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Add Parser::DBI::PostgreSQL support for proc / trigger #195

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983be4a
Add Parser::DBI::PostgreSQL support for proc / trigger
nrdvana Nov 3, 2025
152466b
Code formatting and comment tweaks to previous
nrdvana Dec 8, 2025
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128 changes: 128 additions & 0 deletions lib/SQL/Translator/Parser/DBI/PostgreSQL.pm
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Original file line number Diff line number Diff line change
Expand Up @@ -134,6 +134,63 @@ ORDER BY 1;
/
) or die "Can't prepare: $@";

# Select all user-defined triggers from the Postgres 'public' namespace.
my $trigger_select = $dbh->prepare(<<SQL) or die "Can't prepare trigger query: $@";
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@KES777 KES777 Dec 5, 2025

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I would like to see the description what is the result of these two blocks of code: 'trigger_select' and 'procedure_select'. Eg. this block of code selects triggers and procedures from XXX which we can access later programmatically using YYY

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@nrdvana nrdvana Dec 8, 2025

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Not entirely sure what I can say there... the code itself just prepares the query and follows the style of the code above it. I could comment more on what each field means, but the fields are generally matching the names used on the Trigger and Procedure objects.

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@KES777 KES777 Dec 8, 2025

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Just general comment what this block does and how we can use/access those results.

SELECT
t.tgname AS trigger_name,
c.relname AS table_name,
p.proname AS function_name,
pg_get_triggerdef(t.oid) AS trigger_definition,
CASE t.tgtype & 66
WHEN 2 THEN 'before'
WHEN 64 THEN 'instead of'
ELSE 'after'
END AS timing,
(CASE WHEN (t.tgtype & 4) = 0 THEN '' ELSE 'insert,' END)
|| (CASE WHEN (t.tgtype & 8) = 0 THEN '' ELSE 'delete,' END)
|| (CASE WHEN (t.tgtype & 16) = 0 THEN '' ELSE 'update,' END)
|| (CASE WHEN (t.tgtype & 32) = 0 THEN '' ELSE 'truncate,' END)
AS events,
CASE t.tgtype & 1
WHEN 1 THEN 'row'
ELSE 'statement'
END AS scope,
t.tgattr AS update_columns,
pg_get_expr(t.tgqual, t.tgrelid) AS condition
FROM pg_trigger t
JOIN pg_class c ON t.tgrelid = c.oid
JOIN pg_proc p ON t.tgfoid = p.oid
JOIN pg_namespace n ON c.relnamespace = n.oid
WHERE NOT t.tgisinternal
AND n.nspname = 'public'
ORDER BY c.relname, t.tgname;
SQL

# Select all user-defined procedures from the Postgres 'public' namespace.
my $procedure_select = $dbh->prepare(<<SQL) or die "Can't prepare procedure query: $@";
SELECT
p.proname AS procedure_name,
pg_get_functiondef(p.oid) AS procedure_definition,
pg_catalog.pg_get_function_arguments(p.oid) AS parameters,
pg_catalog.pg_get_function_result(p.oid) AS return_type,
r.rolname AS owner,
d.description AS comments,
CASE p.prokind
WHEN 'f' THEN 'function'
WHEN 'p' THEN 'procedure'
WHEN 'a' THEN 'aggregate'
WHEN 'w' THEN 'window'
ELSE 'unknown'
END AS procedure_type
FROM pg_proc p
JOIN pg_namespace n ON p.pronamespace = n.oid
LEFT JOIN pg_roles r ON p.proowner = r.oid
LEFT JOIN pg_description d ON p.oid = d.objoid AND d.objsubid = 0
WHERE n.nspname = 'public'
AND p.prokind IN ('f', 'p') -- functions and procedures only
ORDER BY p.proname;
SQL

my %enum_types;
if ($deconstruct_enum_types) {
my $enum_select = $dbh->prepare('SELECT enumtypid, enumlabel FROM pg_enum ORDER BY oid, enumsortorder')
Expand Down Expand Up @@ -258,6 +315,77 @@ ORDER BY 1;
}
}

# Process triggers
$trigger_select->execute() or die "Can't execute trigger query: $@";
while (my $trigger_hash = $trigger_select->fetchrow_hashref) {
my $trigger_name = $trigger_hash->{trigger_name};
my $table_name = $trigger_hash->{table_name};
my $timing = $trigger_hash->{timing};
my $events = $trigger_hash->{events};
my $scope = $trigger_hash->{scope};
my $trigger_def = $trigger_hash->{trigger_definition};

