C# SQL语句中带有2个条件的WHERE子句

我有以下aspx（html）代码：

---

SQL中存在语法错误；而不是：

query = "select * from customer where country = '" + country + "select * from customer where idcurrency = '" + idcurrency + "'";

它应该如下所示：

query = "select * from customer where country = '" + country + "' AND idcurrency = '" + idcurrency + "'";

---

希望这会有所帮助。

根据您当前的代码，无论您是否选择货币，在选择国家/地区时，都将始终执行下面的第一个

if

块

if (country != "select")
{
    query = "select * from customer where country = '" + country + "'";
}

您还需要在第一个

if

块中检查所选货币。我还修复了错误的SQL语法

if (country != "select")
{
    if (idcurrency != "selected")
    {
        query = "select * from customer where country = '" + country + "' and idcurrency = '" + idcurrency + "'";
    }
    else
    {
        query = "select * from customer where country = '" + country + "'";
    }
}

---

我们无法为您调试所以投票关闭哦！这只是搜索客户文本框的一个条件，先生，获取客户的值，我获取文本框id=“search”的值并将其放入字符串customer=（this.search.value）；不客气！我很高兴它能为您服务。请检查已接受的答案，如果您还有更多问题，请单独发布。祝您项目顺利。致以问候，这项工作，先生，非常感谢！：）一个问题：如果我的国家和货币与其数据库不匹配，我应该将警报标签放在哪里？

query = "select * from customer where country = '" + country + "' AND idcurrency = '" + idcurrency + "'";

if (country != "select")
{
    query = "select * from customer where country = '" + country + "'";
}

if (country != "select")
{
    if (idcurrency != "selected")
    {
        query = "select * from customer where country = '" + country + "' and idcurrency = '" + idcurrency + "'";
    }
    else
    {
        query = "select * from customer where country = '" + country + "'";
    }
}