php-src/ext/pdo_mysql/mysql_statement.c

/*
  +----------------------------------------------------------------------+
  | Copyright (c) The PHP Group                                          |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | https://www.php.net/license/3_01.txt                                 |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: George Schlossnagle <george@omniti.com>                      |
  |         Wez Furlong <wez@php.net>                                    |
  |         Johannes Schlueter <johannes@mysql.com>                      |
  +----------------------------------------------------------------------+
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"
#include "php_ini.h"
#include "ext/standard/info.h"
#include "pdo/php_pdo.h"
#include "pdo/php_pdo_driver.h"
#include "php_pdo_mysql.h"
#include "php_pdo_mysql_int.h"
#include "zend_interfaces.h"

#ifdef PDO_USE_MYSQLND
#	define pdo_mysql_stmt_execute_prepared(stmt) pdo_mysql_stmt_execute_prepared_mysqlnd(stmt)
#else
#	define pdo_mysql_stmt_execute_prepared(stmt) pdo_mysql_stmt_execute_prepared_libmysql(stmt)
#endif

static void pdo_mysql_free_result(pdo_mysql_stmt *S)
{
	if (S->result) {
#ifndef PDO_USE_MYSQLND
		if (S->bound_result) {
			/* We can't use stmt->column_count here, because it gets reset before the
			 * next_rowset handler is called. */
			unsigned column_count = mysql_num_fields(S->result);
			for (unsigned i = 0; i < column_count; i++) {
				efree(S->bound_result[i].buffer);
			}

			efree(S->bound_result);
			efree(S->out_null);
			efree(S->out_length);
			S->bound_result = NULL;
		}
#else
		if (S->current_row) {
			unsigned column_count = mysql_num_fields(S->result);
			for (unsigned i = 0; i < column_count; i++) {
				zval_ptr_dtor_nogc(&S->current_row[i]);
			}
			efree(S->current_row);
			S->current_row = NULL;
		}
#endif
		mysql_free_result(S->result);
		S->result = NULL;
	}
}

static int pdo_mysql_stmt_dtor(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_dtor");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);

	pdo_mysql_free_result(S);
	if (S->einfo.errmsg) {
		pefree(S->einfo.errmsg, stmt->dbh->is_persistent);
		S->einfo.errmsg = NULL;
	}
	if (S->stmt) {
		mysql_stmt_close(S->stmt);
		S->stmt = NULL;
	}

#ifndef PDO_USE_MYSQLND
	if (S->params) {
		efree(S->params);
	}
	if (S->in_null) {
		efree(S->in_null);
	}
	if (S->in_length) {
		efree(S->in_length);
	}
#endif

	if (!S->done && !Z_ISUNDEF(stmt->database_object_handle)
		&& IS_OBJ_VALID(EG(objects_store).object_buckets[Z_OBJ_HANDLE(stmt->database_object_handle)])
		&& (!(OBJ_FLAGS(Z_OBJ(stmt->database_object_handle)) & IS_OBJ_FREE_CALLED))) {
		while (mysql_more_results(S->H->server)) {
			MYSQL_RES *res;
			if (mysql_next_result(S->H->server) != 0) {
				break;
			}

			res = mysql_store_result(S->H->server);
			if (res) {
				mysql_free_result(res);
			}
		}
	}

	efree(S);
	PDO_DBG_RETURN(1);
}
/* }}} */

static void pdo_mysql_stmt_set_row_count(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = stmt->driver_data;
	zend_long row_count = (zend_long) mysql_stmt_affected_rows(S->stmt);
	if (row_count != (zend_long)-1) {
		stmt->row_count = row_count;
	}
}
/* }}} */

static int pdo_mysql_fill_stmt_from_result(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
	pdo_mysql_db_handle *H = S->H;
	my_ulonglong row_count;
	PDO_DBG_ENTER("pdo_mysql_fill_stmt_from_result");

