ADO DSC

The ADO data source component (DSC) can be used to read ADO data sources. It consists of the ADO metadata source component (MDSC) and the ADO case data source component (CDSC).

OLAP and certain other OLEDB providers do not represent data in a tabular way so ADO DSC cannot display data from these sources. The recommended approach for handling data sources such as this is to write a customized DSC for the purpose.

ADO MDSC supports the IMetadataLoad interface but not the IMetadataSave interface. It should be initialized with a Location parameter that defines the path to a .adoinfo file.

The .adoinfo file is an XML file that specifies which of the tables in the target datasource should be used to generate metadata. (ADO datasources are typically multi-table entities, whereas many UNICOM Intelligence products assume that a table will exist that is called either VDATA or HDATA.) The format of the .adoinfo file is as follows:

<ADODSC>
<ConnectionString>string</ConnectionString>
<Table>name</Table>
</ADODSC>

▪string is an ADO connection string that is passed verbatim to an ADO Connection object. If the target datasource requires additional security information, you can include this as part of the connection string.

▪name is the name of the table or view to be opened in the datasource. The table or view is opened with the adCommandTable type Recordset.

For more information about writing .adoinfo files, see Example .adoinfo files.

ADO CDSC requires the following information:

▪Connection string. This can be created using the Data Link dialog in DM Query, in the same way as in RDB DSC.

▪Table or view name. Use the MR Project property to specify the name of the table or view from which the case data will be generated. To refer to this table or view in the query, use the name VDATA rather than the original name of the table or view.

ADO CDSC does not support categorical data. If you have columns of data that you want to treat as categorical for the purpose of analysis, you might define either derived variables or axis expressions for the data.

ADO CDSC will not work with all of the OLE DB providers available to ADO. This is because some providers do not expose their data via standard tables, or do not support the adCommandTable method of reading data.

If you are using the Microsoft OLE DB Provider for Oracle, you must specify the Oracle table or view name using uppercase letters, otherwise your SQL queries might not return the correct data.

The DDL includes four sample data management scripts that demonstrate the use of the ADO DSC to read ADO data sources. The scripts are called MSAccessToQuantum.dms, MSAccessToSav.dms, MSExcelToQuantum.dms, and MSExcelToDDF.dms and by default they are installed in:

[INSTALL_FOLDER]\IBM\SPSS\DataCollection\7\DDL\Scripts\Data Management\DMS

For more information about using the ADO DSC in data management scripts, see Transferring data from Microsoft Office using the ADO DSC.