Crosstab query: Getting Null Data for Missing Data from Access DB

问题

I have data in Access Database which contains data for multiple days. But it sometime have missing data for some dates.

In example, I have data for

myDate           Location    Price
11/1/2013        South       10
11/1/2013        West        20
11/1/2013        East        10   
11/2/2013        South       10
11/2/2013        West        20
11/2/2013        East        10   
11/4/2013        South       10   <---- 11/3/2013 Data Missing
11/4/2013        West        30
11/4/2013        East        10

The way I tried to solve it was to find missing date in Access Database, and filled it with Null value using calender table.

myDate           Location    Price
11/1/2013        South       10
11/1/2013        West        20
11/1/2013        East        10   
11/2/2013        South       10
11/2/2013        West        20
11/2/2013        East        10   
11/3/2013                         <---- Null values
11/4/2013        South       10   
11/4/2013        West        30
11/4/2013        East        10

But when I use crosstab query to get get price for each location, 11/3/2013 is skipped because it doesn't have any location related to it.

myDate    South   West   East
11/1/2013 10      20     10
11/2/2013 10      20     10    <---- 11/3/2013 Data skipped
11/4/2013 10      30     10

What I want my solution to be is following:

myDate    South   West   East
11/1/2013 10      20     10
11/2/2013 10      20     10    
11/3/2013                  
11/4/2013 10      30     10

I thought I would be able to use NZ function when I'm calling this data from Access, and whenever I find null value, I can just put #N/A error in Excel spreadsheet so I would be able to catch what data is missing and fill it in later.

How would I accomplish this? Am I doing the right way or is there better way?

Any help or hint would be greatly appreciated.

回答1:

Here's the way I would do it.

Don't include empty dates in the data table. Go back to the way you had it before, where the table only includes valid data.

Create a crosstab query on the table. This will not include the dates that have no data. (From your example:)

myDate    South   West   East
11/1/2013 10      20     10
11/2/2013 10      20     10    <---- 11/3/2013 Data skipped
11/4/2013 10      30     10

Save the crosstab query in your Access database. I'll call it qryXtab. Create a new query left joining your calendar table to qryXtab.

SELECT tblCalendar.cdate, South, West, East
FROM tblCalendar
LEFT JOIN qryXtab
ON tblCalendar.cdate = qryXtab.myDate
ORDER BY tblCalendar.cdate

Use this new query to populate your Excel file. It will include blank rows for dates that have no data.

来源：https://stackoverflow.com/questions/20862358/crosstab-query-getting-null-data-for-missing-data-from-access-db

标签

sql

excel

ms-access

crosstab

missing-data