ms-access：数据库引擎找不到输入表或查询

Question

here's the query:

SELECT *
FROM (SELECT [Occurrence Number], [Occurrence Date], [1 0 Preanalytical (Before Testing)], [Cup Type], NULL as [2 0 Analytical (Testing Phase)], [2 0 Area], NULL as [3 0 Postanalytical ( After Testing)],NULL as  [4 0 Other], [Practice Code], [Specimen ID #] FROM [Lab Occurrence Form] 
WHERE NOT ([1 0 Preanalytical (Before Testing)] IS NULL)
  UNION
  SELECT [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],[2 0 Analytical (Testing Phase)],  [2 0 Area], NULL,NULL, [Practice Code], [Specimen ID #] FROM  [Lab Occurrence Form]  WHERE NOT ([2 0 Analytical (Testing Phase)] IS NULL)
  UNION
  SELECT  [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],NULL,  [2 0 Area], [3 0 Postanalytical ( After Testing)],NULL, [Practice Code], [Specimen ID #] FROM  [Lab Occurrence Form]  WHERE NOT ([3 0 Postanalytical ( After Testing)] IS NULL)
 UNION
  SELECT  [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],NULL, [2 0 Area], NULL,  [4 0 Other] FROM  [Lab Occurrence Form], [Practice Code], [Specimen ID #]  WHERE NOT ([4 0 Other] IS NULL)
)  AS mySubQuery
ORDER BY mySubQuery.[Occurrence Number];

for some reason it doesnt like [Practice Code]. it's definitely a column in the table so i dont understand the problem.

the error is

the microsoft office access database engine cannot find the input table or query 'Practice Code'........

Answer 1

Well, the error says it all. It is not a table. In your question, you state that it is a column in a table. You have [Lab Occurrence Form], [Practice Code], [Specimen ID #] right after a from, so it assumes all those listed there are tables.

Answer 2

The last SQL SELECT in the UNION has a messed up FROM clause:

  SELECT [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],NULL, [2 0 Area], NULL,  [4 0 Other] 
  FROM  [Lab Occurrence Form], [Practice Code], [Specimen ID #]  
  WHERE NOT ([4 0 Other] IS NULL) 

You seem to have put two fields in the FROM clause, [Practice Code] and [Specimen ID #].