dblib.c

在Linux/Unix下面访问WINDOWS SQLSERVER 的ODBC驱动程序

	TDS_MUTEX_UNLOCK(&dblib_mutex);

	dblib_release_tds_ctx(count);
}

static const char *
prdbresults_state(int retcode)
{
	static char unknown[12]="oops: ";
	switch(retcode) {
	case _DB_RES_INIT:		return "_DB_RES_INIT";
	case _DB_RES_RESULTSET_EMPTY:	return "_DB_RES_RESULTSET_EMPTY";
	case _DB_RES_RESULTSET_ROWS:	return "_DB_RES_RESULTSET_ROWS";
	case _DB_RES_NEXT_RESULT:	return "_DB_RES_NEXT_RESULT";
	case _DB_RES_NO_MORE_RESULTS:	return "_DB_RES_NO_MORE_RESULTS";
	case _DB_RES_SUCCEED:		return "_DB_RES_SUCCEED";
	default:
		sprintf(unknown + 6, "%u ??", retcode);
	}
	return unknown;
}

static const char *
prdbretcode(int retcode)
{
	static char unknown[12]="oops: ";
	switch(retcode) {
	case REG_ROW:		return "REG_ROW/MORE_ROWS";
	case NO_MORE_ROWS:	return "NO_MORE_ROWS";
	case BUF_FULL:		return "BUF_FULL";
	case NO_MORE_RESULTS:	return "NO_MORE_RESULTS";
	case SUCCEED:		return "SUCCEED";
	case FAIL:		return "FAIL";
	default:
		sprintf(unknown + 6, "%u ??", retcode);
	}
	return unknown;
}

static const char *
prretcode(int retcode)
{
	static char unknown[12]="oops";
	switch(retcode) {
	case TDS_SUCCEED:		return "TDS_SUCCEED";
	case TDS_FAIL:			return "TDS_FAIL";
	case TDS_NO_MORE_RESULTS:	return "TDS_NO_MORE_RESULTS";
	case TDS_CANCELLED:		return "TDS_CANCELLED";
	default:
		sprintf(unknown, "%u ??", retcode);
	}
	return unknown;
}

static const char *
prresult_type(int result_type)
{
	static char unknown[12]="oops";
	switch(result_type) {
	case TDS_ROW_RESULT:		return "TDS_ROW_RESULT";
	case TDS_PARAM_RESULT:		return "TDS_PARAM_RESULT";
	case TDS_STATUS_RESULT:		return "TDS_STATUS_RESULT";
	case TDS_MSG_RESULT:		return "TDS_MSG_RESULT";
	case TDS_COMPUTE_RESULT:	return "TDS_COMPUTE_RESULT";
	case TDS_CMD_DONE:		return "TDS_CMD_DONE";
	case TDS_CMD_SUCCEED:		return "TDS_CMD_SUCCEED";
	case TDS_CMD_FAIL:		return "TDS_CMD_FAIL";
	case TDS_ROWFMT_RESULT:		return "TDS_ROWFMT_RESULT";
	case TDS_COMPUTEFMT_RESULT:	return "TDS_COMPUTEFMT_RESULT";
	case TDS_DESCRIBE_RESULT:	return "TDS_DESCRIBE_RESULT";
	case TDS_DONE_RESULT:		return "TDS_DONE_RESULT";
	case TDS_DONEPROC_RESULT:	return "TDS_DONEPROC_RESULT";
	case TDS_DONEINPROC_RESULT:	return "TDS_DONEINPROC_RESULT";
	case TDS_OTHERS_RESULT:		return "TDS_OTHERS_RESULT";
	default:
		sprintf(unknown, "%u ??", result_type);
	}
	return unknown;
}

