SourceColumn (clsColumn)
.gif "Hinweis") Hinweis |
|---|
Diese Funktion wird in der nächsten Version von Microsoft SQL Server entfernt. Verwenden Sie diese Funktion beim Entwickeln neuer Anwendungen nicht, und planen Sie so bald wie möglich das Ändern von Anwendungen, in denen es zurzeit verwendet wird. |
The SourceColumn property of an object of ClassType clsColumn identifies the name of its source column in a relational table. This property applies only to columns belonging to mining model objects of SubClassType sbclsRegular.
Data Type
String
Access
Read/write for columns with a SubClassType of sbclsRegular, read-only for all others.
Hinweise
For columns with a SubClassType of sbclsNested that belong to a mining model object of SubClassType of sbclsRegular, this property returns an empty string.
To understand the function of this property, consider the relationships of columns in a model to an SQL query. If you use a SELECT query to define the structure of a table when you create a mining model, the contents of this property for each column in the model correspond to a column designation within the SELECT query. For example, consider the following query:
SELECT "Key" AS "CustId", "Age" AS "Age" FROM "People"
If a mining model were to be created using this SELECT statement, the SourceColumn properties for each column would be "Key" and "Age" respectively.
Examples
Creating a Data Mining Model
The following example creates a data mining model based upon the People table of a relational database. This table is specified by the FromClause property. Because the model is based upon a single table, no joins are needed. It then creates and adds two columns to the model's Columns collection. Each column is related to a field in the original relational table (that is to say, the People table) by setting the SourceColumn property of each column to the appropriate value.
dsoDmm.Description = "Analyzes the purchasing behavior of customers"
dsoDmm.MiningAlgorithm = "Microsoft_Decision_Trees"
dsoDmm.FromClause = "People"
dsoDmm.JoinClause = "" ' None is needed because there is only a single table.
dsoDmm.Filter = ""
dsoDmm.TrainingQuery = "" 'Let DSO figure out the training query.
Set dsoColumn = dsoDmm.Columns.AddNew("CustId")
dsoColumn.SourceColumn = "People.Key"
dsoColumn.DataType = adInteger
dsoColumn.IsKey = True
Set dsoColumn = dsoDmm.Columns.AddNew("Age")
dsoColumn.SourceColumn = "People.Age"
dsoColumn.DataType = adDouble
dsoColumn.ContentType = "CONTINUOUS"