Performs a bulk copy of a source record to
a target record by copying each source field to the target field
of the same name. You can specify a list of fields to exclude from
the bulk copy, or a list of fields to include in the bulk copy.
You can also specify WHEN...THEN phrases. For each such phrase,
BUFFER-COPY executes the THEN portion if the corresponding WHEN
portion evaluates to TRUE.
Syntax
BUFFER-COPY source [ { EXCEPT | USING } field ... ]
TO target [ ASSIGN assign-expression ... ] [ NO-LOBS ] [ NO-ERROR ]
|
-
source
- The source database table, buffer, temp-table, or work table.
- EXCEPT field ...
- A list of space-separated source fields to exclude from the
bulk copy.
- USING field ...
- A list of space-separated source fields to include in the bulk
copy. The USING option is simply a positive version of the EXCEPT option.
- TO target
- The source database table, buffer, temp-table, or work table.
- ASSIGN assign-expression
- A space-separated list of any valid ABL ASSIGN statements (without the
EXCEPT option, which BUFFER-COPY already provides). BUFFER-COPY
performs each assign-expression and automatically
excludes the field on the left side ("destination") of each assign-expression from
the bulk copy-except for field extents (subscripted fields). If
a field extent appears on the left side of an assign-expression,
BUFFER-COPY does not automatically exclude that extent (such as
customer.mnth-sales[1]) or the field as a whole (such as customer.mnth-sales)
from the bulk copy.
- NO-LOBS
- Directs the AVM to ignore large object data when copying records that contain BLOB or
CLOB fields.
Caution:
Using this option can create the potential for errors
in your data and lead to inappropriate results. Therefore, before using this option,
you must understand the nature of your data and be sure that logic using this option
will not result in inconsistent or out-of-date data in the database.
- NO-ERROR
- Suppresses ABL errors or error messages that would otherwise occur and diverts them to
the ERROR-STATUS system handle. If an error occurs, the
action of the statement is not done and execution continues with the next statement. If
the statement fails, any persistent side-effects of the statement are backed out. If the
statement includes an expression that contains other executable elements, like methods,
the work performed by these elements may or may not be done, depending on the order the
AVM resolves the expression elements and the occurrence of the error.
To check for
errors after a statement that uses the NO-ERROR option:
- Check the ERROR-STATUS:ERROR attribute to see if the AVM raised the ERROR
condition.
- Check if the ERROR-STATUS:NUM-MESSAGES attribute is greater than zero to see if
the AVM generated error messages. ABL handle methods used in a block without
a CATCH end block treat errors as warnings and do not raise ERROR, do not set the
ERROR-STATUS:ERROR attribute, but do add messages to the ERROR-STATUS system handle.
Therefore, this test is the better test for code using handle methods without CATCH
end blocks. ABL handle methods used in a block with a CATCH end block raise
ERROR and add messages to the error object generated by the AVM. In this case, the
AVM does not update the ERROR-STATUS system handle.
- Use ERROR-STATUS:GET-MESSAGE( message-num ) to retrieve a
particular message, where message-num is 1 for the first
message.
If the statement does not include the NO-ERROR option, you can use a CATCH end
block to handle errors raised by the statement.
Some other important usage notes
on the NO-ERROR option:
- NO-ERROR does not suppress errors that raise the STOP or QUIT condition.
- A CATCH statement, which introduces a CATCH end block, is analogous to a NO-ERROR
option in that it also suppresses errors, but it does so for an entire block of
code. It is different in that the error messages are contained in a class-based
error object (generated by the AVM or explicitly thrown), as opposed to the
ERROR-STATUS system handle. Also, if errors raised in the block are not handled by a
compatible CATCH block, ON ERROR phrase, or UNDO statement, then the error is not
suppressed, but handled with the default error processing for that block type.
- When a statement contains the NO-ERROR option and resides in a block with a CATCH
end block, the NO-ERROR option takes precedence over the CATCH block. That is, an
error raised on the statement with the NO-ERROR option will not be handled by a
compatible CATCH end block. The error is redirected to the ERROR-STATUS system
handle as normal.
- If an error object is thrown to a statement that includes the NO-ERROR option,
then the information and messages in the error object will be used to set the
ERROR-STATUS system handle. This interoperability feature is important for those
integrating code that uses the traditional NO-ERROR technique with the newer,
structured error handling that features error objects and CATCH end blocks.
