WHEN NOT MATCHED BY SOURCE - does not work with a direct table as source

[nLeonardt95]

“WHEN NOT MATCHED BY SOURCE” was introduced with ticket #6681.
This has worked quite well so far.
However, I have now noticed that “WHEN NOT MATCHED BY SOURCE” behaves differently if the source is a stored procedure than if you specify derived-table as the source.

For “WHEN NOT MATCHED BY TARGET”, stored procedure and derived-table behave in the same way.

Here's an example, it may not make much sense, but you can see the difference in a nutshell.

Test-Table

CREATE GENERATOR TEST_ID_GEN;

CREATE TABLE TEST (
    ID        INTEGER NOT NULL,
    TYP       INTEGER,
    CATEGORY  INTEGER
);
ALTER TABLE TEST ADD CONSTRAINT PK_TEST PRIMARY KEY (ID);

SET TERM ^ ;
CREATE OR ALTER TRIGGER TEST_BI0 FOR TEST
ACTIVE BEFORE INSERT POSITION 0
AS
begin
  /* Trigger text */
  if (new.id is null) then
  begin
    new.id = gen_id( test_id_gen, 1);
  end
end^

SET TERM ; ^

Test-Data

INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (1, 1, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (2, 1, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (3, 1, 20);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (4, 1, 20);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (5, 1, 40);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (6, 2, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (7, 2, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (8, 2, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (9, 2, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (10, 2, 10);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (11, 2, 20);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (12, 2, 20);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (13, 2, 30);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (14, 2, 60);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (15, 2, 60);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (16, 2, 60);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (17, 2, 30);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (18, 2, 30);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (19, 2, 30);
INSERT INTO TEST (ID, TYP, CATEGORY) VALUES (20, 2, 30);

Test-Statement

execute block (
    X_SOURCE_TYP type of column TEST.TYP = :SOURCE_TYP,
    X_TARGET_TYP type of column TEST.TYP = :TARGET_TYP)
as
    declare procedure SOURCEDATA
    returns (
        ID       type of column TEST.ID,
        TYP      type of column TEST.TYP,
        CATEGORY type of column TEST.CATEGORY)
    as
    begin
      for select T.ID,
                 T.TYP,
                 T.CATEGORY
      from TEST T
      where T.TYP = :X_SOURCE_TYP
      into :ID,
           :TYP,
           :CATEGORY
      do
      begin
        suspend;
      end
    end

    declare variable WITHSTOREDPROCEDURE boolean;
begin
  --  :WITHSTOREDPROCEDURE = true; -- "when not matched by source" does not work
  :WITHSTOREDPROCEDURE = false; -- works as expected
  if ( :WITHSTOREDPROCEDURE) then
  begin
    -- "when not matched by source" does not work
    merge into TEST T
    using SOURCEDATA S
    on T.TYP = :X_TARGET_TYP and
       T.CATEGORY = S.CATEGORY
    when not matched by target then
        insert ( TYP,
                CATEGORY)
        values ( :X_TARGET_TYP,
                S.CATEGORY);

    merge into TEST T
    using SOURCEDATA S
    on T.CATEGORY = S.CATEGORY
    when not matched by source and T.TYP = :X_TARGET_TYP then delete;
  end
  else
  begin
    -- works as expected
    merge into TEST T
    using ( select T.ID,
                   T.TYP,
                   T.CATEGORY
            from TEST T
            where T.TYP = :X_SOURCE_TYP) S
    on T.TYP = :X_TARGET_TYP and
       T.CATEGORY = S.CATEGORY
    when not matched by target then
        insert ( TYP,
                CATEGORY)
        values ( :X_TARGET_TYP,
                S.CATEGORY);

    merge into TEST T
    using ( select T.ID,
                   T.TYP,
                   T.CATEGORY
            from TEST T
            where T.TYP = :X_SOURCE_TYP) S
    on T.CATEGORY = S.CATEGORY
    when not matched by source and T.TYP = :X_TARGET_TYP then delete;
  end
end

[nLeonardt95]

For your information, I have tested it with Firebird 5.0.1.1469

[asfernandes]

What means "when not matched by source" does not work? Does not work how?
Actually your test do not work at all trying to create duplicate primary key values.

[asfernandes]

I see there is a problem, but not related with stored procedures.
The problem I see is with USING <table>, while USING (select ...) does work.

[nLeonardt95]

What means "when not matched by source" does not work? Does not work how? Actually your test do not work at all trying to create duplicate primary key values.

The problem with USING <stored procedure>is that it does not make a delete, while USING (select ...) execute the delete.

[asfernandes]

Please test fix in next v5 snapshot (or an artifact from https://github.com/FirebirdSQL/firebird/actions/runs/10428291197 when available).

[pavel-zotov]

Have a question about final result in one of cases. Sent report to Adriano, 18.08.2024 11:40. Waiting for reply.