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-rw-r--r--doc/src/sgml/func.sgml37
-rw-r--r--src/backend/utils/adt/ruleutils.c11
-rw-r--r--src/test/regress/expected/identity.out6
-rw-r--r--src/test/regress/expected/sequence.out6
-rw-r--r--src/test/regress/sql/identity.sql2
-rw-r--r--src/test/regress/sql/sequence.sql2
6 files changed, 44 insertions, 20 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 641b3b8f4e4..2f036015cc2 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -17034,8 +17034,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<row>
<entry><literal><function>pg_get_serial_sequence(<parameter>table_name</parameter>, <parameter>column_name</parameter>)</function></literal></entry>
<entry><type>text</type></entry>
- <entry>get name of the sequence that a <type>serial</type>, <type>smallserial</type> or <type>bigserial</type> column
- uses</entry>
+ <entry>get name of the sequence that a serial or identity column uses</entry>
</row>
<row>
<entry><literal><function>pg_get_statisticsobjdef(<parameter>statobj_oid</parameter>)</function></literal></entry>
@@ -17223,19 +17222,27 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<para>
<function>pg_get_serial_sequence</function> returns the name of the
sequence associated with a column, or NULL if no sequence is associated
- with the column. The first input parameter is a table name with
- optional schema, and the second parameter is a column name. Because
- the first parameter is potentially a schema and table, it is not treated
- as a double-quoted identifier, meaning it is lower cased by default,
- while the second parameter, being just a column name, is treated as
- double-quoted and has its case preserved. The function returns a value
- suitably formatted for passing to sequence functions (see <xref
- linkend="functions-sequence">). This association can be modified or
- removed with <command>ALTER SEQUENCE OWNED BY</>. (The function
- probably should have been called
- <function>pg_get_owned_sequence</function>; its current name reflects the fact
- that it's typically used with <type>serial</> or <type>bigserial</>
- columns.)
+ with the column. If the column is an identity column, the associated
+ sequence is the sequence internally created for the identity column. For
+ columns created using one of the serial types
+ (<type>serial</type>, <type>smallserial</type>, <type>bigserial</type>), it
+ is the sequence created for that serial column definition. In the latter
+ case, this association can be modified or removed with <command>ALTER
+ SEQUENCE OWNED BY</>. (The function probably should have been called
+ <function>pg_get_owned_sequence</function>; its current name reflects the
+ fact that it has typically been used with <type>serial</>
+ or <type>bigserial</> columns.) The first input parameter is a table name
+ with optional schema, and the second parameter is a column name. Because
+ the first parameter is potentially a schema and table, it is not treated as
+ a double-quoted identifier, meaning it is lower cased by default, while the
+ second parameter, being just a column name, is treated as double-quoted and
+ has its case preserved. The function returns a value suitably formatted
+ for passing to sequence functions
+ (see <xref linkend="functions-sequence">). A typical use is in reading the
+ current value of a sequence for an identity or serial column, for example:
+<programlisting>
+SELECT currval(pg_get_serial_sequence('sometable', 'id'));
+</programlisting>
</para>
<para>
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 0ea50782181..84759b6149e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2322,7 +2322,7 @@ pg_get_userbyid(PG_FUNCTION_ARGS)
/*
* pg_get_serial_sequence
- * Get the name of the sequence used by a serial column,
+ * Get the name of the sequence used by an identity or serial column,
* formatted suitably for passing to setval, nextval or currval.
* First parameter is not treated as double-quoted, second parameter
* is --- see documentation for reason.
@@ -2380,13 +2380,14 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
/*
- * We assume any auto dependency of a sequence on a column must be
- * what we are looking for. (We need the relkind test because indexes
- * can also have auto dependencies on columns.)
+ * Look for an auto dependency (serial column) or internal dependency
+ * (identity column) of a sequence on a column. (We need the relkind
+ * test because indexes can also have auto dependencies on columns.)
*/
if (deprec->classid == RelationRelationId &&
deprec->objsubid == 0 &&
- deprec->deptype == DEPENDENCY_AUTO &&
+ (deprec->deptype == DEPENDENCY_AUTO ||
+ deprec->deptype == DEPENDENCY_INTERNAL) &&
get_rel_relkind(deprec->objid) == RELKIND_SEQUENCE)
{
sequenceId = deprec->objid;
diff --git a/src/test/regress/expected/identity.out b/src/test/regress/expected/identity.out
index 88b56dad93b..2800ed7caab 100644
--- a/src/test/regress/expected/identity.out
+++ b/src/test/regress/expected/identity.out
@@ -26,6 +26,12 @@ SELECT sequence_name FROM information_schema.sequences WHERE sequence_name LIKE
---------------
(0 rows)
+SELECT pg_get_serial_sequence('itest1', 'a');
+ pg_get_serial_sequence
+------------------------
+ public.itest1_a_seq
+(1 row)
+
CREATE TABLE itest4 (a int, b text);
ALTER TABLE itest4 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY; -- error, requires NOT NULL
ERROR: column "a" of relation "itest4" must be declared NOT NULL before identity can be added
diff --git a/src/test/regress/expected/sequence.out b/src/test/regress/expected/sequence.out
index a43b52cfc1e..ea05a3382b8 100644
--- a/src/test/regress/expected/sequence.out
+++ b/src/test/regress/expected/sequence.out
@@ -79,6 +79,12 @@ SELECT * FROM serialTest1;
force | 100
(3 rows)
+SELECT pg_get_serial_sequence('serialTest1', 'f2');
+ pg_get_serial_sequence
+---------------------------
+ public.serialtest1_f2_seq
+(1 row)
+
-- test smallserial / bigserial
CREATE TABLE serialTest2 (f1 text, f2 serial, f3 smallserial, f4 serial2,
f5 bigserial, f6 serial8);
diff --git a/src/test/regress/sql/identity.sql b/src/test/regress/sql/identity.sql
index a7e7b157371..7886456a569 100644
--- a/src/test/regress/sql/identity.sql
+++ b/src/test/regress/sql/identity.sql
@@ -12,6 +12,8 @@ SELECT table_name, column_name, column_default, is_nullable, is_identity, identi
-- internal sequences should not be shown here
SELECT sequence_name FROM information_schema.sequences WHERE sequence_name LIKE 'itest%';
+SELECT pg_get_serial_sequence('itest1', 'a');
+
CREATE TABLE itest4 (a int, b text);
ALTER TABLE itest4 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY; -- error, requires NOT NULL
ALTER TABLE itest4 ALTER COLUMN a SET NOT NULL;
diff --git a/src/test/regress/sql/sequence.sql b/src/test/regress/sql/sequence.sql
index b41c5a753dc..c50834a5b97 100644
--- a/src/test/regress/sql/sequence.sql
+++ b/src/test/regress/sql/sequence.sql
@@ -61,6 +61,8 @@ INSERT INTO serialTest1 VALUES ('wrong', NULL);
SELECT * FROM serialTest1;
+SELECT pg_get_serial_sequence('serialTest1', 'f2');
+
-- test smallserial / bigserial
CREATE TABLE serialTest2 (f1 text, f2 serial, f3 smallserial, f4 serial2,
f5 bigserial, f6 serial8);