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我需要一些关于邻近搜索的帮助。我需要在房地产数据库上运行一个 select 语句，以确定最接近搜索条件的顶部行（用户输入的数字）。然后我需要在 gridview 控件中显示这些值。

我不知道如何添加多个计算列的值以创建具有接近结果的最后一列。

有人可以帮我弄清楚如何将多个计算列汇总为一列，然后按此列分组吗？

以下是我尝试过的代码，但出现错误异常。

aQueryString = "SELECT Top " + txtNumRows.Text;
aQueryString += "propno, ";

if (txtMaxAsk.Text != "")
    aQueryString += "askprice, ";

aQueryString += "sqr(((askprice - " + txtMaxAsk.Text;
aQueryString += ")/1000000)^2) AS m1,";

if (txtMinSqFt.Text != "")
    aQueryString += "sqft, ";

aQueryString += "sqr(((sqft - " + txtMinSqFt.Text;
aQueryString += ")/6000)^2) AS m2 ";
aQueryString += "sum(m1) + sum(m2) FROM property ORDER BY 4 ";

anAccessCommand = anAccessConnection.CreateCommand();
anAccessCommand.CommandText = aQueryString;
gvProperty.DataSource = anAccessCommand.CommandText;
anAccessReader = anAccessCommand.ExecuteReader();
gvProperty.DataSource = anAccessReader;
gvProperty.Visible = true;

try
{
    gvProperty.DataBind();
}
catch (Exception ex)
{
    Response.Write("Binding exception in Button1_Click<BR>");
    Response.Write("Access Exception Handler: {0} " + ex.ToString());
}

这是我得到的 OleDbException：

The SELECT statement includes a reserved word or an argument name that is misspelled or missing, or the punctuation is incorrect.

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1 回答 1

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您在此行末尾缺少一个逗号：

aQueryString += ")/6000)^2) AS m2 ";

更正：

aQueryString += ")/6000)^2) AS m2, ";
于 2013-11-02T01:42:05.263 回答