	row_count = mysql_affected_rows(H->server);
	if (row_count == (my_ulonglong)-1) {
		/* we either have a query that returned a result set or an error occurred
		   lets see if we have access to a result set */
		if (!H->buffered) {
			S->result = mysql_use_result(H->server);
		} else {
			S->result = mysql_store_result(H->server);
		}
		if (NULL == S->result) {
			pdo_mysql_error_stmt(stmt);
			PDO_DBG_RETURN(0);
		}

		stmt->row_count = (zend_long) mysql_num_rows(S->result);
		php_pdo_stmt_set_column_count(stmt, (int) mysql_num_fields(S->result));
		S->fields = mysql_fetch_fields(S->result);
	} else {
		/* this was a DML or DDL query (INSERT, UPDATE, DELETE, ... */
		stmt->row_count = (zend_long) row_count;
	}

	PDO_DBG_RETURN(1);
}
/* }}} */

static bool pdo_mysql_stmt_after_execute_prepared(pdo_stmt_t *stmt) {
	pdo_mysql_stmt *S = stmt->driver_data;
	pdo_mysql_db_handle *H = S->H;

#ifdef PDO_USE_MYSQLND
	/* For SHOW/DESCRIBE and others the column/field count is not available before execute. */
	php_pdo_stmt_set_column_count(stmt, mysql_stmt_field_count(S->stmt));
	for (int i = 0; i < stmt->column_count; i++) {
		mysqlnd_stmt_bind_one_result(S->stmt, i);
	}

	S->result = mysqlnd_stmt_result_metadata(S->stmt);
	if (S->result) {
		S->fields = mysql_fetch_fields(S->result);
		/* If buffered, pre-fetch all the data */
		if (H->buffered) {
			if (mysql_stmt_store_result(S->stmt)) {
				pdo_mysql_error_stmt(stmt);
				return false;
			}
		}
	}
#else
	/* figure out the result set format, if any */
	S->result = mysql_stmt_result_metadata(S->stmt);
	if (S->result) {
		int calc_max_length = H->buffered && S->max_length == 1;
		S->fields = mysql_fetch_fields(S->result);

		php_pdo_stmt_set_column_count(stmt, (int)mysql_num_fields(S->result));
		S->bound_result = ecalloc(stmt->column_count, sizeof(MYSQL_BIND));
		S->out_null = ecalloc(stmt->column_count, sizeof(my_bool));
		S->out_length = ecalloc(stmt->column_count, sizeof(zend_ulong));

		/* summon memory to hold the row */
		for (int i = 0; i < stmt->column_count; i++) {
			if (calc_max_length && S->fields[i].type == FIELD_TYPE_BLOB) {
				my_bool on = 1;
				mysql_stmt_attr_set(S->stmt, STMT_ATTR_UPDATE_MAX_LENGTH, &on);
				calc_max_length = 0;
			}
			switch (S->fields[i].type) {
				case FIELD_TYPE_INT24:
					S->bound_result[i].buffer_length = MAX_MEDIUMINT_WIDTH + 1;
					break;
				case FIELD_TYPE_LONG:
					S->bound_result[i].buffer_length = MAX_INT_WIDTH + 1;
					break;
				case FIELD_TYPE_LONGLONG:
					S->bound_result[i].buffer_length = MAX_BIGINT_WIDTH + 1;
					break;
				case FIELD_TYPE_TINY:
					S->bound_result[i].buffer_length = MAX_TINYINT_WIDTH + 1;
					break;
				case FIELD_TYPE_SHORT:
					S->bound_result[i].buffer_length = MAX_SMALLINT_WIDTH + 1;
					break;
				default:
					S->bound_result[i].buffer_length =
						S->fields[i].max_length? S->fields[i].max_length:
						S->fields[i].length;
					/* work-around for longtext and alike */
					if (S->bound_result[i].buffer_length > H->max_buffer_size) {
						S->bound_result[i].buffer_length = H->max_buffer_size;
					}
			}

			/* there are cases where the length reported by mysql is too short.
			 * eg: when describing a table that contains an enum column. Since
			 * we have no way of knowing the true length either, we'll bump up
			 * our buffer size to a reasonable size, just in case */
			if (S->fields[i].max_length == 0 && S->bound_result[i].buffer_length < 128 && MYSQL_TYPE_VAR_STRING) {
				S->bound_result[i].buffer_length = 128;
			}

			S->out_length[i] = 0;

			S->bound_result[i].buffer = emalloc(S->bound_result[i].buffer_length);
			S->bound_result[i].is_null = &S->out_null[i];
			S->bound_result[i].length = &S->out_length[i];
			S->bound_result[i].buffer_type = MYSQL_TYPE_STRING;
		}

		if (mysql_stmt_bind_result(S->stmt, S->bound_result)) {
			pdo_mysql_error_stmt(stmt);
			PDO_DBG_RETURN(0);
		}

		/* if buffered, pre-fetch all the data */
		if (H->buffered) {
			if (mysql_stmt_store_result(S->stmt)) {
				pdo_mysql_error_stmt(stmt);
				PDO_DBG_RETURN(0);
			}
		}
	}
#endif

	pdo_mysql_stmt_set_row_count(stmt);
	return true;
}

#ifndef PDO_USE_MYSQLND
static int pdo_mysql_stmt_execute_prepared_libmysql(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_execute_prepared_libmysql");

	/* (re)bind the parameters */
	if (mysql_stmt_bind_param(S->stmt, S->params) || mysql_stmt_execute(S->stmt)) {
		if (S->params) {
			memset(S->params, 0, S->num_params * sizeof(MYSQL_BIND));
		}
		pdo_mysql_error_stmt(stmt);
		if (mysql_stmt_errno(S->stmt) == 2057) {
			/* CR_NEW_STMT_METADATA makes the statement unusable */
			S->stmt = NULL;
		}
		PDO_DBG_RETURN(0);
	}

	PDO_DBG_RETURN(pdo_mysql_stmt_after_execute_prepared(stmt));
}
/* }}} */
#endif

#ifdef PDO_USE_MYSQLND
static int pdo_mysql_stmt_execute_prepared_mysqlnd(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_execute_prepared_mysqlnd");

	if (mysql_stmt_execute(S->stmt)) {
		pdo_mysql_error_stmt(stmt);
		PDO_DBG_RETURN(0);
	}

	PDO_DBG_RETURN(pdo_mysql_stmt_after_execute_prepared(stmt));
}
/* }}} */
#endif

static int pdo_mysql_stmt_execute(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
	pdo_mysql_db_handle *H = S->H;
	PDO_DBG_ENTER("pdo_mysql_stmt_execute");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);

	/* ensure that we free any previous unfetched results */
	pdo_mysql_free_result(S);
	S->done = 0;

	if (S->stmt) {
		uint32_t num_bound_params =
			stmt->bound_params ? zend_hash_num_elements(stmt->bound_params) : 0;
		if (num_bound_params < (uint32_t) S->num_params) {
			/* too few parameter bound */
			PDO_DBG_ERR("too few parameters bound");
			strcpy(stmt->error_code, "HY093");
			PDO_DBG_RETURN(0);
		}

		PDO_DBG_RETURN(pdo_mysql_stmt_execute_prepared(stmt));
	}

	if (mysql_real_query(H->server, ZSTR_VAL(stmt->active_query_string), ZSTR_LEN(stmt->active_query_string)) != 0) {
		pdo_mysql_error_stmt(stmt);
		PDO_DBG_RETURN(0);
	}

	PDO_DBG_RETURN(pdo_mysql_fill_stmt_from_result(stmt));
}
/* }}} */

static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
	pdo_mysql_db_handle *H = S->H;
	PDO_DBG_ENTER("pdo_mysql_stmt_next_rowset");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);

