diff --git a/AUTHORS b/AUTHORS
index bff482f294..01f7983e36 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -170,6 +170,7 @@ answer newbie questions, and generally made Django that much better:
mitakummaa@gmail.com
mmarshall
Eric Moritz
+ mrmachine
Robin Munn
Robert Myers
Nebojša Dorđević
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index a5b38a883d..fedbb6b7f1 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -219,22 +219,27 @@ def get_sql_sequence_reset(style, model_list):
from django.db import models
output = []
for model in model_list:
+ # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+ # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+ # if there are records (as the max pk value is already in use), otherwise set it to false.
for f in model._meta.fields:
if isinstance(f, models.AutoField):
- output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
(style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
- style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name(f.column)),
+ style.SQL_FIELD(quote_name(f.column)),
+ style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(quote_name(model._meta.db_table))))
break # Only one AutoField is allowed per model, so don't bother continuing.
for f in model._meta.many_to_many:
- output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
(style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
- style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('id')),
+ style.SQL_FIELD(quote_name('id')),
+ style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(f.m2m_db_table())))
return output
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 9898b121f4..d9ad363ac1 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -176,22 +176,27 @@ def get_sql_sequence_reset(style, model_list):
from django.db import models
output = []
for model in model_list:
+ # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+ # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+ # if there are records (as the max pk value is already in use), otherwise set it to false.
for f in model._meta.fields:
if isinstance(f, models.AutoField):
- output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
(style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
- style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name(f.column)),
+ style.SQL_FIELD(quote_name(f.column)),
+ style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(quote_name(model._meta.db_table))))
break # Only one AutoField is allowed per model, so don't bother continuing.
for f in model._meta.many_to_many:
- output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
(style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
- style.SQL_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('id')),
+ style.SQL_FIELD(quote_name('id')),
+ style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(f.m2m_db_table())))
return output