Character data integrity
The Character Data Representation Architecture (CDRA) system of tags uses coded character set identifiers (CCSIDs) to maintain data integrity when character data is passed from system to system or from user to user. CCSIDs assign a value that uniquely identifies the coded graphic character representation used for character data.
Data integrity is not maintained using CCSID 65535 across countries
The following table shows the meaning of maintaining data integrity. A database file created by a U.S. user contains a dollar sign and is read by a user in the United Kingdom and in Denmark. If the application does not assign CCSID tags that are associated with the data to the file, users see different characters.
| Country | Keyboard type | Code page | CCSID | Code point | Character |
|---|---|---|---|---|---|
| U.S. | USB | 037 | 65535 | X'5B' | $ |
| U.K. | UKB | 285 | 65535 | X'5B' |  |
| Denmark | DMB | 277 | 65535 | X'5B' |  |
Data integrity is maintained by using CCSID tags
If the application assigns a CCSID associated with the data to a file, the application can use IBM i CCSID support to maintain the integrity of the data. When the file is created with CCSID 037, the user in the United Kingdom (job CCSID 285) and the user in Denmark (job CCSID 277) see the same character. Database management takes care of the mapping.
| Country | Keyboard type | Code page | CCSID | Code point | Character |
|---|---|---|---|---|---|
| U.S. | USB | 037 | 00037 | X'5B' | $ |
| U.K. | UKB | 285 | 00285 | X'4A' | $ |
| Denmark | DMB | 277 | 00277 | X'67' | $ |
CCSID support is particularly important when:
- Multiple national language versions, keyboards, and display stations are installed on the IBM i operating system.
- Multiple systems are sharing data between systems with different national language versions.
- The correct keyboard support for a language is not available when you want to encode data in another language.