Question

I’ve got three tables

AUTHOR_TABLE ------------- AUTHOR_ID (PK)   AUTHOR_NAME    1                me 2                you   ARTICLE_AUTHOR_TABLE ------------- AUTHOR_ID  ARTICLE_ID   1          100 2          101   EVENT_AUTHOR_TABLE ------------------------------------------ AUTHOR_ID   EVENT_ID   1           200 1           201 

All I want is either

RESULTS ----------------------------------------- AUTHOR_ID AUTHOR_NAME SOURCE_TABLE ID 1         me          article      100 2         you         article      101 1         me          event        200 1         me          event        201   /* where SOURCE_TABLE would be either 'EVENT' or 'ARTICLE' */ 

EDIT I don’t really want this

RESULTS ----------------------------------------- AUTHOR_ID AUTHOR_NAME EVENT_ID ARTICLE_ID 1         me          NULL         100 2         you         NULL         101 1         me          200         NULL 1         me          201         NULL 

Any pointers appreciated.

THanks

Answer 1

SELECT   at.author_id,   at.author_name,   'article' AS source_table,   aat.id FROM   author_table at   JOIN article_author_table aat     ON at.author_id = aat.author_id  UNION ALL  SELECT   at.author_id,   at.author_name,   'event' AS source_table,   eat.id FROM   author_table at   JOIN event_author_table eat     ON at.author_id = eat.author_id