[
https://issues.apache.org/jira/browse/DERBY-6779?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
John English updated DERBY-6779:
--------------------------------
Description:
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) { // or some suitable name
// ... 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().
was:
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().
> 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) { // or some suitable name
> // ... 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().
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