亚音速单个 WHERE 子句

Question

是否可以在 SubSonic 查询上应用 WHERE 子句？

例如，我根据 id 获得单曲...

db.Single<Storage>(id);

但是如何根据简单的 WHERE 子句获得单曲？

db.Single<Storage>(WHERE columnname == "value");

Answer 1

这是可能的：

// Will return a Storage instance with property IsNew = true, if record does not exist
// since an object created with new never can be null
var storage1 = new Storage(1); // id = 1
var storage1 = new Storage(Storag.Columns.ColumnName, "value");

// Will return 0 if record not found (subsonic3 only)
var storage3 = (from s in Storage
               where s.ColumnName == "value"
               select s).SingleOrDefault();

// Will throw an exception if record not found  (subsonic3 only)
var storage3 = (from s in Storage
               where s.ColumnName == "value"
               select s).Single();   

由于 db 是一个分部类，您可以扩展它。只需在同一命名空间（但解决方案中的另一个文件夹）中创建一个新文件。我认为这适用于亚音速 2，但与亚音速 3 类似。

public static partial class DB
{
    public static T Single<T>(String columName, Object columnValue) where T: RecordBase<T>, new()
    {
        return Select().From<T>()
                       .Where(columnName).IsEqualTo(columnValue)
                       .ExecuteSingle<T>();
    }
}

Answer 2

感谢以上内容，这是一个帮助，最终我将其简化为以下......

        db.Single<Storage>(s => s.ColumnName == "value");