	/* ensure that we free any previous unfetched results */
	pdo_mysql_free_result(S);

	if (S->stmt) {
		mysql_stmt_free_result(S->stmt);
		if (mysql_stmt_next_result(S->stmt)) {
			pdo_mysql_error_stmt(stmt);
			S->done = 1;
			PDO_DBG_RETURN(0);
		}
		PDO_DBG_RETURN(pdo_mysql_stmt_after_execute_prepared(stmt));
	} else {
		if (mysql_next_result(H->server)) {
			pdo_mysql_error_stmt(stmt);
			S->done = 1;
			PDO_DBG_RETURN(0);
		}
		PDO_DBG_RETURN(pdo_mysql_fill_stmt_from_result(stmt));
	}
}
/* }}} */


static const char * const pdo_param_event_names[] =
{
	"PDO_PARAM_EVT_ALLOC",
	"PDO_PARAM_EVT_FREE",
	"PDO_PARAM_EVT_EXEC_PRE",
	"PDO_PARAM_EVT_EXEC_POST",
	"PDO_PARAM_EVT_FETCH_PRE",
	"PDO_PARAM_EVT_FETCH_POST",
	"PDO_PARAM_EVT_NORMALIZE",
};

#ifndef PDO_USE_MYSQLND
static unsigned char libmysql_false_buffer = 0;
static unsigned char libmysql_true_buffer = 1;
#endif

static int pdo_mysql_stmt_param_hook(pdo_stmt_t *stmt, struct pdo_bound_param_data *param, enum pdo_param_event event_type) /* {{{ */
{
	zval *parameter;
#ifndef PDO_USE_MYSQLND
	PDO_MYSQL_PARAM_BIND *b;
#endif
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_param_hook");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
	PDO_DBG_INF_FMT("event = %s", pdo_param_event_names[event_type]);
	if (S->stmt && param->is_param) {
		switch (event_type) {
			case PDO_PARAM_EVT_ALLOC:
				/* sanity check parameter number range */
				if (param->paramno < 0 || param->paramno >= S->num_params) {
					strcpy(stmt->error_code, "HY093");
					PDO_DBG_RETURN(0);
				}

#ifndef PDO_USE_MYSQLND
				b = &S->params[param->paramno];
				param->driver_data = b;
				b->is_null = &S->in_null[param->paramno];
				b->length = &S->in_length[param->paramno];
				/* recall how many parameters have been provided */
#endif
				PDO_DBG_RETURN(1);

			case PDO_PARAM_EVT_EXEC_PRE:
				if (!Z_ISREF(param->parameter)) {
					parameter = &param->parameter;
				} else {
					parameter = Z_REFVAL(param->parameter);
				}

#ifdef PDO_USE_MYSQLND
				if (PDO_PARAM_TYPE(param->param_type) == PDO_PARAM_NULL || (Z_TYPE_P(parameter) == IS_NULL)) {
					mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_NULL);
					PDO_DBG_RETURN(1);
				}
#else
				b = (PDO_MYSQL_PARAM_BIND*)param->driver_data;
				*b->is_null = 0;
				if (PDO_PARAM_TYPE(param->param_type) == PDO_PARAM_NULL || Z_TYPE_P(parameter) == IS_NULL) {
					*b->is_null = 1;
					b->buffer_type = MYSQL_TYPE_STRING;
					b->buffer = NULL;
					b->buffer_length = 0;
					*b->length = 0;
					PDO_DBG_RETURN(1);
				}
#endif /* PDO_USE_MYSQLND */

				switch (PDO_PARAM_TYPE(param->param_type)) {
					case PDO_PARAM_STMT:
						PDO_DBG_RETURN(0);
					case PDO_PARAM_LOB:
						PDO_DBG_INF("PDO_PARAM_LOB");
						if (!Z_ISREF(param->parameter)) {
							parameter = &param->parameter;
						} else {
							parameter = Z_REFVAL(param->parameter);
						}
						if (Z_TYPE_P(parameter) == IS_RESOURCE) {
							php_stream *stm = NULL;
							php_stream_from_zval_no_verify(stm, parameter);
							if (stm) {
								zend_string *mem = php_stream_copy_to_mem(stm, PHP_STREAM_COPY_ALL, 0);
								zval_ptr_dtor(parameter);
								ZVAL_STR(parameter, mem ? mem : ZSTR_EMPTY_ALLOC());
							} else {
								pdo_raise_impl_error(stmt->dbh, stmt, "HY105", "Expected a stream resource");
								return 0;
							}
						}
						/* fall through */

