Mapping Access 2010 Query Expressions In Crystal Reports

Question

Hello,
I am new to Crystal Reports.
When I change the datasource of a Crystal report to an Access 2010 query that has an expression in it, it is not able to map that calculated field. The expression in question is a simple iif statement that yields a yes or no, given the condition that's met. It works fine in Access and is very basic.
But I can't get it to map in Crystal - so I tested it by changing the expression in Access to defect:"x" - even simpler. It still shows up in Crystal as unmapped when I point to the query and hit the Crystal update button.
Can Crystal map expressions in an Access 2010 query, or does it just handle straight table fields that occur in a table or query?
Regards,
Dan

Answer 1

Hello Dan,
When pointing your report from one data source, to another one, the reason it does not initially map the field, it is because they are seen as defined with different data type. One is defined with 255 characters, and the other one is seen as a Memo. In the "Map Fields" window, uncheck  the option "Match type", and you will then be able to map your expression field manually.
Note that the MS Access provider, send the information to Crystal Reports regarding the data type, and the fact it is different, it is because the provider used send different information to Crystal Reports, and if a field is defined with more than 255 characters, it will be seen as a memo field.
There is nothing that can be done in Crystal Reports to change the data type as it is provided by the database provider.
By design, it does not list a memo field as a database field you can group by, because large string generally contains a description, comments, ... and this type of information is generally always different, so there is no reason to group by those field with that data type.
Having said that, it is possible to group by a formula that contains the memo field to give the flexibility to bring back a portion of the characters that the memo field contains. To do so:
1. Create a formula that uses the memo field like:
     {Database.MemoField}   
2. Save and close the formula.
3. Under the menu "Insert", select "Group"
4. In the "Insert Group" window, select the formula created in the previous
steps to group by.
This information is available in the SAP Knowledge Base Article:
     1214731 - Unable to group on a memo field in Crystal Reports
I hope the above information answered your questions.
Patrick