所以我有這個代碼檢查4個參數(作者,標題,關鍵字和主題)爲我正在進行的項目做一些動態sql查詢生成,我只是想知道是否有人知道更好的方法寫出來。我感覺這是一種非常低效的方式,但這樣做很晚,而且我很累。請讓我知道,如果你知道有更好的方法來做到這一點,那麼這裏只是一堆if/else case檢查語句。有沒有更好的方法來寫這個?檢查場景
謝謝!
if(_author!=null)
{
query += authorQ;
if(_title != null)
{
if(conjunct[0] == 0)
{
query += " AND ";
query += titleQ;
}
else
{
query += " OR ";
query += titleQ;
}
if(_keyword != null)
{
if(conjunct[1] == 0)
{
query += " AND ";
query += keywordQ;
}
else
{
query += " OR ";
query += keywordQ;
}
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
else
{
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
}//title = null
else
{
if(_keyword != null)
{
if(conjunct[1] == 0)
{
query += " AND ";
query += keywordQ;
}
else
{
query += " OR ";
query += keywordQ;
}
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
else //keyword null
{
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
//if subject's null at this point we don't care
}
}
}
else //author null
{
if(_title != null)
{
if(conjunct[0] == 0)
{
query += " AND ";
query += titleQ;
}
else
{
query += " OR ";
query += titleQ;
}
if(_keyword != null)
{
if(conjunct[1] == 0)
{
query += " AND ";
query += keywordQ;
}
else
{
query += " OR ";
query += keywordQ;
}
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
else
{
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
}//title = null
else
{
if(_keyword != null)
{
if(conjunct[1] == 0)
{
query += " AND ";
query += keywordQ;
}
else
{
query += " OR ";
query += keywordQ;
}
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
}
else //keyword null
{
if(_subject != null)
{
if(conjunct[2] == 0)
{
query += " AND ";
query += subjectQ;
}
else
{
query += " OR ";
query += subjectQ;
}
}
//if subject's null at this point we don't care
}
}
}
您可以查詢+ = variableName;在if語句中,你可以使用三元運算符:例如: - query + =(conjunct [0] == 0?「AND」:「OR」); query + = titleQ; – 2012-03-17 07:34:33
我知道一個非常棒的方式,'但它晚了,我很累';) – DaveFar 2012-03-17 11:44:57
此外,很多代碼是「死」,即無法訪問,只需將其放入最新版本的eclipse中,並啓用所有警告。 。 – Adam 2012-03-17 11:53:00