/**
 * \ingroup dblib_core
 * \brief Set up query results.  
 *
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \retval SUCCEED Some results are available.
 * \retval FAIL query was not processed successfully by the server
 * \retval NO_MORE_RESULTS query produced no results. 
 *
 * \remarks Call dbresults() after calling dbsqlexec() or dbsqlok(), or dbrpcsend() returns SUCCEED.  Unless
 *	one of them fails, dbresults will return either SUCCEED or NO_MORE_RESULTS.  
 *
 *	The meaning of \em results is very specific and not very intuitive.  Results are created by either
 *	- a SELECT statement
 * 	- a stored procedure
 *
 * 	When dbresults returns SUCCEED, therefore, it indicates the server processed the query successfully and 
 * 	that one or more of these is present:
 *	- metadata -- dbnumcols() returns 1 or more
 *	- data -- dbnextrow() returns SUCCEED
 *	- return status -- dbhasretstat() returns TRUE
 *	- output parameters -- dbnumrets() returns 1 or more
 *
 *	If none of the above are present, dbresults() returns NO_MORE_RESULTS.  
 * 	
 * 	SUCCEED does not imply that DBROWS() will return TRUE or even that dbnumcols() will return nonzero.  
 *	A general algorithm for reading results will call dbresults() until it return NO_MORE_RESULTS (or FAIL).  
 * 	An application should check for all the above kinds of results within the dbresults() loop.  
 * 
 * \sa dbsqlexec(), dbsqlok(), dbrpcsend(), dbcancel(), DBROWS(), dbnextrow(), dbnumcols(), dbhasretstat(), dbretstatus(), dbnumrets()
 */
RETCODE
dbresults(DBPROCESS * dbproc)
{
	RETCODE erc = _dbresults(dbproc);
	tdsdump_log(TDS_DBG_FUNC, "dbresults returning %d (%s)\n", erc, prdbretcode(erc));
	return erc;
}

static RETCODE
_dbresults(DBPROCESS * dbproc)
{
	RETCODE retcode = FAIL;
	TDSSOCKET *tds;
	int result_type;
	int done_flags;

	tdsdump_log(TDS_DBG_FUNC, "dbresults(%p)\n", dbproc);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);

	tds = dbproc->tds_socket;

	if (IS_TDSDEAD(tds))
		return FAIL;

	tdsdump_log(TDS_DBG_FUNC, "dbresults: dbresults_state is %d (%s)\n", 
					dbproc->dbresults_state, prdbresults_state(dbproc->dbresults_state));
	switch ( dbproc->dbresults_state ) {

	case _DB_RES_SUCCEED:
		dbproc->dbresults_state = _DB_RES_NEXT_RESULT;
		return SUCCEED;
		break;
	case _DB_RES_RESULTSET_ROWS:
		dbperror(dbproc, SYBERPND, 0); /* dbresults called while rows outstanding.... */
		return FAIL;
		break;
	case _DB_RES_NO_MORE_RESULTS:
		return NO_MORE_RESULTS;
		break;
	default:
		break;
	}

	for (;;) {
		retcode = tds_process_tokens(tds, &result_type, &done_flags, TDS_TOKEN_RESULTS);

		tdsdump_log(TDS_DBG_FUNC, "dbresults() tds_process_tokens returned %d (%s),\n\t\t\tresult_type %s\n", 
						retcode, prretcode(retcode), prresult_type(result_type));

		switch (retcode) {

		case TDS_SUCCEED:

			switch (result_type) {
	
			case TDS_ROWFMT_RESULT:
				buffer_free(&dbproc->row_buf);
				buffer_alloc(dbproc);
				dbproc->dbresults_state = _DB_RES_RESULTSET_EMPTY;
				break;
	
			case TDS_COMPUTEFMT_RESULT:
				break;
	
			case TDS_ROW_RESULT:
			case TDS_COMPUTE_RESULT:
	
				dbproc->dbresults_state = _DB_RES_RESULTSET_ROWS;
				return SUCCEED;
				break;
	
			case TDS_DONE_RESULT:
			case TDS_DONEPROC_RESULT:
				tdsdump_log(TDS_DBG_FUNC, "dbresults(): dbresults_state is %d (%s)\n", 
						dbproc->dbresults_state, prdbresults_state(dbproc->dbresults_state));

				/* A done token signifies the end of a logical command.
				 * There are three possibilities:
				 * 1. Simple command with no result set, i.e. update, delete, insert
				 * 2. Command with result set but no rows
				 * 3. Command with result set and rows
				 */
				switch (dbproc->dbresults_state) {

				case _DB_RES_INIT:
				case _DB_RES_NEXT_RESULT:
					dbproc->dbresults_state = _DB_RES_NEXT_RESULT;
					if (done_flags & TDS_DONE_ERROR)
						return FAIL;
					break;

				case _DB_RES_RESULTSET_EMPTY:
				case _DB_RES_RESULTSET_ROWS:
					dbproc->dbresults_state = _DB_RES_NEXT_RESULT;
					return SUCCEED;
					break;
				default:
					assert(0);
					break;
				}
				

			case TDS_DONEINPROC_RESULT:
				/* 
				 * Return SUCCEED on a command within a stored procedure
				 * only if the command returned a result set. 
				 */
				switch (dbproc->dbresults_state) {
				case _DB_RES_INIT:  
				case _DB_RES_NEXT_RESULT: 
					dbproc->dbresults_state = _DB_RES_NEXT_RESULT;
					break;
				case _DB_RES_RESULTSET_EMPTY :
				case _DB_RES_RESULTSET_ROWS : 
					dbproc->dbresults_state = _DB_RES_NEXT_RESULT;
					return SUCCEED;
					break;
				}
				break;

