C# 在Where子句的lambda表达式中使用if/else

我有这个搜索代码

public List<Tbl_Product> ProductSearch(DateTime startdate, DateTime enddate, string productname, int suply)
{
    var q = _db.Tbl_Product
            .Where(model => 
                model.DateReg == startdate && 
                model.DateReg == enddate)
            .Where(model => 
                model.ProductName.Contains(productname))
            .Where({});

}

---

我应该怎么做？

我个人不会在Where子句中这样做，因为这意味着您正在将suply变量传递到数据库

var q = _db.Tbl_Product
    .Where(model => model.DateReg == startdate 
                 && model.DateReg == enddate
                 && model.ProductName.Contains(productname));

if(suply == 1)
{
    q = q.Where(model => model.Suply > 0);
}
else
{
    q = q.Where(model => model.Suply == 0);
}

然而，如果你真的坚持要一次完成这一切：

.Where(model => (suply == 1 && model.Suply > 0)
             || (suply != 1 && model.Suply == 0));

可能重复的

.Where(model => (suply == 1 && model.Suply > 0)
             || (suply != 1 && model.Suply == 0));