					default:
						;
				}

#ifdef PDO_USE_MYSQLND
				/* Is it really correct to check the zval's type? - But well, that's what the old code below does, too */
				PDO_DBG_INF_FMT("param->parameter->type=%d", Z_TYPE(param->parameter));
				if (!Z_ISREF(param->parameter)) {
					parameter = &param->parameter;
				} else {
					parameter = Z_REFVAL(param->parameter);
				}
				switch (Z_TYPE_P(parameter)) {
					case IS_STRING:
						mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_VAR_STRING);
						break;
					case IS_LONG:
#if SIZEOF_ZEND_LONG==8
						mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_LONGLONG);
#elif SIZEOF_ZEND_LONG==4
						mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_LONG);
#endif /* SIZEOF_LONG */
						break;
					case IS_TRUE:
					case IS_FALSE:
						mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_TINY);
						break;
					case IS_DOUBLE:
						mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_DOUBLE);
						break;
					case IS_OBJECT:
						if(zend_class_implements_interface(Z_OBJCE_P(parameter), zend_ce_stringable)) {
							mysqlnd_stmt_bind_one_param(S->stmt, param->paramno, parameter, MYSQL_TYPE_VAR_STRING);
							break;
						}
						ZEND_FALLTHROUGH;
					default:
						pdo_raise_impl_error(stmt->dbh, stmt, "HY105", "Expected a scalar value or null");
						PDO_DBG_RETURN(0);
				}

				PDO_DBG_RETURN(1);
#else
				PDO_DBG_INF_FMT("param->parameter->type=%d", Z_TYPE(param->parameter));
				if (!Z_ISREF(param->parameter)) {
					parameter = &param->parameter;
				} else {
					parameter = Z_REFVAL(param->parameter);
				}
				switch (Z_TYPE_P(parameter)) {
					case IS_STRING:
						b->buffer_type = MYSQL_TYPE_STRING;
						b->buffer = Z_STRVAL_P(parameter);
						b->buffer_length = Z_STRLEN_P(parameter);
						*b->length = Z_STRLEN_P(parameter);
						PDO_DBG_RETURN(1);

					case IS_FALSE:
						b->buffer_type = MYSQL_TYPE_TINY;
						b->buffer = &libmysql_false_buffer;
						PDO_DBG_RETURN(1);

					case IS_TRUE:
						b->buffer_type = MYSQL_TYPE_TINY;
						b->buffer = &libmysql_true_buffer;
						PDO_DBG_RETURN(1);

					case IS_LONG:
						b->buffer_type = MYSQL_TYPE_LONG;
						b->buffer = &Z_LVAL_P(parameter);
						PDO_DBG_RETURN(1);

					case IS_DOUBLE:
						b->buffer_type = MYSQL_TYPE_DOUBLE;
						b->buffer = &Z_DVAL_P(parameter);
						PDO_DBG_RETURN(1);

					case IS_OBJECT:
						if(zend_class_implements_interface(Z_OBJCE_P(parameter), zend_ce_stringable)) {
							convert_to_string(parameter);
							b->buffer_type = MYSQL_TYPE_STRING;
							b->buffer = Z_STRVAL_P(parameter);
							b->buffer_length = Z_STRLEN_P(parameter);
							*b->length = Z_STRLEN_P(parameter);
							PDO_DBG_RETURN(1);
						}
						ZEND_FALLTHROUGH;

					default:
						pdo_raise_impl_error(stmt->dbh, stmt, "HY105", "Expected a scalar value or null");
						PDO_DBG_RETURN(0);
				}
#endif /* PDO_USE_MYSQLND */
		case PDO_PARAM_EVT_FREE:
		case PDO_PARAM_EVT_EXEC_POST:
		case PDO_PARAM_EVT_FETCH_PRE:
		case PDO_PARAM_EVT_FETCH_POST:
		case PDO_PARAM_EVT_NORMALIZE:
			/* do nothing */
			break;
		}
	}

