Question

I have a query like this:

SELECT a.title,
       a.spec,
       a.name,
       l.User AS CreatedBy,
       DateAdd ( "s", l.time, #03/01/1980# ) AS CreatedAt
FROM 
    (Reports AS a
      INNER JOIN
        AuditLog AS l ON a.id = l.id)
      INNER JOIN
        (SELECT min([time]) AS Mintime,
         id FROM AuditLog GROUP BY id)
        AS t ON (l.time = t.mintime)
      AND (l.id = t.id)
WHERE (((a.ACTIVE)='Y'));

The table Reports has 15000 records and AuditLog has 25800. But this query only returns 7800 results, and I figured there would be more (an audit is generated when a Report is created, so one would assume there’s a matching audit for every Report).

What are some new queries I could make to research what is missing, such as record counts etc? I did try copying this query and using OUTER JOIN, but it gave me “Syntax error in JOIN operation”. Most are active, so removing the WHERE clause is not the cause.

Answer 1

Here’s an example of using Left Join.
This will show all records in Reports, regardless of whether there are matches in the AuditLog table.

Select
  a.title, 
  a.spec, 
  a.name, 
  l.User AS CreatedBy, 
  IIf(IsNull(l.Time), Null, DateAdd ( "s", l.time, #03/01/1980# )) AS CreatedAt
From (
  Reports As a 
    Left Join
  AuditLog AS l 
    On a.id = l.id
  ) Left Join (
    Select
      Min([time]) AS Mintime, 
      id
    From 
      AuditLog 
    Group By
      id
  )  AS t ON (l.id = t.id) AND (l.time = t.mintime)
Where
  a.Active = 'Y';

Here’s an extract from the database documenter feature of my test database:

Table: AuditLog                                             

     Name      Type          Size
     ID        Long Integer  4
     Time      Long Integer  4
     User      Text          255

Table: Reports

     Name      Type          Size
     ID        Long Integer  4
     Title     Text          255
     Spec      Text          255
     Name      Text          255
     Active    Text          255

Query: Test

SQL

     SELECT a.title, a.spec, a.name, l.User AS CreatedBy, DateAdd ( "s", l.time,
     #03/01/1980# ) AS CreatedAt
     FROM (Reports AS a LEFT JOIN AuditLog AS l ON a.id = l.id) LEFT JOIN (SELECT
      Min([time]) AS Mintime, id FROM AuditLog GROUP BY id)  AS t ON (l.id = t.id)
     AND (l.time = t.mintime)
     WHERE a.Active = 'Y'

Columns

     Name      Type          Size
     title     Text          255
     spec      Text          255
     name      Text          255
     CreatedBy Text          255
     CreatedAt Date/Time     8

I notice Access has added some more parentheses in. Also, the documenter missed the where clause for some reason. It’s in the query definition.