my_bool mysql_eof(MYSQL_RES *result)
20.4.10.1 Description
This function is deprecated. mysql_errno()
or mysql_error()
may be used instead.
mysql_eof()
determines whether or not the last row of a result
set has been read.
If you acquire a result set from a successful call to
mysql_store_result()
, the client receives the entire set in one
operation. In this case, a NULL
return from mysql_fetch_row()
always means the end of the result set has been reached and it is
unnecessary to call mysql_eof()
.
On the other hand, if you use mysql_use_result()
to initiate a result
set retrieval, the rows of the set are obtained from the server one by one as
you call mysql_fetch_row()
repeatedly. Because an error may occur on
the connection during this process, a NULL
return value from
mysql_fetch_row()
does not necessarily mean the end of the result set
was reached normally. In this case, you can use mysql_eof()
to
determine what happened. mysql_eof()
returns a non-zero value if the
end of the result set was reached and zero if an error occurred.
Historically, mysql_eof()
predates the standard MySQL error
functions mysql_errno()
and mysql_error()
. Since those error
functions provide the same information, their use is preferred over
mysql_eof()
, which is now deprecated. (In fact, they provide more
information, since mysql_eof()
returns only a boolean value whereas
the error functions indicate a reason for the error when one occurs.)
20.4.10.2 Return values
Zero if an error occurred. Non-zero if the end of the result set has been
reached.
20.4.10.3 Errors
None.
20.4.10.4 Example
The following example shows how you might use mysql_eof()
:
mysql_query(&mysql,"SELECT * FROM some_table");
result = mysql_use_result(&mysql);
while((row = mysql_fetch_row(result)))
{
// do something with data
}
if(!mysql_eof(result)) // mysql_fetch_row() failed due to an error
{
fprintf(stderr, "Error: %s\n", mysql_error(&mysql));
}
However, you can achieve the same effect with the standard MySQL
error functions:
mysql_query(&mysql,"SELECT * FROM some_table");
result = mysql_use_result(&mysql);
while((row = mysql_fetch_row(result)))
{
// do something with data
}
if(mysql_errno(&mysql)) // mysql_fetch_row() failed due to an error
{
fprintf(stderr, "Error: %s\n", mysql_error(&mysql));
}