	PDO_DBG_RETURN(1);
}
/* }}} */

static int pdo_mysql_stmt_fetch(pdo_stmt_t *stmt, enum pdo_fetch_orientation ori, zend_long offset) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;

	if (!S->result) {
		PDO_DBG_RETURN(0);
	}

#ifdef PDO_USE_MYSQLND
	bool fetched_anything;

	PDO_DBG_ENTER("pdo_mysql_stmt_fetch");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
	if (S->stmt) {
		if (FAIL == mysqlnd_stmt_fetch(S->stmt, &fetched_anything) || !fetched_anything) {
			pdo_mysql_error_stmt(stmt);
			PDO_DBG_RETURN(0);
		}

		PDO_DBG_RETURN(1);
	}

	zval *row_data;
	if (mysqlnd_fetch_row_zval(S->result, &row_data, &fetched_anything) == FAIL) {
		pdo_mysql_error_stmt(stmt);
		PDO_DBG_RETURN(0);
	}

	if (!fetched_anything) {
		PDO_DBG_RETURN(0);
	}

	if (!S->current_row) {
		S->current_row = ecalloc(sizeof(zval), stmt->column_count);
	}
	for (unsigned i = 0; i < stmt->column_count; i++) {
		zval_ptr_dtor_nogc(&S->current_row[i]);
		ZVAL_COPY_VALUE(&S->current_row[i], &row_data[i]);
	}
	PDO_DBG_RETURN(1);
#else
	int ret;

	if (S->stmt) {
		ret = mysql_stmt_fetch(S->stmt);

#		ifdef MYSQL_DATA_TRUNCATED
		if (ret == MYSQL_DATA_TRUNCATED) {
			ret = 0;
		}
#		endif

		if (ret) {
			if (ret != MYSQL_NO_DATA) {
				pdo_mysql_error_stmt(stmt);
			}
			PDO_DBG_RETURN(0);
		}

		PDO_DBG_RETURN(1);
	}

	if ((S->current_data = mysql_fetch_row(S->result)) == NULL) {
		if (!S->H->buffered && mysql_errno(S->H->server)) {
			pdo_mysql_error_stmt(stmt);
		}
		PDO_DBG_RETURN(0);
	}

	S->current_lengths = mysql_fetch_lengths(S->result);
	PDO_DBG_RETURN(1);
#endif /* PDO_USE_MYSQLND */
}
/* }}} */

static int pdo_mysql_stmt_describe(pdo_stmt_t *stmt, int colno) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
	struct pdo_column_data *cols = stmt->columns;
	int i;

	PDO_DBG_ENTER("pdo_mysql_stmt_describe");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
	if (!S->result) {
		PDO_DBG_RETURN(0);
	}

	if (colno >= stmt->column_count) {
		/* error invalid column */
		PDO_DBG_RETURN(0);
	}

	/* fetch all on demand, this seems easiest
	** if we've been here before bail out
	*/
	if (cols[0].name) {
		PDO_DBG_RETURN(1);
	}
	for (i = 0; i < stmt->column_count; i++) {

		if (S->H->fetch_table_names) {
			cols[i].name = strpprintf(0, "%s.%s", S->fields[i].table, S->fields[i].name);
		} else {
#ifdef PDO_USE_MYSQLND
			cols[i].name = zend_string_copy(S->fields[i].sname);
#else
			cols[i].name = zend_string_init(S->fields[i].name, S->fields[i].name_length, 0);
#endif
		}

		cols[i].precision = S->fields[i].decimals;
		cols[i].maxlen = S->fields[i].length;
	}
	PDO_DBG_RETURN(1);
}
/* }}} */

