You are viewing a plain text version of this content. The canonical link for it is here.
Posted to derby-dev@db.apache.org by "Bryan Pendleton (JIRA)" <ji...@apache.org> on 2016/01/03 01:11:39 UTC
[jira] [Updated] (DERBY-6849) Statement.RETURN_GENERATED_KEYS
returns a 1 row result set even if there are no auto-generated fields
[ https://issues.apache.org/jira/browse/DERBY-6849?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Bryan Pendleton updated DERBY-6849:
-----------------------------------
Description:
If:
1) A JDBC INSERT statement is executed, with Statement.RETURN_GENERATED_KEYS enabled, and
2) A call is then made to Statement.getGeneratedKeys, and
3) The table which was inserted into has *NO* generated columns,
then getGeneratedKeys() returns a ResultSet object with a single row in it.
This behavior seems incorrect; it seems that the correct behavior
would be to return a ResultSet object which has *NO* rows in it, so
that ResultSet.next() returns FALSE the first time it is called.
I have a very simple table:
{noformat}
CREATE TABLE images (
url varchar(1000) NOT NULL,
image blob NOT NULL,
CONSTRAINT images_url PRIMARY KEY (url)
);
{noformat}
No auto-generated fields. However when I do an insert, JDBC tells me there are auto-generated keys (rs.next() does not return false and a LONG value is returned):
{noformat}
try(PreparedStatement statement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
setParameters(parameterValues, statement);
statement.execute();
try(ResultSet rs = statement.getGeneratedKeys()) {
if(rs.next()) {
return rs.getObject(1);
}
return null;
}
}
catch(SQLException e) {
throw new DatabaseException(this, sql + ": " + parameters, e);
}
{noformat}
This sounds like a bug to me. For comparison, PostgreSQL does not have the same behaviour.
was:
I have a very simple table:
{noformat}
CREATE TABLE images (
url varchar(1000) NOT NULL,
image blob NOT NULL,
CONSTRAINT images_url PRIMARY KEY (url)
);
{noformat}
No auto-generated fields. However when I do an insert, JDBC tells me there are auto-generated keys (rs.next() does not return false and a LONG value is returned):
{noformat}
try(PreparedStatement statement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
setParameters(parameterValues, statement);
statement.execute();
try(ResultSet rs = statement.getGeneratedKeys()) {
if(rs.next()) {
return rs.getObject(1);
}
return null;
}
}
catch(SQLException e) {
throw new DatabaseException(this, sql + ": " + parameters, e);
}
{noformat}
This sounds like a bug to me. For comparison, PostgreSQL does not have the same behaviour.
Summary: Statement.RETURN_GENERATED_KEYS returns a 1 row result set even if there are no auto-generated fields (was: Statement.RETURN_GENERATED_KEYS returns "keys" even if there are no auto-generated fields)
John, I attempted to reword your observation about the behavior,
based on our discussion. Please let me know what you think.
> Statement.RETURN_GENERATED_KEYS returns a 1 row result set even if there are no auto-generated fields
> -----------------------------------------------------------------------------------------------------
>
> Key: DERBY-6849
> URL: https://issues.apache.org/jira/browse/DERBY-6849
> Project: Derby
> Issue Type: Bug
> Components: JDBC
> Affects Versions: 10.9.1.0
> Reporter: John Hendrikx
> Attachments: DERBY6849Repro.java
>
>
> If:
> 1) A JDBC INSERT statement is executed, with Statement.RETURN_GENERATED_KEYS enabled, and
> 2) A call is then made to Statement.getGeneratedKeys, and
> 3) The table which was inserted into has *NO* generated columns,
> then getGeneratedKeys() returns a ResultSet object with a single row in it.
> This behavior seems incorrect; it seems that the correct behavior
> would be to return a ResultSet object which has *NO* rows in it, so
> that ResultSet.next() returns FALSE the first time it is called.
>
> I have a very simple table:
> {noformat}
> CREATE TABLE images (
> url varchar(1000) NOT NULL,
> image blob NOT NULL,
>
> CONSTRAINT images_url PRIMARY KEY (url)
> );
> {noformat}
> No auto-generated fields. However when I do an insert, JDBC tells me there are auto-generated keys (rs.next() does not return false and a LONG value is returned):
> {noformat}
> try(PreparedStatement statement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
> setParameters(parameterValues, statement);
> statement.execute();
> try(ResultSet rs = statement.getGeneratedKeys()) {
> if(rs.next()) {
> return rs.getObject(1);
> }
> return null;
> }
> }
> catch(SQLException e) {
> throw new DatabaseException(this, sql + ": " + parameters, e);
> }
> {noformat}
> This sounds like a bug to me. For comparison, PostgreSQL does not have the same behaviour.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)