (%d)", bind_count, c);
    }
  }

  // setup any bind variables in the query
  if (bind_count > 0) {
    // Scratch space for string encoding exports, allocate on the stack
    params_enc = alloca(sizeof(VALUE) * bind_count);
    bind_buffers = xcalloc(bind_count, sizeof(MYSQL_BIND));
    length_buffers = xcalloc(bind_count, sizeof(unsigned long));

    for (i = 0; i < bind_count; i++) {
      bind_buffers[i].buffer = NULL;
      params_enc[i] = Qnil;

      switch (TYPE(argv[i])) {
        case T_NIL:
          bind_buffers[i].buffer_type = MYSQL_TYPE_NULL;
          break;
        case T_FIXNUM:
#if SIZEOF_INT < SIZEOF_LONG
          bind_buffers[i].buffer_type = MYSQL_TYPE_LONGLONG;
          bind_buffers[i].buffer = xmalloc(sizeof(long long int));
          *(long*)(bind_buffers[i].buffer) = FIX2LONG(argv[i]);
#else
          bind_buffers[i].buffer_type = MYSQL_TYPE_LONG;
          bind_buffers[i].buffer = xmalloc(sizeof(int));
          *(long*)(bind_buffers[i].buffer) = FIX2INT(argv[i]);
#endif
          break;
        case T_BIGNUM:
          {
            LONG_LONG num;
            if (my_big2ll(argv[i], &num) == 0) {
              bind_buffers[i].buffer_type = MYSQL_TYPE_LONGLONG;
              bind_buffers[i].buffer = xmalloc(sizeof(long long int));
              *(LONG_LONG*)(bind_buffers[i].buffer) = num;
            } else {
              /* The bignum was larger than we can fit in LONG_LONG, send it as a string */
              bind_buffers[i].buffer_type = MYSQL_TYPE_NEWDECIMAL;
              params_enc[i] = rb_str_export_to_enc(rb_big2str(argv[i], 10), conn_enc);
              set_buffer_for_string(&bind_buffers[i], &length_buffers[i], params_enc[i]);
            }
          }
          break;
        case T_FLOAT:
          bind_buffers[i].buffer_type = MYSQL_TYPE_DOUBLE;
          bind_buffers[i].buffer = xmalloc(sizeof(double));
          *(double*)(bind_buffers[i].buffer) = NUM2DBL(argv[i]);
          break;
        case T_STRING:
          bind_buffers[i].buffer_type = MYSQL_TYPE_STRING;

          params_enc[i] = argv[i];
          params_enc[i] = rb_str_export_to_enc(params_enc[i], conn_enc);
          set_buffer_for_string(&bind_buffers[i], &length_buffers[i], params_enc[i]);
          break;
        case T_TRUE:
          bind_buffers[i].buffer_type = MYSQL_TYPE_TINY;
          bind_buffers[i].buffer = xmalloc(sizeof(signed char));
          *(signed char*)(bind_buffers[i].buffer) = 1;
          break;
        case T_FALSE:
          bind_buffers[i].buffer_type = MYSQL_TYPE_TINY;
          bind_buffers[i].buffer = xmalloc(sizeof(signed char));
          *(signed char*)(bind_buffers[i].buffer) = 0;
          break;
        default:
          // TODO: what Ruby type should support MYSQL_TYPE_TIME
          if (CLASS_OF(argv[i]) == rb_cTime || CLASS_OF(argv[i]) == cDateTime) {
            MYSQL_TIME t;
            VALUE rb_time = argv[i];

            bind_buffers[i].buffer_type = MYSQL_TYPE_DATETIME;
            bind_buffers[i].buffer = xmalloc(sizeof(MYSQL_TIME));

            memset(&t, 0, sizeof(MYSQL_TIME));
            t.neg = 0;

            if (CLASS_OF(argv[i]) == rb_cTime) {
              t.second_part = FIX2INT(rb_funcall(rb_time, intern_usec, 0));
            } else if (CLASS_OF(argv[i]) == cDateTime) {
              t.second_part = NUM2DBL(rb_funcall(rb_time, intern_sec_fraction, 0)) * 1000000;
            }

            t.second = FIX2INT(rb_funcall(rb_time, intern_sec, 0));
            t.minute = FIX2INT(rb_funcall(rb_time, intern_min, 0));
            t.hour = FIX2INT(rb_funcall(rb_time, intern_hour, 0));
            t.day = FIX2INT(rb_funcall(rb_time, intern_day, 0));
            t.month = FIX2INT(rb_funcall(rb_time, intern_month, 0));
            t.year = FIX2INT(rb_funcall(rb_time, intern_year, 0));

