PHP MySQL查询可能包含数据（如果存在）

Question

我当前的查询字符串是

    $var = '  fkMemberId = \'24\' AND month(DisallowTimeFrom) = \'10\' ';

毋庸置疑，如果表中没有十月，那么我得到一个空的结果。

我想要实现的目标是......

    $var = ' fkMemberId = \'24\' BUT MAY ALSO CONTAIN BUT IF NULL CONTINUE QUERY month(DisallowTimeFrom) = \'10\' ';

fkMemberId = \ '24 \'必须

月（DisallowTimeFrom）= \''\'\ n \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ t \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n \ n <

为了简洁，我遗漏了其余的查询。

Answer 1

$var = ' fkMemberId = \'24\' AND (DisallowTimeFrom IS NULL OR month(DisallowTimeFrom) = \'10\') ';