To those who may be wondering, the purpose of this extension is to get
back things like an auto-generated key (or the result of an
in-insert-statement call to a non-pure function) in response to an
insert. All relational DBMSs have some (non-standard AFAIK) hack for
doing this that varies from vendor to vendor / system to system. We
need something like this too, so that a client that's trying to insert
some key-connected objects can get the info needed, efficiently, to do
their work.
On 9/10/16 12:45 AM, Steven Jacobs wrote:
As one of my needs for the bad project, I have extended the language
slightly for the insert statement. Here I am describing the change
that I have made to see if there are any concerns or changes to be
made. At this point it is only the insert that is changed (upsert
didn't exist when I made this change originally). I think it would be
easy to add it to upsert as well if desired.
I Added "return records" and "returning [fieldName]"
"return records" returns to the user all records that were inserted
"returning [fieldName]" returns only the valuse inserted for a single
[fieldName]
examples:
*query:*
create type TweetMessageTypeuuid as closed {
tweetid: uuid,
message-text: string
}
create dataset TweetMessageuuids(TweetMessageTypeuuid)
primary key tweetid autogenerated;
insert into dataset TweetMessageuuids(
[{ "message-text":"hello"}]
) return records;
*top of the plan (only the part after the commit becomes changed):*
distribute result [%0->$$6]
-- DISTRIBUTE_RESULT |PARTITIONED|
exchange
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
project ([$$6])
-- STREAM_PROJECT |PARTITIONED|
commit
-- COMMIT |PARTITIONED|
exchange
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
insert into test:TweetMessageuuids from record: %0->$$6 partitioned by
[%0->$$4]
-- INSERT_DELETE |PARTITIONED|
*result:*
{ "tweetid": uuid("b2c8b24c-2b35-affd-ebcf-6a40f302c780"), "message-text":
"hello" }
query:
create type TweetMessageTypeuuid as closed {
tweetid: uuid,
message-text: string
}
create dataset TweetMessageuuids(TweetMessageTypeuuid)
primary key tweetid autogenerated;
insert into dataset TweetMessageuuids(
[{ "message-text":"hello"}]
) returning tweetid;
top of the plan (only the part after the commit becomes changed):
distribute result [%0->$$4]
-- DISTRIBUTE_RESULT |PARTITIONED|
exchange
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
commit
-- COMMIT |PARTITIONED|
project ([$$4])
-- STREAM_PROJECT |PARTITIONED|
exchange
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
insert into test:TweetMessageuuids from record: %0->$$7 partitioned by
[%0->$$4]
-- INSERT_DELETE |PARTITIONED|
result:
uuid("b2c8b24c-b535-affd-ed4f-0dc961d27b6a")
