Need

You need to transform each row from a SQL query result into an XML element, typically with a generic <row> identifier, and understand how to apply this in an MS-SQL mapping context to generate multi-row XML data.

Summarized Solution

To convert query results into XML format in MS-SQL, you can use the FOR XML RAW clause. This transforms each row into an XML element. When integrating this into a data mapping, you can apply this function to a target field. To ensure distinct rows are generated for specific data, a WHERE clause can be used within the expression.

 

Detailed Solution

Understanding RAW Mode

RAW mode in SQL Server's FOR XML clause transforms each row in your query's result set into an XML element. By default, this element has the generic identifier <row>. However, you can optionally provide a custom element name.

Instructions to Use RAW Mode in an MS-SQL Field

Let's consider a scenario where you're populating an MS-SQL target table, and one of its fields (e.g., XMLDATA) is designed to store XML output from a source table.

  1. Map the Target Field: In your data mapping , map the XMLDATA field in your target table.

  2. Provide the Expression for XML RAW Function: For the XMLDATA field, you'll provide an expression that includes the FOR XML RAW function.

    • Example Scenario: Imagine your source table is DIM_BEDROOM. If you want to perform the XML RAW function on the same table and get data in multiple rows, you would typically define a WHERE clause based on a distinct identifier from that table, such as DIM_BEDROOM.BDR_ID.

  3. Specify the WHERE Clause for Row-Level XML:

    • Note: If you want the entire content from your source table to be broken down into multiple XML rows (one XML snippet per source row), you need to specify a WHERE clause within your expression or SQL query. The WHERE clause will define the content for each distinct XML row.

    • Example result SQL Snippet after using WHERE clause in mapping expression editor:

    • Why the WHERE Clause is Important:

      The WHERE clause ensures that the FOR XML RAW feature converts data from the source into an XML format, with a specific row defined for each XML output. If you do not use a WHERE clause that limits the result set to a single source row per XML generation, then all content from the source (or the query result) will be populated into a single XML field.

      Example: XML RAW without WHERE clause (conceptual output for a single row):