How to check multiple times (within foreach) if values from three arrays exists in three mysql columns?
One way SELECT, fetch whole column and create array with the column values. Then (in_array($value_to_check[$i], $whole_mysql_column).
Other way would be multiple SELECT Column FROM Table WHERE Column = ? and ? is $value_to_check[$i]
Suppose both ways uses much resources. Is there better way?
SELECT... not good.editbelow the question, you may see initial long question, where I described all process.