连接多个凡在LINQ的条款或替代和

问题描述

反正是有加入LINQ where子句作为OR？

  VAR整数=新[] {1，3，5 7}; 
 
 VAR的查询=从我在整数选择我; 
 
 =查询query.Where（Q =>问== 3）; 
 
 =查询query..Where（Q =>问== 7）; 
  

我要的是动态地添加where子句，但让他们使用或代替和

解决方案

如果你想留你的强类型的LINQ查询你应该看看LinqKit和谓语的建设。我已经使用这个类似的东西，发现它与和/或过滤器堆叠很好地工作。

检查出的获得更深入的信息。下面是从我的代码剪断：

  //设置初始谓词的obj然后堆在别人：
 basePredicate = basePredicate.And（p =>假）; 
 VAR predicate1 = PredicateBuilder.True<&人GT;（）; 
 
的foreach（在PARMS SearchParms PARM）
 {
开关（parm.field）
 {
案名字：
 predicate1 = predicate1.And（p值=> p.FirstName.Trim（）ToLower将（）包含（S值）。）; 
中断; 
 //等等...... 
} 
 
} 
 //运行基于您和/或PARM值的键来确定堆叠：
如果（Parm.isAnd）{
 basePredicate = basePredicate.And（predicate1）; 
}其他{
 basePredicate = basePredicate.Or（predicate1）; 
} 
  

Is there anyway to join LINQ where clauses as OR ?

var ints = new [] { 1, 3, 5, 7 };

var query = from i in ints select i;

query = query.Where (q => q == 3);

query = query..Where (q => q == 7);

What I want is the ability to dynamically add where clauses but make them use OR instead of AND

解决方案

If you want to stay with your strong-typing Linq queries you should look into LinqKit and predicate building. I have used this for something similar and found it to work well with And / Or stacking of filters.

Check out the C#4.0/3.0 in a Nutshell excerpt for more in depth info. Here is a snip from my code:

        //Setup the initial predicate obj then stack on others:
        basePredicate = basePredicate.And(p => false);
        var predicate1 = PredicateBuilder.True<Person>();

        foreach (SearchParms parm in parms)
        {
            switch (parm.field)
            {
                case "firstname":
                    predicate1 = predicate1.And(p => p.FirstName.Trim().ToLower().Contains(sValue));
                    break;
                //etc...
            }

        }
        //Run a switch based on your and/or parm value to determine stacking:
        if (Parm.isAnd) {
             basePredicate = basePredicate.And(predicate1);
        } else {
             basePredicate = basePredicate.Or(predicate1);
        }

这篇关于连接多个凡在LINQ的条款或替代和的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！