			case TDS_STATUS_RESULT:
			case TDS_MSG_RESULT:
			case TDS_DESCRIBE_RESULT:
			case TDS_PARAM_RESULT:
			default:
				break;
			}

			break;

		case TDS_NO_MORE_RESULTS:
			dbproc->dbresults_state = _DB_RES_NO_MORE_RESULTS;
			return NO_MORE_RESULTS;
			break;

		case TDS_CANCELLED:
		case TDS_FAIL:
			dbproc->dbresults_state = _DB_RES_INIT;
			return FAIL;
			break;
			
		default:
			tdsdump_log(TDS_DBG_FUNC, "dbresults() does not recognize return code from process_result_tokens\n");
			assert(0);
			return FAIL;
			break;
		}
	}
}


/**
 * \ingroup dblib_core
 * \brief Return number of regular columns in a result set.  
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \sa dbcollen(), dbcolname(), dbnumalts().
 */
int
dbnumcols(DBPROCESS * dbproc)
{
	tdsdump_log(TDS_DBG_FUNC, "dbnumcols(%p)\n", dbproc);
	CHECK_PARAMETER(dbproc, SYBENULL, 0);

	if (dbproc && dbproc->tds_socket && dbproc->tds_socket->res_info)
		return dbproc->tds_socket->res_info->num_cols;
	return 0;
}

/**
 * \ingroup dblib_core
 * \brief Return name of a regular result column.
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param column Nth in the result set, starting with 1.  
 * \return pointer to ASCII null-terminated string, the name of the column. 
 * \retval NULL \a column is not in range.
 * \sa dbcollen(), dbcoltype(), dbdata(), dbdatlen(), dbnumcols().
 * \bug Relies on ASCII column names, post iconv conversion.  
 *      Will not work as described for UTF-8 or UCS-2 clients.  
 *      But maybe it shouldn't.  
 */
char *
dbcolname(DBPROCESS * dbproc, int column)
{
	TDSCOLUMN *colinfo;
	
	tdsdump_log(TDS_DBG_FUNC, "dbcolname(%p, %d)\n", dbproc, column);

	colinfo = dbcolptr(dbproc, column);
	if (!colinfo)
		return NULL;
		
	assert(colinfo->column_name[colinfo->column_namelen] == 0);
	return colinfo->column_name;
}

/**
 * \ingroup dblib_core
 * \brief Read a row from the row buffer.
 * 
 * When row buffering is enabled (DBBUFFER option is on), the client can use dbgetrow() to re-read a row previously fetched 
 * with dbnextrow().  The effect is to move the row pointer -- analogous to fseek() -- back to \a row.  
 * Calls to dbnextrow() read from \a row + 1 until the buffer is exhausted, at which point it resumes
 * its normal behavior, except that as each row is fetched from the server, it is added to the row
 * buffer (in addition to being returned to the client).  When the buffer is filled, dbnextrow()  returns 
 * \c FAIL until the buffer is at least partially emptied with dbclrbuf().
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param row Nth row to read, starting with 1.
 * \retval REG_ROW returned row is a regular row.
 * \returns computeid when returned row is a compute row.
 * \retval NO_MORE_ROWS no such row in the row buffer.  Current row is unchanged.
 * \retval FAIL unsuccessful; row buffer may be full.  
 * \sa dbaltbind(), dbbind(), dbclrbuf(), DBCURROW(), DBFIRSTROW(), DBLASTROW(), dbnextrow(), dbsetrow().
 */
RETCODE
dbgetrow(DBPROCESS * dbproc, DBINT row)
{
	RETCODE result = FAIL;
	const int idx = buffer_row2idx(&dbproc->row_buf, row);

	tdsdump_log(TDS_DBG_FUNC, "dbgetrow(%p, %d)\n", dbproc, row);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);

	if (-1 == idx)
		return NO_MORE_ROWS;

	dbproc->row_buf.current = idx;
	buffer_transfer_bound_data(&dbproc->row_buf, TDS_ROW_RESULT, 0, dbproc, idx);
	result = REG_ROW;

	return result;
}

/**
 * \ingroup dblib_core
 * \brief Define substitution values to be used when binding null values.
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param bindtype	type of binding to which the substitute value will apply. 
 * \param bindlen 	size of the substitute value you are supplying, in bytes. 
 * 			Ignored except for CHARBIND and BINARYBIND. 
 * \param bindval 	pointer to a buffer containing the substitute value.
 * \retval SUCCEED query was processed without errors.
 * \retval FAIL query was not processed
 * \sa dbaltbind(), dbbind(), dbconvert(), dbnullbind().
 */
RETCODE
dbsetnull(DBPROCESS * dbproc, int bindtype, int bindlen, BYTE *bindval)
{
	BYTE *pval;
	
	tdsdump_log(TDS_DBG_FUNC, "dbsetnull(%p, %d, %d, %p)\n", dbproc, bindtype, bindlen, bindval);
	
