I am already programing for many year already now i faced a real strange issue
I have query which verify for duplicate id and tid
$query4=mysql_query("select id,tid from transactionlog where id='$result1[id]' and tid ='$result1[tid ]'") ;
$num=mysql_num_rows($query4);
if ($num == 0)
{
// case new . insert new raw here
}
The db i am using is fairly big over 500k raw , now the strange part is that this query sometime return num_rows 0 even when id and tid exist ,
this happen in about 1 time each few million queries ,
by the way i am using 5.6.35-log under windows (i need mysql old_password function that's why i am using older version ).
I know it is possible to setup id and tx as primary and unique , but i really want to know how come num_rows returning 0 while it should have 1 . is it know bug that i am missing ?
anyone faced similar issue ???