Question

客户是T-SQL DB(我没有控制,因此可能不会改变)类型“文字”的一个领域。

我这样说:

List<string> compare = new List<string>();
compare.Add("one");
compare.Add("two");

var q = from t in customer
        where t.text.Contains( compare.First())
        select t;

这将发挥作用。

但现在我想做的是: NOT WorkingING!

var q = from t in customer
        where compare.Contains( t.text )
        select t;

我如何能够做到这一点? 是否可能?

EDIT:问题显然不清楚: 不能用“=”来提一下KQ中的案文一栏,而只能用LKE。相比之下。内容(t.text)将产生错误,因为它被转换成一个使用“=”的查询。

What I did not tell - I thought it is irrelevant - is, that I use LINQ-to-ORM (LLBLGen in this case). What I tried instead:

var q = from t in customer
        where compare.Any( x => t.text.Contains(x) )
        select t;

既然如此,也就不起作用。目前,我不工作,但例外情况是,不能够转换成《限制令》。

我希望这能澄清一些问题。

EDIT:

Joseph pointed this out to me: PredicateBuilder. It creates an Expression on a given ObjectType. Now my problem is, that my type is an anonymous type out of multiple joins. Is there an easy or elegant way to handle this?

Answer 1

现在我可能失踪,但你的法典认为它应该发挥作用。你们是否包括档案顶点的名称空间?

using System.Linq;
using System.Linq.Expressions;

你们也可以在没有Linq2Sql syntax的情况下改写:

var q = customer.Where(c => compare.Contains(c.text));

Answer 2

您可以利用LinqKit的自由前线建筑商班进行问询。这里是一个博客员额,介绍其使用情况,并与下载网站链接。

http://thecodeslinger.wordpress.com/2008/10/28/linqkit-predicatebuildert-goodness/

下面是员额的编码样本。

    //First get a list of keywords that match the description entered.
                string[] parts = txtInclude.Text.Split(new[] {‘ ‘});
                string[] noparts = null;
                if(txtButNot.Text.Trim().Length > 0)
                    noparts = txtExclude.Text.Trim().Split(new[] {‘ ‘});

                var pred = PredicateBuilder.True<Pet>();
   //here is where you would loop through your compare object
                parts.ForEach(p => pred = pred.And(pl => pl.description.Contains(p)));
                if(noparts != null)
                    noparts.ForEach(p => pred = pred.And(pl => !pl.description.Contains(p)));

                var pets = from s in db.Pets.Where(pred)
                        select s;

Answer 3

你们必须把案文领域改为说明

        var query = from t in dataContext.table
                    where compare.Contains(t.textField.ToString())
                    select t;

友情链接