php man page for odbc_num_rows

ODBC_NUM_ROWS(3)							 1							  ODBC_NUM_ROWS(3)

odbc_num_rows - Number of rows in a result

SYNOPSIS
       int odbc_num_rows (resource  $result_id)

DESCRIPTION
	Gets  the number of rows in a result. For INSERT, UPDATE and DELETE statements odbc_num_rows(3) returns the number of rows affected. For a
       SELECT clause this can be the number of rows available.

PARAMETERS
	      o $result_id
		- The result identifier returned by odbc_exec(3).

RETURN VALUES
	Returns the number of rows in an ODBC result. This function will return -1 on error.

NOTES
       Note

	       Using odbc_num_rows(3) to determine the number of rows available after a SELECT will return -1 with many drivers.

PHP Documentation Group 													  ODBC_NUM_ROWS(3)