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- Working fields may be defined as TYPE(*STRING).
- Fields of type String or Char and length of 256 or less may be used almost anywhere that fields of type Alpha may be used.
- A string of zero length has a space added to it before inserting or updating the database via SQL. This is in order to obtain consistent behaviour between our databases. Without a space, Oracle interprets the data as being SQL Null, which is not strictly true and is not how the other databases behave.
So, be aware that your application cannot make a distinction between an empty String and a String with 1 blank. Also, concatenations of a zero length String before inserting to the database and after reading may differ by the extra space. Behaviour can be made consistent by truncating trailing spaces before using Strings in an expression. Note that when comparing an empty String in RDML to a String with 1 space read from the database they will compare equal because trailing spaces are not significant in comparisons - they are only significant in expressions, like concatenation.
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- Refer to Platform Considerations in 1.1.1 Field Type Considerations.