关于Lambda
2个Lambda怎么合并？
比如
query = data.Where(x => x.ID == 1);
query = query.Where(x => x.Name == "aaa");
[解决办法]
query = data.Where(x => x.ID == 1&&x.Name == "aaa");
[解决办法]
说清楚你的意思
如果是合并条件
var query = data.Where(x => x.ID == 1&&x.Name == "aaa");
如果是合并两个结果集，求并集嘛？？
如下
var query1 = data.Where(x => x.ID == 1);
var query2 = query.Where(x => x.Name == "aaa");
var query = query1.Union(query2);//query1 query2 结构一样
[解决办法]
class A
{
public int ID { get; set; }
public string Name { get; set; }
}
class Program
{
static void Main(string[] args)
{
var data = Enumerable.Repeat(0, 6).Select((x, i) => new A { ID = i / 2, Name = ((char)(i / 2 + 65)).ToString() });
Expression<Func<A, bool>> query1 = x => x.ID == 1;
Expression<Func<A, bool>> query2 = x => x.Name == "A";
var query = data.Where(Expression.Lambda(Expression.AndAlso((query1 as LambdaExpression).Body, (query2 as LambdaExpression).Body), (query1 as LambdaExpression).Parameters).Compile() as Func<A, bool>);
foreach (var item in query)
Console.WriteLine("{0} {1}", item.ID, item.Name);
}
}