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);
	CHECK_PARAMETER(bindval, SYBENBVP, FAIL);
	
	switch (bindtype) {
	case DATETIMEBIND:
	case DECIMALBIND:
	case FLT8BIND:
	case INTBIND:
	case MONEYBIND:
	case NUMERICBIND:
	case REALBIND:
	case SMALLBIND:
	case SMALLDATETIMEBIND:
	case SMALLMONEYBIND:
	case TINYBIND:
		bindlen = default_null_representations[bindtype].len;
		break;

	case CHARBIND:
	case BINARYBIND:
		CHECK_PARAMETER(bindlen >= 0, SYBEBBL, FAIL);
		break;
		
	case NTBSTRINGBIND:	bindlen = strlen((char *) bindval);
		break;
	case STRINGBIND:	bindlen = strlen((char *) bindval);
		break;
	case VARYBINBIND:	bindlen = ((TDS_VARBINARY*) bindval)->len;
		break;
	case VARYCHARBIND:	bindlen = ((TDS_VARCHAR*) bindval)->len;
		break;

#if 0
	case SENSITIVITYBIND:
	case BOUNDARYBIND:
#endif
	default:
		dbperror(dbproc, SYBEBTYP, 0);
		return FAIL;
	}

	if ((pval = malloc(bindlen)) == NULL) {
		dbperror(dbproc, SYBEMEM, errno);
		return FAIL;
	}
	
	/* free any prior allocation */
	if (dbproc->nullreps[bindtype].bindval != default_null_representations[bindtype].bindval)
		free((BYTE*)dbproc->nullreps[bindtype].bindval);

	memcpy(pval, bindval, bindlen);
	
	dbproc->nullreps[bindtype].bindval = pval;
	dbproc->nullreps[bindtype].len = bindlen;

	tdsdump_dump_buf(TDS_DBG_NETWORK, "null representation set ", pval,  bindlen);
	return SUCCEED;
}

/**
 * \ingroup dblib_core
 * \brief Make a buffered row "current" without fetching it into bound variables.  
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \retval MORE_ROWS row found
 * \retval NO_MORE_ROWS row not found
 * \retval FAIL \a dbproc is dead or not enabled
 * \sa dbaltbind(), dbbind(), dbcanquery(), dbclrbuf(), dbgetrow(), dbnextrow(), dbprrow().
 */
RETCODE
dbsetrow(DBPROCESS * dbproc, DBINT row)
{
	const int idx = buffer_row2idx(&dbproc->row_buf, row);

	tdsdump_log(TDS_DBG_FUNC, "dbsetrow(%p, %d)\n", dbproc, row);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);

	if (-1 == idx)
		return NO_MORE_ROWS;
		
	dbproc->row_buf.current = idx;
		
	/* FIXME: should determine REG_ROW or compute_id; */
	return REG_ROW;	
}

/**
 * \ingroup dblib_core
 * \brief Read result row into the row buffer and into any bound host variables.
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \retval REG_ROW regular row has been read.
 * \returns computeid when a compute row is read. 
 * \retval BUF_FULL reading next row would cause the buffer to be exceeded (and buffering is turned on).
 * No row was read from the server
 * \sa dbaltbind(), dbbind(), dbcanquery(), dbclrbuf(), dbgetrow(), dbprrow(), dbsetrow().
 */
RETCODE
dbnextrow(DBPROCESS * dbproc)
{
	TDSRESULTINFO *resinfo;
	TDSSOCKET *tds;
	RETCODE result = FAIL;
	TDS_INT res_type;
	TDS_INT computeid;
	int idx; /* row buffer index.  Unless DBUFFER is on, idx will always be 0. */

	tdsdump_log(TDS_DBG_FUNC, "dbnextrow(%p)\n", dbproc);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);

	tds = dbproc->tds_socket;
	if (IS_TDSDEAD(tds)) {
		dbperror(dbproc, SYBEDDNE, 0);
		return FAIL;
	}

	resinfo = tds->res_info;