Field_Index - DataDictionary
Returns the main index for a table column
Type: Property
Access: Read-Only
Data Type: Integer
Parameters: None
Parameters
| Parameter | Type | Description |
|---|---|---|
| iField | Integer | Number of the column in the table |
Syntax
Property Integer Field_Index
| Access Type | Syntax |
|---|---|
| Read Access: | Get Field_Index to IntegerVariable |
Description
Field_Index retrieves the main index for a column. If the DDO's Ordering property is explicitly set (i.e., it is non-zero) that value will be returned. If it is not, the main index assigned that table and column will be returned. If no index is assigned, -1 is returned.
Use
Get Field_Index of hDD iField to iIndex
Get Field_Index of hDD Field FileName.FieldName to iIndex
Function Field_Index integer iField returns Integer
: // augment as needed
End_Function
This property is usually called by File_Field_Index, which operates by finding the DDO that "owns" the passed table and sending the message Field_Index to that object. Therefore the message is actually resolved within Field_Index in the DDO owner object. For this reason, you should never augment File_Field_Index; augment Field_Index instead.
When accessing this property, you can use either File_Field_Index or Field_Index. Using File_Field_Index is easier because you do not have to worry whether the message is sent to the correct DDO - it will find the owner DDO and send the message Field_Index.
When augmenting this method, always augment Field_Index in the owner DD to be sure that it will get called.
File and File_Field Interfaces
Many of the DataDictionary methods contain a two variants of the same message: Field_Message and File_Field_Message. For a complete description of these messages please refer to The Field and File_Field DD Interfaces.
The Field_ version of a message must use the keyword FIELD to identify the Table.Column name. The File_Field_ version must use the keyword FILE_FIELD to identify the Table.Column name. These should never be mixed!
// When using Field_ message use the FIELD keyword
Get Field_Index Field Customer.Name to sIndex
// When using the File_Field_ message use the FILE_FIELD keyword
Get File_Field_Index of oCustomer_DD File_Field Customer.Name to sIndex
| Col 1 | Col 2 |
|---|---|
| Note: | The messages File_Field_Index and Field_Index were created to replace the now obsolete message Field_Main_Index. |
See Also