Crystal Report's Data Dictionary
|Product/Release:||Crystal Reports for LANSA|
|Abstract:||Developing reports even easier with Crystal Reports Data Dictionary|
|Submitted By:||LANSA Technical Support|
The best solution for storing user friendly field and file descriptions, formula fields and file links is in LANSA's Repository. In a similar way to the way that the LANSA Repository puts a user friendly mask on file definitions on the AS/400, so too can the Crystal Data Dictionary be used to put a user friendly mask over the query result files of LANSA Client on a PC or LAN. The administrator may set up a data dictionary, rather then giving users access to the query result files directly. Crystal Data Dictionaries are only used when developing a report, not when running a prepared report.
A few reasons why the Crystal Data Dictionary facility may be used:
- Because of restrictions in the DBase file format, query results produced by LANSA Client always had a limitation of 10 character field names. The Crystal Data Dictionary allows the definition of user friendly long descriptions and default column headings for the query results.
- Some formula fields (virtual fields) may not be available on an AS/400, or they may be seasonal and influenced by date or specific circumstances. These formula fields can now be easily altered in the Crystal Data Dictionary. Having the formula fields on the PC also gives you some easy facilities for "what-if" analysis.
- Date fields from the AS/400 are not recognized as such by Crystal Reports. Defining a conversion formula for numeric fields to date fields in the Crystal Data Dictionary will avoid the need to repeat the same date conversion formula in every report.
- For some specific reports, it may be more efficient to join the files (query results of separate queries) on the PC, rather then running a joined query on the AS/400. For example when the file linking is conditional and only on a selected part of the query result. Defining file links in the Crystal Data Dictionary will shield the users from having to define file links in the reports.
- File locations can be defined in the Crystal Reports data dictionary. When the administrator moves a LANSA query result file to another disk or directory, only the data dictionary (ies) pointing to that file need to be adjusted. The reports that use the dictionary do not need to be adjusted.
- Some limited form of field level security can be achieved with the Crystal Reports Data Dictionary. By omitting certain fields (database fields or formula fields) from a specific data dictionary, the user will not see that field when defining a report. However, the user may still have access to the "raw" Dbase files.
- Some limited form of record level security can be achieved with the Crystal Reports dictionary. It is possible to delete or edit any of the values within a field in the "sample data". This gives some form of record level security based on data contents. However, the user may still have access to the "raw" Dbase files.
To define a Crystal Data Dictionary, select the Crystal Dictionaries item from the Crystal Reports for LANSA group. Define field names, column headers, help text, sample data and file links as required. If a field name "alias" is not defined, it will default to the existing field name. If sample data is not defined, the user will be able to select all records.
To use a data dictionary when creating a report, select the Dictionary option (instead of the Data File option).