John English created DERBY-6779:
-----------------------------------
Summary: Provide subclass of SQLException for duplicate key
insertions
Key: DERBY-6779
URL: https://issues.apache.org/jira/browse/DERBY-6779
Project: Derby
Issue Type: Improvement
Components: SQL
Reporter: John English
Priority: Minor
A commonly-occurring situation is to take some special action when an insert
fails due to a duplicate key; for example, to update the existing row or to
retry the insert with a new key (e.g. mutate "Name" into "Name(1)", "Name(2)"
etc. until a unique key is found). At present this requires code similar to:
{noformat}
try {
//... insert new row
}
catch (SQLException e) {
if (e.getSQLState().equals(DUPLICATE_KEY)) {
// ... take recovery action
}
else {
throw e;
}
}
{noformat}
It would be more convenient if a subclass of SQLException were used to report
this precise error. The SQLIntegrityConstraintViolationException that is
currently thrown will also be thrown in other case where a constraint is
violated. A new exception subclass for this specific situation would not affect
any existing code, and would allow the code above to be simplified to this:
{noformat}
try {
//... insert new row
}
catch DuplicateKeyException e) {
// ... take recovery action
}
{noformat}
This would allow a more elegant, more O-O solution to what is, in my
experience, a common use case without having to discriminate based on the value
of getSQLState().
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
