mysql_field_count() - 0
Returns the number of columns for the most recent query on the
connection.The normal use of this function is when
mysql_store_result() returned
NULL (and thus you have no result set
pointer). In this case, you can call
mysql_field_count() to determine
whether mysql_store_result()
should have produced a nonempty result. This enables the client
program to take proper action without knowing whether the query
was a SELECT (or
SELECT-like) statement. The
example shown here illustrates how this may be done.mysql_store_result()mysql_store_result()NULLmysql_field_count()mysql_field_count()mysql_store_result()mysql_store_result()SELECTSELECTSELECTSELECTSee Section 25.8.15.1, “Why mysql_store_result() Sometimes Returns NULL After mysql_query()
Returns Success”.Section 25.8.15.1, “Why mysql_store_result() Sometimes Returns NULL After mysql_query()
Returns Success”
Syntax
unsigned int mysql_field_count(MYSQL *mysql)
Example
MYSQL_RES *result;
unsigned int num_fields;
unsigned int num_rows;
if (mysql_query(&mysql,query_string))
{
// error
}
else // query succeeded, process any data returned by it
{
result = mysql_store_result(&mysql);
if (result) // there are rows
{
num_fields = mysql_num_fields(result);
// retrieve rows, then call mysql_free_result(result)
}
else // mysql_store_result() returned nothing; should it have?
{
if(mysql_field_count(&mysql) == 0)
{
// query does not return data
// (it was not a SELECT)
num_rows = mysql_affected_rows(&mysql);
}
else // mysql_store_result() should have returned data
{
fprintf(stderr, "Error: %s\n", mysql_error(&mysql));
}
}
}
Output / Return Value
An unsigned integer representing the number of columns in a
result set.
Limitations
Alternatives / See Also
Reference