Question

C# 实现多条件查询

string sqlStr = "select * from Houses where Hmoney between '" + min_money + "' and '" + max_money + "' and Harea between '" + max_area + "' and '" + min_area + "'";

不显示数据，，这句应该怎么改？

Answer 1

string sqlStr = string.Format(@"select * from Houses where Hmoney between '{0}' and '{1}' and Harea between '{2}' and '{3}'", min_money, max_money, min_area, max_area);

现改成这种写法，格式一目了然。另外，有一个问题，min_money, max_money, min_area, max_area都用单引号括起来了，这样会转变成字符串，在between..and里面用字符串？？？是你的本意吗？如果是数值之间的判断，要把单引号去掉！！

Answer 2

string sqlStr = "select * from Houses where Hmoney between '" + min_money + "' and '" + max_money + "' and Harea between '" + min_area + "' and '" + max_area + "'";
一般between前面放小的，后面放大的，你那样不知道行不行

追问

min的是小的，max的是大的，没错啊
而且 有一个between...and 的时候是有数据的 两个的时候就不行了

追答

你写的是
Harea between '" + max_area + "' and '" + min_area + "'";
我改了后
Harea between '" + min_area + "' and '" + max_area + "'";

Answer 3

2楼的君女子是个不错的建议,用string.Format确实是比你现在拼装好.
现在你可以用调试到sqlStr这个去数据库查就知道有没有数据了