Ensure that BEFORE STATEMENT triggers fire the right number of times.

Commit 0f79440fb introduced mechanism to keep AFTER STATEMENT triggers
from firing more than once per statement, which was formerly possible
if more than one FK enforcement action had to be applied to a given
table.  Add a similar mechanism for BEFORE STATEMENT triggers, so that
we don't have the unexpected situation of firing BEFORE STATEMENT
triggers more often than AFTER STATEMENT.

As with the previous patch, back-patch to v10.

Discussion: https://postgr.es/m/22315.1505584992@sss.pgh.pa.us

2 files changed, 18 insertions, 0 deletions

diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out
index 3ab6be3421c..85d948741ed 100644
--- a/src/test/regress/expected/triggers.out
+++ b/src/test/regress/expected/triggers.out
@@ -2289,6 +2289,9 @@ create table refd_table (a int primary key, b text);
 create table trig_table (a int, b text,
   foreign key (a) references refd_table on update cascade on delete cascade
 );
+create trigger trig_table_before_trig
+  before insert or update or delete on trig_table
+  for each statement execute procedure trigger_func('trig_table');
 create trigger trig_table_insert_trig
   after insert on trig_table referencing new table as new_table
   for each statement execute procedure dump_insert();
@@ -2309,8 +2312,10 @@ insert into trig_table values
   (2, 'two b'),
   (3, 'three a'),
   (3, 'three b');
+NOTICE:  trigger_func(trig_table) called: action = INSERT, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = trig_table_insert_trig, new table = (1,"one a"), (1,"one b"), (2,"two a"), (2,"two b"), (3,"three a"), (3,"three b")
 update refd_table set a = 11 where b = 'one';
+NOTICE:  trigger_func(trig_table) called: action = UPDATE, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = trig_table_update_trig, old table = (1,"one a"), (1,"one b"), new table = (11,"one a"), (11,"one b")
 select * from trig_table;
  a  |    b    
@@ -2324,6 +2329,7 @@ select * from trig_table;
 (6 rows)
 
 delete from refd_table where length(b) = 3;
+NOTICE:  trigger_func(trig_table) called: action = DELETE, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = trig_table_delete_trig, old table = (2,"two a"), (2,"two b"), (11,"one a"), (11,"one b")
 select * from trig_table;
  a |    b    
@@ -2338,6 +2344,9 @@ drop table refd_table, trig_table;
 --
 create table self_ref (a int primary key,
                        b int references self_ref(a) on delete cascade);
+create trigger self_ref_before_trig
+  before delete on self_ref
+  for each statement execute procedure trigger_func('self_ref');
 create trigger self_ref_r_trig
   after delete on self_ref referencing old table as old_table
   for each row execute procedure dump_delete();
@@ -2346,7 +2355,9 @@ create trigger self_ref_s_trig
   for each statement execute procedure dump_delete();
 insert into self_ref values (1, null), (2, 1), (3, 2);
 delete from self_ref where a = 1;
+NOTICE:  trigger_func(self_ref) called: action = DELETE, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = self_ref_r_trig, old table = (1,), (2,1)
+NOTICE:  trigger_func(self_ref) called: action = DELETE, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = self_ref_r_trig, old table = (1,), (2,1)
 NOTICE:  trigger = self_ref_s_trig, old table = (1,), (2,1)
 NOTICE:  trigger = self_ref_r_trig, old table = (3,2)
@@ -2355,6 +2366,7 @@ NOTICE:  trigger = self_ref_s_trig, old table = (3,2)
 drop trigger self_ref_r_trig on self_ref;
 insert into self_ref values (1, null), (2, 1), (3, 2), (4, 3);
 delete from self_ref where a = 1;
+NOTICE:  trigger_func(self_ref) called: action = DELETE, when = BEFORE, level = STATEMENT
 NOTICE:  trigger = self_ref_s_trig, old table = (1,), (2,1), (3,2), (4,3)
 drop table self_ref;
 -- cleanup
diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql
index 30bb7d17b08..2b2236ed7d9 100644
--- a/src/test/regress/sql/triggers.sql
+++ b/src/test/regress/sql/triggers.sql
@@ -1795,6 +1795,9 @@ create table trig_table (a int, b text,
   foreign key (a) references refd_table on update cascade on delete cascade
 );
 
+create trigger trig_table_before_trig
+  before insert or update or delete on trig_table
+  for each statement execute procedure trigger_func('trig_table');
 create trigger trig_table_insert_trig
   after insert on trig_table referencing new table as new_table
   for each statement execute procedure dump_insert();
@@ -1834,6 +1837,9 @@ drop table refd_table, trig_table;
 create table self_ref (a int primary key,
                        b int references self_ref(a) on delete cascade);
 
+create trigger self_ref_before_trig
+  before delete on self_ref
+  for each statement execute procedure trigger_func('self_ref');
 create trigger self_ref_r_trig
   after delete on self_ref referencing old table as old_table
   for each row execute procedure dump_delete();