OpenDBX/C API/odbx column count

From Linuxnetworks
Jump to: navigation, search

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_finish() 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