C#表达式返回TSQL Contains关键字

我有以下代码：

public Expression FilterString(string property,string Value,ParameterExpression parameter)
{
    var getname = Expression.Property(parameter,property);

    var toLower = Expression.Call(getname,"ToLower",null,null);

    var contains = Expression.Call(toLower,"Contains",new[] { Expression.Constant(Value.ToString().ToLower()) });

    //This will result in "LOWER(Body) LIKE '%abc123% " but I need "CONTAINS(Body,'abc123')"

    return contains;
}

var parameter = Expression.Parameter(typeof(Message),"message");
var expressionFilter = myclass.FilterString("Body","abc123",parameter);
var lambda = Expression.Lambda(expressionFilter,parameter);

//Apply lambda to EF query object
query = query.Where((Expression<Func<Message,bool>>)lambda);

这会生成一个Tsql LIKE语句,但我希望它能够执行CONTAINS语句.

反正我是否可以修改上面的FilterString方法来实现它呢？

解决方法

它看起来不像你可以使用香草EF,至少根据这里的来源： http://entityframework.codeplex.com/SourceControl/latest#src/EntityFramework/Core/Common/EntitySql/AST/BuiltInKind.cs

您必须将AST添加到AST并生成它. Here’s a basic tutorial on DBProviders.