# Get the table object
my $table = $schema->get_table($table_name);
next unless $table;

# Parse events into an array
my @database_events = split /,/, $events;

# Handle update column specifications
my @fields = ();
if ($events =~ /update/ && $trigger_hash->{update_columns}) {
# Parse update column list if present
my $update_cols = $trigger_hash->{update_columns};
if ($update_cols && $update_cols ne '') {
@fields = split /\s+/, $update_cols;
}
}

# Extract just the EXECUTE FUNCTION/PROCEDURE part from the trigger definition
my $action = '';
if ($trigger_def =~ /\bEXECUTE\s+(FUNCTION|PROCEDURE)\s+(.+)$/i) {
$action = "EXECUTE $1 $2";
}
# Fallback: capture everything from 'EXECUTE' onward
elsif ($trigger_def =~ /\b(EXECUTE\b.*)$/i) {
$action = $1;
}
else {
die "Could not parse trigger action from '$trigger_def'";
}

# Add trigger to schema
my $trigger = $schema->add_trigger(
name => $trigger_name,
perform_action_when => $timing,
database_events => \@database_events,
on_table => $table_name,
action => $action,
scope => $scope,
(@fields ? (fields => \@fields) : ()),
) || die $schema->error;
}

# Process stored procedures/functions
$procedure_select->execute() or die "Can't execute procedure query: $@";
while (my $proc_hash = $procedure_select->fetchrow_hashref) {
my $proc_name = $proc_hash->{procedure_name};
my $proc_sql = $proc_hash->{procedure_definition};
my $parameters = $proc_hash->{parameters} || '';
my $owner = $proc_hash->{owner};
my $comments = $proc_hash->{comments};

# Add procedure to schema
my $procedure = $schema->add_procedure(
name => $proc_name,
sql => $proc_sql,
parameters => $parameters,
($owner ? (owner => $owner) : ()),
($comments ? (comments => $comments) : ()),
) || die $schema->error;
}

return 1;
}

Expand Down
34 changes: 34 additions & 0 deletions t/66-postgres-dbi-parser.t
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Expand Up @@ -69,6 +69,23 @@ my $sql = q[
-- When the table t_test1 is created, f_text2 get id 5 but
-- after this drop, there is only 4 columns.
alter table sqlt_test1 drop column f_to_drop;

CREATE FUNCTION test_change_notify()
RETURNS TRIGGER AS $$
BEGIN
IF old.f_varchar IS DISTINCT FROM new.f_varchar
THEN
PERFORM pg_notify('test_activity', new.f_serial::text);
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
COMMENT ON function test_change_notify IS 'Testing Comment';

CREATE TRIGGER sqlt_test1_change_notify
BEFORE UPDATE ON sqlt_test1
FOR EACH ROW EXECUTE FUNCTION test_change_notify();

];

$| = 1;
Expand Down Expand Up @@ -207,6 +224,23 @@ is(scalar @t2_constraints, 1, "One constraint on table");
my $t2_c1 = shift @t2_constraints;
is($t2_c1->type, FOREIGN_KEY, "Constraint is a FK");

my @procs = $schema->get_procedures;
is(scalar @procs, 1, 'one user-defined procedure');
is($procs[0]->name, 'test_change_notify', 'proc[0]->name');
like($procs[0]->sql, # Exact SQL syntax varies per server version
qr/create or replace function.*?returns trigger.*IF old.f_varchar IS DISTINCT FROM new.f_varchar/si,
'proc[0]->sql');
is($procs[0]->comments, 'Testing Comment', 'proc[0]->comments');

my @triggers = $schema->get_triggers;
is(scalar @triggers, 1, 'one trigger' );
is($triggers[0]->name, 'sqlt_test1_change_notify', 'trigger[0]->name');
is($triggers[0]->perform_action_when, 'before', 'trigger[0]->perform_action_when');
is_deeply([ $triggers[0]->database_events ], ['update'], 'trigger[0]->database_events');
is($triggers[0]->on_table, 'sqlt_test1', 'trigger[0]->on_table');
is($triggers[0]->scope, 'row', 'trigger[0]->scope');
like($triggers[0]->action, qr/test_change_notify/i, 'trigger[0]->action');

$dbh->rollback;
$dbh->disconnect;

Expand Down
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