Question

运行查询后，我将结果输入到dataTable中，如下所示（这只是一个简化的结果集）：

food_cat    food
-----------------------
vegit       carrot
vegit       onion
vegit       tomato
fruit       cherry
fruit       banana
fruit       orange

我想在无序列表中列出按food_cat分组的结果。

<h3> Vegit </h3>
<ul>
    <li>carrot</li>
    <li>onion</li>
    <li>tomato</ti>
</ul>
<h3>fruit</h3>
<ul>
    <li>cherry</li>
    <li>banana</li>
    <li>orange</li>
</ul>

我尝试了一些for，if，while控制但无法找到一个好的解决方案。

Answer 1

因为你没有提供表名等，我会尽力给出答案。

string previous_food_cat = '';
bool firstEntrance = true

while(trace resultSet until no elements left) 
{
    if resultSet.food_cat != previous_food_cat //check if food_cat value changed
    {
        if (!firstEntrance) //if not first entrance close the <ul> tag before opening new one
        {
            print </ul>
        }

        print <h3> resultSet.food_cat </h3>  //open new <h3> tag
        print <ul>  //open new <ul> tag


        previous_food_cat = resultSet.food_cat  //update previous_food_cat for new food_cat value
        firstEntrance = false   //set firstEntrance false so that ul tqags should be closed
    }

    print <li> resultSet.food </li>
}

Answer 2

谢谢@zibidyum，你的技术让我找到了解决方案。但最终的解决方案是：

public bool firstcat; // defined at before Page_Load method
public int temp_cat;  // defined at before Page_Load method


for (int i = 0; i < dt.Rows.Count; i++)
{
    if (temp_cat != Convert.ToInt32(dt.Rows[i]["food_cat"]))
    {
        if (i > 0 && !firstcat)
            content.InnerHtml += "</ul>"; //solution's most critic point is here

        content.InnerHtml += "<ul>"
    }

    content.InnerHtml += String.Format("<li>{0}</li>", dt.Rows[i]["food"].ToString());

    temp_cat = Convert.ToInt32(dt.Rows[i]["food_cat"]);
}

欢迎任何更好的解决方案，建议和/或想法。

嵌套的SQL查询结果列表

2 个答案: