Question

基本上，我想基于标志用不同的参数执行相同的查询。例如，以下是我的标志为真的情况： -

private static Func<DataClassesDataContext, int, string, IQueryable<DAL.ViewType>> GetFuncComponentsByLibID =
        CompiledQuery.Compile((DataClassesDataContext dCtx, int libID, string searchText) =>
            (from k in dCtx.ViewTypeAttributes where (from r in dCtx.ViewTypeAttributes 
                where r.LibraryID == libID &&
                        r.TypeAttributeValue.Contains(searchText) &&
                        r.TypeAttrStatus == null
                select r.TypeID).Contains(k.TypeID)
                select k));

如果我的标志为false，我想在没有libID参数的情况下执行相同的查询。

private static Func<DataClassesDataContext, int, string, IQueryable<DAL.ViewType>> GetFuncComponentsByLibID =
        CompiledQuery.Compile((DataClassesDataContext dCtx, int libID, string searchText) =>
            (from k in dCtx.ViewTypeAttributes where (from r in dCtx.ViewTypeAttributes 
                where r.TypeAttributeValue.Contains(searchText) &&
                        r.TypeAttrStatus == null
                select r.TypeID).Contains(k.TypeID)
                select k));

Answer 1

最简单的方法是用标志来标记你的标准。

... (!flag || r.LibraryID == libID) ...

如果flag为false，则比较值将为true。

这也是可能的：

private static Func<DataClassesDataContext, int, string, IQueryable<DAL.ViewType>> GetFuncComponentsByLibID =
    CompiledQuery.Compile((DataClassesDataContext dCtx, int libID, string searchText) => {
        if(flag)
            return (from k in dCtx.ViewTypeAttributes where (from r in dCtx.ViewTypeAttributes 
            where r.LibraryID == libID &&
                    r.TypeAttributeValue.Contains(searchText) &&
                    r.TypeAttrStatus == null
            select r.TypeID).Contains(k.TypeID)
            select k);
        else
            return (from k in dCtx.ViewTypeAttributes where (from r in dCtx.ViewTypeAttributes 
            where r.TypeAttributeValue.Contains(searchText) &&
                    r.TypeAttrStatus == null
            select r.TypeID).Contains(k.TypeID)
            select k);
    });

还有一个：

private static Func<DataClassesDataContext, int, string, IQueryable<DAL.ViewType>> GetFuncComponentsByLibID =
    CompiledQuery.Compile((DataClassesDataContext dCtx, int libID, string searchText) => {
        Func<ViewTypeAttributes, bool> whereFunc;
        if(flag)
            whereFunc = new Func<ViewTypeAttributes, bool>(r => r.LibraryID == libID &&
                    r.TypeAttributeValue.Contains(searchText) &&
                    r.TypeAttrStatus == null);
        else
            whereFunc = new Func<ViewTypeAttributes, bool>(r => r.TypeAttributeValue.Contains(searchText) &&
                    r.TypeAttrStatus == null);

        return (from k in dCtx.ViewTypeAttributes where (from r in dCtx.ViewTypeAttributes.Where(whereFunc)
            select r.TypeID).Contains(k.TypeID)
            select k);
    });

如果CompiledQueries中的语句可能？

1 个答案: