Difference between revisions of "OpenDBX/C API/odbx column count"

From Linuxnetworks
< OpenDBX‎ | C API
Jump to: navigation, search
(Fixed return type.)
(Talk)
(docbook2x update)
Line 2: Line 2:
 
'''Get the number of columns in the current result set'''
 
'''Get the number of columns in the current result set'''
  
  #include <odbx.h>
+
  #include <opendbx/api.h>
+
 
  unsigned long '''odbx_column_count'''(
+
  int '''odbx_column_count'''(
 
     odbx_result_t* '''''result''''' )
 
     odbx_result_t* '''''result''''' )
  
Line 26: Line 26:
 
* [[OpenDBX/API/odbx_column_type|odbx_column_type]]()
 
* [[OpenDBX/API/odbx_column_type|odbx_column_type]]()
 
* [[OpenDBX/API/odbx_result|odbx_result]]()
 
* [[OpenDBX/API/odbx_result|odbx_result]]()
 
----
 
Back to [[OpenDBX/API|Overview]]
 

Revision as of 00:33, 24 May 2008

Get the number of columns in the current result set

#include <opendbx/api.h>
int odbx_column_count(
    odbx_result_t* result )

Description

Returns the number of columns which belongs to the current result set allocated by odbx_result(). The number will never change within a result set with one notable exception: MySQL returns all outstanding rows of a previous result set first if they were not fetched completely by odbx_row_fetch() before. Therefore, the column count might change in this special situation. It is strongly advised to fetch all rows of a result set before calling odbx_result() again because other backends will return an error in this case.

The result parameter required by this function must be a valid result set returned by odbx_result() and must not has been feed to odbx_result_free() before.

Return value

odbx_column_count() returns the number of columns/fields which are available in the current result set. The value depends on the column list being part of the SELECT query and it is zero if the query wasn't a SELECT-like query.

Errors

This function will also return zero if the result parameter is invalid.

See also