Add udtf SQL prefix

[SanjulaGanepola]

Changes

This PR adds udtf as a new SQL prefix for generating the skeleton for a user-defined table function as requested in #458

[github-actions]

👋 A new build is available for this PR based on 226e6b2.

• Download here.
• Read more about how to test

[forstie]

I think we should add some of the most important UDTF keywords.

NOT DETERMINISTIC
NO EXTERNAL ACTION
READS SQL DATA
SET OPTION
COMMIT = *NONE ,
DYNUSRPRF = *USER ,
USRPRF = *USER

[SanjulaGanepola]

I think we should add some of the most important UDTF keywords.

Done! I updated the screen cap above

[forstie]

ON Common1, I did
udtf: select * from dogshow.account

Any and all columns returned by the udtf should be referenced by name.
Using SELECT * means that the UDTF will break when a column is added later.

`-- statement:
-- select * from dogshow.account

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
RETURNS TABLE (
CLINAME VARCHAR(100)
)
NOT DETERMINISTIC
NO EXTERNAL ACTION
READS SQL DATA
SET OPTION COMMIT = *NONE,
DYNUSRPRF = *USER,
USRPRF = *USER
BEGIN
RETURN select * from dogshow.account;
END;`

[forstie]

Delimited column names aren't handled by the support.
Example:

-- statement:
-- update: SELECT "cLo" FROM "CaMel"."CoWt"

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
  RETURNS TABLE (
    cLo INTEGER
  )
  NOT DETERMINISTIC
  NO EXTERNAL ACTION
  READS SQL DATA
  SET OPTION COMMIT = *NONE,
             DYNUSRPRF = *USER,
             USRPRF = *USER
  BEGIN
    RETURN SELECT * FROM "CaMel"."CoWt";
  END;

[chrjorgensen]

@SanjulaGanepola See comments by @forstie for required changes.

[SanjulaGanepola]

@forstie @chrjorgensen This PR is ready for review and testing again.

udtf: select * from dogshow.account

-- statement:
-- select * from dogshow.account

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
  RETURNS TABLE (
    CLINAME VARCHAR(100)
  )
  NOT DETERMINISTIC
  NO EXTERNAL ACTION
  READS SQL DATA
  SET OPTION COMMIT = *NONE,
             DYNUSRPRF = *USER,
             USRPRF = *USER
  BEGIN
    RETURN select CLINAME
            from dogshow.account;
  END;

udtf: SELECT "cLo" FROM "CaMel"."CoWt"

-- statement:
-- SELECT "cLo" FROM "CaMel"."CoWt"

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
  RETURNS TABLE (
    cLo INTEGER
  )
  NOT DETERMINISTIC
  NO EXTERNAL ACTION
  READS SQL DATA
  SET OPTION COMMIT = *NONE,
             DYNUSRPRF = *USER,
             USRPRF = *USER
  BEGIN
    RETURN SELECT "cLo" FROM "CaMel"."CoWt";
  END;

[forstie]

CEAC had a good comment in general, that applies here.

We could include DBGVIEW = *SOURCE in the Set Option statement.
Or at least include it commented out?

[forstie]

I think I have the vsix properly updated.
I am seeing...

udtf: select * from dogshow.account;

Create this, which is wrong

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
RETURNS TABLE (
CLINAME VARCHAR(100)
)
NOT DETERMINISTIC
NO EXTERNAL ACTION
READS SQL DATA
SET OPTION COMMIT = *NONE,
DYNUSRPRF = *USER,
USRPRF = *USER
BEGIN
RETURN CLINAME
select * from dogshow.account;
END;

[SanjulaGanepola]

@forstie Can you try installing the version here: https://github.com/codefori/vscode-db2i/actions/runs/19973304026/artifacts/4780743820

[forstie]

I did the install over again, cmd-Q to kill vs, restarted and still see this

[SanjulaGanepola]

@forstie I gave this a try again and it works fine on my end. I also had Devansh try this out and it also works for him (he has a Mac). Can you give this a try once more?

@chrjorgensen Would you be able to give this a try?

[forstie]

When I started to use a different IBM i, this feature started to work for me. :)

udtf: SELECT account_id, cast(null as clob(1k)) as col2 FROM BRANCH_OFFICE_099.TRANSACTIONS as a

Produces

Please have a look

[forstie]

I added a comment with a query that doesn't generate cleanly using the new udtf: keyword.
Please take a look at it.

[SanjulaGanepola]

@forstie Thanks for the review. I ended up fixing two issues you found:

1. The issue you ran into here where random column names were appearing incorrectly should be addressed now
2. The issue you ran into here should also be fixed. I added support for more built-in data types: https://github.com/codefori/vscode-db2i/pull/459/files#diff-b623628cf0577b6d13e04dd300c1256f612379dd6351e336eea9650c135f8009R107-R166. Let me know if anything is missing from this set. I got this based on https://www.ibm.com/docs/en/i/7.6.0?topic=statements-create-table

[forstie]

The improvements work very well, thank you.
Along the way, I noticed that if the query has unnamed columns, the resulting CREATE FUNCTION is syntactically invalid.
Now, of course the user of this tool should decide on a good name, so I think I'm AOK with the current behavior.
I just wanted to make sure that you knew.

udtf: select lower('HI') from sysibm.sysdummy1;

-- User-defined table function
CREATE OR REPLACE FUNCTION MyFunction()
RETURNS TABLE (
00001 VARCHAR(2)
)
NOT DETERMINISTIC
NO EXTERNAL ACTION
READS SQL DATA
SET OPTION COMMIT = *NONE,
DBGVIEW = *SOURCE,
DYNUSRPRF = *USER,
USRPRF = *USER
BEGIN
RETURN select lower('HI') from sysibm.sysdummy1;
END;

[forstie]

Very nice strides forward. Well done!

Comments addressed. Lets merge!