Question

For a table structured as such:

"Object Attribute" Table - Links objects with all of their attributes and values;
Object ID       Attribute ID    Attribute String Value  ...
1337            123             Example Object Title
1337            124             Example Object Type
1337            125             Example Object Description
1337            126             Example Object Author
0001            123             (null)
0001            124             SomeType
0001            125             This is an example record
0001            126             Jiman
0002            123             Bar
0002            124             BarType
0002            125             This is another
0002            126             Jiman

EDIT: Attribute ID’s have the following mapping:

Attribute ID    Attribute Name
123             Title
124             Type
125             Description
126             Author

How would I compose an Oracle query that returns a transposed set of data, where the Title field is NULL?

Example output:

ID      Title       Type        Description             Author
0001    (null)      FooType     This is an example...   Jiman

Can PIVOT be used to transpose non-aggregate values (i.e., those string attributes)?

Answer 1

The simplest approach, assuming you want the mapping from attribute ID to attribute name to be hard-coded in the query and that you know the number of elements you want in the result at compile time, would be something like

SELECT *
  FROM (
    SELECT object_id,
           MAX( CASE WHEN attribute_id = 123 THEN attribute_string_value ELSE NULL END) title,
           MAX( CASE WHEN attribute_id = 124 THEN attribute_string_value ELSE NULL END) type,
           MAX( CASE WHEN attribute_id = 125 THEN attribute_string_value ELSE NULL END) description,
           MAX( CASE WHEN attribute_id = 126 THEN attribute_string_value ELSE NULL END) author
      FROM your_table_name
     GROUP BY object_id )
  WHERE title IS NULL

If you only need to support 11g, you could use the PIVOT operator as well.