diff options
Diffstat (limited to 'django/db/backends/postgresql/base.py')
| -rw-r--r-- | django/db/backends/postgresql/base.py | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py index 912d49b493..2186fa3863 100644 --- a/django/db/backends/postgresql/base.py +++ b/django/db/backends/postgresql/base.py @@ -239,22 +239,27 @@ 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 |