static int pdo_mysql_stmt_get_col(
		pdo_stmt_t *stmt, int colno, zval *result, enum pdo_param_type *type) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_get_col");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
	if (!S->result) {
		PDO_DBG_RETURN(0);
	}

	if (colno >= stmt->column_count) {
		/* error invalid column */
		PDO_DBG_RETURN(0);
	}
#ifdef PDO_USE_MYSQLND
	if (S->stmt) {
		ZVAL_COPY(result, &S->stmt->data->result_bind[colno].zv);
	} else {
		ZVAL_COPY(result, &S->current_row[colno]);
	}
	PDO_DBG_RETURN(1);
#else
	if (S->stmt) {
		if (S->out_null[colno]) {
			PDO_DBG_RETURN(1);
		}

		size_t length = S->out_length[colno];
		if (length > S->bound_result[colno].buffer_length) {
			/* mysql lied about the column width */
			strcpy(stmt->error_code, "01004"); /* truncated */
			length = S->out_length[colno] = S->bound_result[colno].buffer_length;
		}
		ZVAL_STRINGL_FAST(result, S->bound_result[colno].buffer, length);
		PDO_DBG_RETURN(1);
	}

	if (S->current_data == NULL) {
		PDO_DBG_RETURN(0);
	}
	if (S->current_data[colno]) {
		ZVAL_STRINGL_FAST(result, S->current_data[colno], S->current_lengths[colno]);
	}
	PDO_DBG_RETURN(1);
#endif
} /* }}} */

static char *type_to_name_native(int type) /* {{{ */
{
#define PDO_MYSQL_NATIVE_TYPE_NAME(x)	case FIELD_TYPE_##x: return #x;

	switch (type) {
		PDO_MYSQL_NATIVE_TYPE_NAME(STRING)
		PDO_MYSQL_NATIVE_TYPE_NAME(VAR_STRING)
#ifdef FIELD_TYPE_TINY
		PDO_MYSQL_NATIVE_TYPE_NAME(TINY)
#endif
#ifdef FIELD_TYPE_BIT
		PDO_MYSQL_NATIVE_TYPE_NAME(BIT)
#endif
		PDO_MYSQL_NATIVE_TYPE_NAME(SHORT)
		PDO_MYSQL_NATIVE_TYPE_NAME(LONG)
		PDO_MYSQL_NATIVE_TYPE_NAME(LONGLONG)
		PDO_MYSQL_NATIVE_TYPE_NAME(INT24)
		PDO_MYSQL_NATIVE_TYPE_NAME(FLOAT)
		PDO_MYSQL_NATIVE_TYPE_NAME(DOUBLE)
		PDO_MYSQL_NATIVE_TYPE_NAME(DECIMAL)
#ifdef FIELD_TYPE_NEWDECIMAL
		PDO_MYSQL_NATIVE_TYPE_NAME(NEWDECIMAL)
#endif
#ifdef FIELD_TYPE_GEOMETRY
		PDO_MYSQL_NATIVE_TYPE_NAME(GEOMETRY)
#endif
		PDO_MYSQL_NATIVE_TYPE_NAME(TIMESTAMP)
#ifdef FIELD_TYPE_YEAR
		PDO_MYSQL_NATIVE_TYPE_NAME(YEAR)
#endif
		PDO_MYSQL_NATIVE_TYPE_NAME(SET)
		PDO_MYSQL_NATIVE_TYPE_NAME(ENUM)
		PDO_MYSQL_NATIVE_TYPE_NAME(DATE)
#ifdef FIELD_TYPE_NEWDATE
		PDO_MYSQL_NATIVE_TYPE_NAME(NEWDATE)
#endif
		PDO_MYSQL_NATIVE_TYPE_NAME(TIME)
		PDO_MYSQL_NATIVE_TYPE_NAME(DATETIME)
		PDO_MYSQL_NATIVE_TYPE_NAME(TINY_BLOB)
		PDO_MYSQL_NATIVE_TYPE_NAME(MEDIUM_BLOB)
		PDO_MYSQL_NATIVE_TYPE_NAME(LONG_BLOB)
		PDO_MYSQL_NATIVE_TYPE_NAME(BLOB)
		PDO_MYSQL_NATIVE_TYPE_NAME(NULL)
		default:
			return NULL;
	}
#undef PDO_MYSQL_NATIVE_TYPE_NAME
} /* }}} */

static int pdo_mysql_stmt_col_meta(pdo_stmt_t *stmt, zend_long colno, zval *return_value) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
	const MYSQL_FIELD *F;
	zval flags;
	char *str;

