Trigraphs are allowed in SQL statements. In the current versions of DP4 trigraphs are automatically enabled for SQLDDE, but not otherwise. For SQLEXE this feature can be enabled by running SQLEXE with the following command tail:
SQLEXE -TRIGRAPH
The table shows the special sequences of characters interpreted as escape sequences.
| Trigraph | Interpreted as | Trigraph | Interpreted as |
|---|---|---|---|
|
??a |
@ |
??n |
^ |
|
??b |
( |
??o |
, |
|
??c |
: |
??p |
+ |
|
??d |
" |
??q |
' |
|
??e |
= |
??r |
* |
|
??g |
> |
??s |
; |
|
??h |
/ |
??t |
. |
|
??k |
) |
??u |
_ |
|
??l |
< |
??x |
! |
|
??m |
- |
??? |
? |
The expansion of trigraphs is done even within quotes. A single question mark is interpreted as that, but two in succession are treated as the start of a trigraph. For example, to get two question marks into the SQL statement, you must enter six successive question marks.
The intention of this feature is to allow characters to be inserted into the SQL statement with which the requester program is incapable of dealing.
Contact Itim Technology Solutions Customer care if you require support for SQL Trigraphs in an ODBC connection to a DP4 database. This would be a simple enhancement and can be made if necessary.