            *(MYSQL_TIME*)(bind_buffers[i].buffer) = t;
          } else if (CLASS_OF(argv[i]) == cDate) {
            MYSQL_TIME t;
            VALUE rb_time = argv[i];

            bind_buffers[i].buffer_type = MYSQL_TYPE_DATE;
            bind_buffers[i].buffer = xmalloc(sizeof(MYSQL_TIME));

            memset(&t, 0, sizeof(MYSQL_TIME));
            t.second_part = 0;
            t.neg = 0;
            t.day = FIX2INT(rb_funcall(rb_time, intern_day, 0));
            t.month = FIX2INT(rb_funcall(rb_time, intern_month, 0));
            t.year = FIX2INT(rb_funcall(rb_time, intern_year, 0));

            *(MYSQL_TIME*)(bind_buffers[i].buffer) = t;
          } else if (CLASS_OF(argv[i]) == cBigDecimal) {
            bind_buffers[i].buffer_type = MYSQL_TYPE_NEWDECIMAL;

            // DECIMAL are represented with the "string representation of the
            // original server-side value", see
            // https://dev.mysql.com/doc/refman/5.7/en/c-api-prepared-statement-type-conversions.html
            // This should be independent of the locale used both on the server
            // and the client side.
            VALUE rb_val_as_string = rb_funcall(argv[i], intern_to_s, 0);

            params_enc[i] = rb_val_as_string;
            params_enc[i] = rb_str_export_to_enc(params_enc[i], conn_enc);
            set_buffer_for_string(&bind_buffers[i], &length_buffers[i], params_enc[i]);
          }
          break;
      }
    }

    // copies bind_buffers into internal storage
    if (mysql_stmt_bind_param(stmt, bind_buffers)) {
      FREE_BINDS;
      rb_raise_mysql2_stmt_error(stmt_wrapper);
    }
  }

  // Duplicate the options hash, merge! extra opts, put the copy into the Result object
  current = rb_hash_dup(rb_ivar_get(stmt_wrapper->client, intern_query_options));
  (void)RB_GC_GUARD(current);
  Check_Type(current, T_HASH);

  // Merge in hash opts/keyword arguments
  if (!NIL_P(opts)) {
    rb_funcall(current, intern_merge_bang, 1, opts);
  }

  is_streaming = (Qtrue == rb_hash_aref(current, sym_stream));

  // From stmt_execute to mysql_stmt_result_metadata to stmt_store_result, no
  // Ruby API calls are allowed so that GC is not invoked. If the connection is
  // in results-streaming-mode for Statement A, and in the middle Statement B
  // gets garbage collected, a message will be sent to the server notifying it
  // to release Statement B, resulting in the following error:
  //   Commands out of sync; you can't run this command now
  //
  // In streaming mode, statement execute must return a cursor because we
  // cannot prevent other Statement objects from being garbage collected
  // between fetches of each row of the result set. The following error
  // occurs if cursor mode is not set:
  //   Row retrieval was canceled by mysql_stmt_close

  if (is_streaming) {
    unsigned long type = CURSOR_TYPE_READ_ONLY;
    if (mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, &type)) {
      FREE_BINDS;
      rb_raise(cMysql2Error, "Unable to stream prepared statement, could not set CURSOR_TYPE_READ_ONLY");
    }
  }

  if ((VALUE)rb_thread_call_without_gvl(nogvl_stmt_execute, stmt, RUBY_UBF_IO, 0) == Qfalse) {
    FREE_BINDS;
    rb_raise_mysql2_stmt_error(stmt_wrapper);
  }

  FREE_BINDS;

  metadata = mysql_stmt_result_metadata(stmt);
  if (metadata == NULL) {
    if (mysql_stmt_errno(stmt) != 0) {
      // either CR_OUT_OF_MEMORY or CR_UNKNOWN_ERROR. both fatal.
      wrapper->active_thread = Qnil;
      rb_raise_mysql2_stmt_error(stmt_wrapper);
    }
    // no data and no error, so query was not a SELECT
    return Qnil;
  }

  if (!is_streaming) {
    // recieve the whole result set from the server
    if (mysql_stmt_store_result(stmt)) {
      mysql_free_result(metadata);
      rb_raise_mysql2_stmt_error(stmt_wrapper);
    }
    wrapper->active_thread = Qnil;
  }

  resultObj = rb_mysql_result_to_obj(stmt_wrapper->client, wrapper->encoding, current, metadata, self);

  rb_mysql_set_server_query_flags(wrapper->client, resultObj);

  if (!is_streaming) {
    // cache all result
    rb_funcall(resultObj, intern_each, 0);
  }

  return resultObj;
}

#affected_rowsObject

Returns the number of rows changed, deleted, or inserted.


