用linqToEntity(Esql)强制转换

Question

我的代码:

public List<Book> GetBook(string NameField, object Value)
    {
        var queryESQL = @"select VALUE Book from Book
                 where Cast(Book." + NameField + " as string) like '%M%'";
        var query = this.Entities.CreateQuery<Book>(
                  queryESQL);
        return query.ToList();
    }

错误:

无法找到"字符串"类型.确保加载了所需的模式,并正确导入名称空间.近型名称,第2行,第51列.

更新:

新代码:

public List<Book> GetBook(string NameField, object Value)
    {
        var queryESQL = @"select VALUE Book from Book
                 where Cast(Book." + NameField + " as EDM.string) like '%M%'";
        var query = this.Entities.CreateQuery<Book>(
                  queryESQL);
        return query.ToList();
    }

错误:

Type 'EDM.string' could not be found. Make sure that the required schemas are loaded and that the namespaces are imported correctly. Near type name, line 2, column 51.

Answer 1

该CreateQuery<>方法使用CLR类型而不是EDM类型,因此使用System.String而不是EDM.String在查询中.