Difference between revisions of "OpenDBX/C API/odbx field length"

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__NOTOC__
 
__NOTOC__
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'''Returns the length of a field value'''
  
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  unsigned long odbx_field_length(
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  #include <opendbx/api.h>
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    odbx_result_t* result,
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    unsigned long pos )
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= Description: =
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unsigned long '''odbx_field_length'''(
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    odbx_result_t* '''''result''''',
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    unsigned long '''''pos''''' )
  
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Returns the length of the field value specified by "pos" of the current row. The value of "pos" must be in the range from 0 to [[OpenDBX_column_count|odbx_column_count()]]-1.
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== Description ==
  
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= Parameters: =
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[[OpenDBX/API/odbx_field_length|odbx_field_length]]() returns the length of the field value in bytes. The field is part of the current row which was retrieved by the latest call to [[OpenDBX/API/odbx_row_fetch|odbx_row_fetch]]() and is specified by the column index given by '''''pos'''''.
  
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* result: Pointer to object created by [[OpenDBX_result|odbx_result()]]
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The '''''result''''' parameter required by this function must be a valid result set returned by [[OpenDBX/API/odbx_result|odbx_result]]() and must not has been feed to [[OpenDBX/API/odbx_result_finish|odbx_result_finish]]() before.
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* pos: Column number in the current result set
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= Return values: =
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Valid column indices for the requested column provided via '''''pos''''' start with zero and end with the value returned by [[OpenDBX/API/odbx_column_count|odbx_column_count]]() minus one.
  
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* Length of the value in the specified column of the current row
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== Return value ==
  
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= Errors: =
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The [[OpenDBX/API/odbx_field_length|odbx_field_length]]() function provides the number of bytes of the specified field to the caller. If the field value consists of character data, the returned length will be without the terminating zero character. For binary values the exact size of the block as stored in the database is returned.
  
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* None
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== Errors ==
  
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This function will also return zero if the '''''result''''' parameter is invalid or if the value of '''''pos''''' is out of range.
  
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----
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== See also ==
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Back to [[OpenDBX API|Overview]]
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* [[OpenDBX/API/odbx_field_value|odbx_field_value]]()
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* [[OpenDBX/API/odbx_result|odbx_result]]()

Latest revision as of 23:12, 28 April 2009

Returns the length of a field value 

#include <opendbx/api.h>

unsigned long odbx_field_length(
    odbx_result_t* result,
    unsigned long pos )

Description

odbx_field_length() returns the length of the field value in bytes. The field is part of the current row which was retrieved by the latest call to odbx_row_fetch() and is specified by the column index given by pos.

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.

Valid column indices for the requested column provided via pos start with zero and end with the value returned by odbx_column_count() minus one.

Return value

The odbx_field_length() function provides the number of bytes of the specified field to the caller. If the field value consists of character data, the returned length will be without the terminating zero character. For binary values the exact size of the block as stored in the database is returned.

Errors

This function will also return zero if the result parameter is invalid or if the value of pos is out of range.

See also

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