在MySQL数据库的编辑器中用语句SELECT MIN(IntervalRead) FROM flowmeter WHERE CollectorId=5;
得到flowmeter表中在CollectorId=5条件下IntervalRead字段的最小值10我的问题是在VC中如何实现?函数是什么?
我的想法:
MYSQL *m_conn;
CString s_sql;
....
s_sql="SELECT MIN(IntervalRead) FROM flowmeter WHERE CollectorId=5";
mysql_real_query(m_conn,(char*)(LPCTSTR)s_sql,(UINT)s_sql.GetLength());那结果保存在哪里?怎么读取这个结果?
请教专家 谢了~
得到flowmeter表中在CollectorId=5条件下IntervalRead字段的最小值10我的问题是在VC中如何实现?函数是什么?
我的想法:
MYSQL *m_conn;
CString s_sql;
....
s_sql="SELECT MIN(IntervalRead) FROM flowmeter WHERE CollectorId=5";
mysql_real_query(m_conn,(char*)(LPCTSTR)s_sql,(UINT)s_sql.GetLength());那结果保存在哪里?怎么读取这个结果?
请教专家 谢了~
result = mysql_use_result(&mysql);
while((row = mysql_fetch_row(result)))
{
printf(row[0]);
}
if(!mysql_eof(result)) // mysql_fetch_row() failed due to an error
{
fprintf(stderr, "Error: %s\n", mysql_error(&mysql));
}
char str[512];
int cnt = 0;
sprintf(str,"select count(*) as cnt from %s", tmpTableName); mysql_real_query(mysql_, str, strlen(str));
result_ = mysql_store_result(mysql_);
while (row_ = mysql_fetch_row(result_))
{
// get the field value
if (row_[0])
{
std::cout<<"count = "<<row_[0]<<std::endl;
// convert it into int
cnt = atoi(row_[0]);
std::cout<<"cnt value = "<<row_[0]<<std::endl;
}
} mysql_free_result(result_);