Create an index for a TClientDataSet at runtime

最新推荐文章于 2025-08-14 14:41:48 发布

转载最新推荐文章于 2025-08-14 14:41:48 发布 · 62 阅读

文章标签：

#runtime

博客展示了创建内存表及索引选择的示例。最初用 IndexName 属性创建索引无法选中，而使用 IndexFieldNames 属性选择索引则可行。还给出了创建内存表的代码，包括定义字段、索引，创建数据集并打开等操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

I had originally created the index with the property IndexName
and finally found out that this did not select my index.
Selecting the index by the property IndexFieldNames worked fine,
as the following source shows.

This is also an example how to create a memory table..

  with CDS1 Do
  begin
    Close;
    // Define the fields
    FieldDefs.Clear;
    FieldDefs.Add ('Project', ftInteger, 0, True);
    FieldDefs.Add ('Module',  ftString, 60, False);
    FieldDefs.Add ('FuncName',ftString, 60, False);
    FieldDefs.Add ('FuncDate',ftDate,    0, False);
    FieldDefs.Add ('FuncCRC', ftString,  2, False);
    FieldDefs.Add ('Programmer', ftString, 32, False);
    // Define the index
    IndexDefs.Clear;
    IndexDefs.Add ('IProject', 'Project;Module;FuncName',
                   [ixPrimary, ixUnique]);
    // this seems not to do anything
    IndexName := 'IProject';

    // this does work
    IndexFieldNames := 'Project;Module;FuncName';

    // Create the dataset
    CreateDataSet;
    Open;
  end;