Fixed #4432 -- Fixed PostgreSQL sequence resetting in the case when a table has

no rows yet. Thanks, mrmachine.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@5455 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Malcolm Tredinnick 2007-06-10 03:31:26 +00:00
parent 03ecc00f6e
commit 86fd59cfa5
3 changed files with 19 additions and 8 deletions

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@ -170,6 +170,7 @@ answer newbie questions, and generally made Django that much better:
mitakummaa@gmail.com mitakummaa@gmail.com
mmarshall mmarshall
Eric Moritz <http://eric.themoritzfamily.com/> Eric Moritz <http://eric.themoritzfamily.com/>
mrmachine <real.human@mrmachine.net>
Robin Munn <http://www.geekforgod.com/> Robin Munn <http://www.geekforgod.com/>
Robert Myers <myer0052@gmail.com> Robert Myers <myer0052@gmail.com>
Nebojša Dorđević Nebojša Dorđević

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@ -219,22 +219,27 @@ def get_sql_sequence_reset(style, model_list):
from django.db import models from django.db import models
output = [] output = []
for model in model_list: 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: for f in model._meta.fields:
if isinstance(f, models.AutoField): 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_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))), 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_FIELD(quote_name(f.column)),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'), style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(quote_name(model._meta.db_table)))) style.SQL_TABLE(quote_name(model._meta.db_table))))
break # Only one AutoField is allowed per model, so don't bother continuing. break # Only one AutoField is allowed per model, so don't bother continuing.
for f in model._meta.many_to_many: 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_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())), 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_FIELD(quote_name('id')),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'), style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(f.m2m_db_table()))) style.SQL_TABLE(f.m2m_db_table())))
return output return output

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@ -176,22 +176,27 @@ def get_sql_sequence_reset(style, model_list):
from django.db import models from django.db import models
output = [] output = []
for model in model_list: 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: for f in model._meta.fields:
if isinstance(f, models.AutoField): 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_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))), 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_FIELD(quote_name(f.column)),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'), style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(quote_name(model._meta.db_table)))) style.SQL_TABLE(quote_name(model._meta.db_table))))
break # Only one AutoField is allowed per model, so don't bother continuing. break # Only one AutoField is allowed per model, so don't bother continuing.
for f in model._meta.many_to_many: 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_KEYWORD('SELECT'),
style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())), 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_FIELD(quote_name('id')),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'), style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(f.m2m_db_table()))) style.SQL_TABLE(f.m2m_db_table())))
return output return output