547
548
549
550
551
552
553
554
555
556
557
# File 'ext/mysql2/statement.c', line 547

static VALUE rb_mysql_stmt_affected_rows(VALUE self) {
  my_ulonglong affected;
  GET_STATEMENT(self);

  affected = mysql_stmt_affected_rows(stmt_wrapper->stmt);
  if (affected == (my_ulonglong)-1) {
    rb_raise_mysql2_stmt_error(stmt_wrapper);
  }

  return ULL2NUM(affected);
}

#closeObject

Explicitly closing this will free up server resources immediately rather than waiting for the garbage collector. Useful if you're managing your own prepared statement cache.


566
567
568
569
570
571
# File 'ext/mysql2/statement.c', line 566

static VALUE rb_mysql_stmt_close(VALUE self) {
  GET_STATEMENT(self);
  stmt_wrapper->closed = 1;
  rb_thread_call_without_gvl(nogvl_stmt_close, stmt_wrapper, RUBY_UBF_IO, 0);
  return Qnil;
}

#execute(*args, **kwargs) ⇒ Object


5
6
7
8
9
# File 'lib/mysql2/statement.rb', line 5

def execute(*args, **kwargs)
  Thread.handle_interrupt(::Mysql2::Util::TIMEOUT_ERROR_CLASS => :never) do
    _execute(*args, **kwargs)
  end
end

#field_countObject

Returns the number of fields the prepared statement returns.


156
157
158
159
160
# File 'ext/mysql2/statement.c', line 156

static VALUE rb_mysql_stmt_field_count(VALUE self) {
  GET_STATEMENT(self);

  return UINT2NUM(mysql_stmt_field_count(stmt_wrapper->stmt));
}

#fieldsObject

Returns a list of fields that will be returned by this statement.


483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
# File 'ext/mysql2/statement.c', line 483

static VALUE rb_mysql_stmt_fields(VALUE self) {
  MYSQL_FIELD *fields;
  MYSQL_RES *metadata;
  unsigned int field_count;
  unsigned int i;
  VALUE field_list;
  MYSQL_STMT* stmt;
  rb_encoding *default_internal_enc, *conn_enc;
  GET_STATEMENT(self);
  GET_CLIENT(stmt_wrapper->client);
  stmt = stmt_wrapper->stmt;

  default_internal_enc = rb_default_internal_encoding();
  {
    GET_CLIENT(stmt_wrapper->client);
    conn_enc = rb_to_encoding(wrapper->encoding);
  }

  metadata = mysql_stmt_result_metadata(stmt);
  if (metadata == NULL) {
    if (mysql_stmt_errno(stmt) != 0) {
      // either CR_OUT_OF_MEMORY or CR_UNKNOWN_ERROR. both fatal.
      wrapper->active_thread = Qnil;
      rb_raise_mysql2_stmt_error(stmt_wrapper);
    }
    // no data and no error, so query was not a SELECT
    return Qnil;
  }

  fields      = mysql_fetch_fields(metadata);
  field_count = mysql_stmt_field_count(stmt);
  field_list  = rb_ary_new2((long)field_count);

  for (i = 0; i < field_count; i++) {
    VALUE rb_field;

    rb_field = rb_str_new(fields[i].name, fields[i].name_length);
    rb_enc_associate(rb_field, conn_enc);
    if (default_internal_enc) {
     rb_field = rb_str_export_to_enc(rb_field, default_internal_enc);
   }

    rb_ary_store(field_list, (long)i, rb_field);
  }

  mysql_free_result(metadata);
  return field_list;
}

#last_idObject

Returns the AUTO_INCREMENT value from the executed INSERT or UPDATE.


537
538
539
540
# File 'ext/mysql2/statement.c', line 537

static VALUE rb_mysql_stmt_last_id(VALUE self) {
  GET_STATEMENT(self);
  return ULL2NUM(mysql_stmt_insert_id(stmt_wrapper->stmt));
}

#param_countObject

Returns the number of parameters the prepared statement expects.


146
147
148
149
150
# File 'ext/mysql2/statement.c', line 146

static VALUE rb_mysql_stmt_param_count(VALUE self) {
  GET_STATEMENT(self);

  return ULL2NUM(mysql_stmt_param_count(stmt_wrapper->stmt));
}