27.7.6.13 mysql_eof()
my_bool mysql_eof(MYSQL_RES *result)
This function is deprecated. mysql_errno()
or mysql_error()
may be used instead.
mysql_eof()
determines whether 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()
. When used with mysql_store_result()
, mysql_eof()
always returns true.
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 nonzero 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()
. Because those error functions provide the same information, their use is preferred over mysql_eof()
, which is deprecated. (In fact, they provide more information, because mysql_eof()
returns only a boolean value whereas the error functions indicate a reason for the error when one occurs.)
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));
}