	PDO_DBG_ENTER("pdo_mysql_stmt_col_meta");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
	if (!S->result) {
		PDO_DBG_RETURN(FAILURE);
	}
	if (colno >= stmt->column_count) {
		/* error invalid column */
		PDO_DBG_RETURN(FAILURE);
	}

	array_init(return_value);
	array_init(&flags);

	F = S->fields + colno;

	if (F->def) {
		add_assoc_string(return_value, "mysql:def", F->def);
	}
	if (IS_NOT_NULL(F->flags)) {
		add_next_index_string(&flags, "not_null");
	}
	if (IS_PRI_KEY(F->flags)) {
		add_next_index_string(&flags, "primary_key");
	}
	if (F->flags & MULTIPLE_KEY_FLAG) {
		add_next_index_string(&flags, "multiple_key");
	}
	if (F->flags & UNIQUE_KEY_FLAG) {
		add_next_index_string(&flags, "unique_key");
	}
	if (IS_BLOB(F->flags)) {
		add_next_index_string(&flags, "blob");
	}
	str = type_to_name_native(F->type);
	if (str) {
		add_assoc_string(return_value, "native_type", str);
	}

	enum pdo_param_type param_type;
	switch (F->type) {
		case MYSQL_TYPE_BIT:
		case MYSQL_TYPE_YEAR:
		case MYSQL_TYPE_TINY:
		case MYSQL_TYPE_SHORT:
		case MYSQL_TYPE_INT24:
		case MYSQL_TYPE_LONG:
#if SIZEOF_ZEND_LONG==8
		case MYSQL_TYPE_LONGLONG:
#endif
			param_type = PDO_PARAM_INT;
			break;
		default:
			param_type = PDO_PARAM_STR;
			break;
	}
	add_assoc_long(return_value, "pdo_type", param_type);

	add_assoc_zval(return_value, "flags", &flags);
	add_assoc_string(return_value, "table", (char *) (F->table?F->table : ""));

	PDO_DBG_RETURN(SUCCESS);
} /* }}} */

static int pdo_mysql_stmt_cursor_closer(pdo_stmt_t *stmt) /* {{{ */
{
	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;

	PDO_DBG_ENTER("pdo_mysql_stmt_cursor_closer");
	PDO_DBG_INF_FMT("stmt=%p", S->stmt);

	S->done = 1;
	pdo_mysql_free_result(S);
	if (S->stmt) {
		mysql_stmt_free_result(S->stmt);
	}

	while (mysql_more_results(S->H->server)) {
		MYSQL_RES *res;
		if (mysql_next_result(S->H->server) != 0) {
			pdo_mysql_error_stmt(stmt);
			PDO_DBG_RETURN(0);
		}
		res = mysql_store_result(S->H->server);
		if (res) {
			mysql_free_result(res);
		}
	}
	PDO_DBG_RETURN(1);
}
/* }}} */

const struct pdo_stmt_methods mysql_stmt_methods = {
	pdo_mysql_stmt_dtor,
	pdo_mysql_stmt_execute,
	pdo_mysql_stmt_fetch,
	pdo_mysql_stmt_describe,
	pdo_mysql_stmt_get_col,
	pdo_mysql_stmt_param_hook,
	NULL, /* set_attr */
	NULL, /* get_attr */
	pdo_mysql_stmt_col_meta,
	pdo_mysql_stmt_next_rowset,
	pdo_mysql_stmt_cursor_closer
};