Syntax
| Visual Basic (Declaration) | |
|---|---|
Public Event OnDefineIndex As TDefineIndexEvent | |
| Visual Basic (Usage) |  Copy Code |
|---|---|
Dim instance As TOLAPCube Dim handler As TDefineIndexEvent AddHandler instance.OnDefineIndex, handler | |
| C# | |
|---|---|
public event TDefineIndexEvent OnDefineIndex | |
| Managed Extensions for C++ | |
|---|---|
public: __event TDefineIndexEvent* OnDefineIndex | |
| C++/CLI | |
|---|---|
public: event TDefineIndexEvent^ OnDefineIndex | |
Example
| C# | Copy Code |
|---|---|
private void OLAPCube_OnDefineIndex(object Sender, TDefineIndexArgs e) { // Here we can index the tables we're gonna search for the records if (e.ThisTable("Categories")) // The index named "Category" will index the table by the "CategoryName" field e.Indexes.AddKeyColumns("Category", "CategoryName"); } | |
Remarks
The event occurs when a table is about to start reading table's records from the database. This is the time and place to define indexes available for a table. If there is a primary index for a table then it is already defined by the time the event occurs.
The event handler takes a single parameter of the TDefineIndexArgs class, which among other properties has the Indexes collection. This property is a collection of indexes available for the table. If there is a primary index then it already exists in the collection. The main purpose of the event handler is to create additional indexes (a table index is represented by TDataIndex class) and insert them into the Indexes collection.
You can do that by using the methods of TDataIndexCollection class, namely AddKeyColumns, which is the best way to create new indexes and define key columns for them. See the description of the method for details.
Requirements
Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family