internal void VerfityOutput(ComplexOutputInfo output)
{
if (output != null)
{
Debug.Assert(output.ItemFields.Length == 0 || output.ItemFields.Any(a => a > -1));
foreach (var item in output.Children.OfType <ComplexOutputInfo>())
{
VerfityOutput(item);
}
}
}
/// <summary>
/// 根据分组检索表达式 SingleDefault 初始化查询输出语句及输出对象。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="current">所在数据源。</param>
/// <param name="expression">初始化表达式。</param>
/// <param name="parent">父级输出对象。</param>
protected virtual void InitialRetrievalForSingleDefault(GenerateContext context, ISourceFragment current, DbRetrievalFunctionExpression expression, ComplexOutputInfo parent)
{
var select = current as SelectFragment;
select.Take = 2;
InitialRetrievalForFilter(context, expression, select);
if (parent is ObjectOutputInfo output)
{
output.Option = EObjectOutputOption.ZeroOrOnlyOne;
}
}
/// <summary>
/// 根据分组检索表达式初始化查询输出语句及输出对象。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="current">所在数据源。</param>
/// <param name="expression">初始化表达式。</param>
/// <param name="parent">父级输出对象。</param>
public void InitialRetrieval(GenerateContext context, ISourceFragment current, DbRetrievalFunctionExpression expression, ComplexOutputInfo parent)
{
if (!_InitialRetrievalMethods.TryGetValue(expression.Function, out InitialRetrievalDelegate method))
{
throw new NotSupportedException(string.Format(Res.NotSupportedInitialRetrieval, expression.Function));
}
method(context, current, expression, parent);
}
//分组检索表达式 ElementAt 实现。
private void InitialRetrievalForElementAtImp(GenerateContext context, ISourceFragment current,
DbRetrievalFunctionExpression expression, ComplexOutputInfo parent, EObjectOutputOption option)
{
var value = expression.Arguments[0] as DbConstantExpression;
var select = current as SelectFragment;
select.Take = 1;
select.Skip = (int)value.Value;
if (select.Skip > 0 && select.Sorts.Count == 0)
{
var member = GetFirstMemberForOrder(select);
select.Sorts.Add(new SortFragment(context, member));
}
if (parent is ObjectOutputInfo output)
{
output.Option = option;
}
}
/// <summary>
/// 根据分组检索表达式 ElementAtDefault 初始化查询输出语句及输出对象。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="current">所在数据源。</param>
/// <param name="expression">初始化表达式。</param>
/// <param name="parent">父级输出对象。</param>
protected virtual void InitialRetrievalForElementAtDefault(GenerateContext context, ISourceFragment current, DbRetrievalFunctionExpression expression, ComplexOutputInfo parent)
{
InitialRetrievalForElementAtImp(context, current, expression, parent, EObjectOutputOption.ZeroOrOne);
}