Accessing and Changing Relational Data
Using File Properties for File Content Searches
Microsoft® Indexing Service filters and maintains in excess of 50 file properties. All of these can be specified in text file search queries. From the perspective of writing a SELECT statement, there are 3 types of properties:
- Those that can only be specified in a WHERE clause.
- Those that can be specified in a WHERE clause and, in addition, can be specified in the ORDER BY clause.
- Those that can be specified in a WHERE clause and, in addition, can be specified in a select list.
The table shows a list of the properties.
Property name |
Data type |
Description |
Use in ORDER BY | Use in select list |
|---|---|---|---|---|
| Access | datetime | Most recent date and time that the file was accessed. | Yes | Yes |
| Characterization | nvarchar or ntext | Abstract of the contents of the file. Note that, in this version of Indexing Service this is usually the first paragraph or first section of a document. In a future version, it will be an actual summary. | Yes | |
| Contents | nvarchar or ntext | Main contents of the file. | ||
| Create | datetime | Date and time that the file was created. | Yes | Yes |
| Directory | nvarchar | Physical path to the file, not including the file name. | Yes | Yes |
| DocAuthor | nvarchar | Document author. | Yes | Yes |
| DocComments | nvarchar | Comments about the document. | Yes | Yes |
| DocLastAuthor | nvarchar | Most recent user that edited the document. | Yes | Yes |
| DocLastPrinted | datetime | Date and time that the document was last printed. | Yes | |
| DocPageCount | integer | Number of pages in the document. | Yes | |
| DocPartTitles | array of varchar | Names of document parts: Slide titles in Microsoft PowerPoint® Spreadsheets in Microsoft Excel Documents in Microsoft Word. |
||
| DocSubject | nvarchar | Subject of the document. | Yes | Yes |
| DocTitle | nvarchar | Title of the document. | Yes | Yes |
| DocWordCount | integer | Number of words in the document. | Yes | - |
| FileIndex | decimal(19,0) | Unique identifier of the file. | Yes | Yes |
| FileName | nvarchar | Name of the file. | Yes | Yes |
| HitCount | integer | Number of words matching query. | Yes | Yes |
| Path | nvarchar | Full physical path to the file, including file name. | Yes | Yes |
| Rank | integer | Value from 0 to 1000 indicating how closely this row matches the selection criteria. | Yes | Yes |
| Size | decimal(19,0) | Size of file, in bytes. | Yes | Yes |
Customers and third-party vendors can write filters to add to this set of properties. They can also add properties, for example, by adding their own tags to an HTML document. In addition, to permit the query and retrieval of such user-defined properties, the Transact-SQL extensions to Indexing Service include support for a SET statement that allows the specification of new property names and their associated types.