Merge pull request #25 from akaariai/ticket_15933_alt

Made get_indexes() consistent across backends.
This commit is contained in:
Anssi Kääriäinen 2012-04-30 04:53:22 -07:00
commit c09f6ff0a5
7 changed files with 66 additions and 56 deletions

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@ -997,6 +997,17 @@ class BaseDatabaseIntrospection(object):
"""
raise NotImplementedError
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of indexed fieldname -> infodict for the given
table, where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
Only single-column indexes are introspected.
"""
raise NotImplementedError
class BaseDatabaseClient(object):
"""
This class encapsulates all backend-specific methods for opening a

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@ -85,15 +85,19 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
return None
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of fieldname -> infodict for the given table,
where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
"""
cursor.execute("SHOW INDEX FROM %s" % self.connection.ops.quote_name(table_name))
# Do a two-pass search for indexes: on first pass check which indexes
# are multicolumn, on second pass check which single-column indexes
# are present.
rows = list(cursor.fetchall())
multicol_indexes = set()
for row in rows:
if row[3] > 1:
multicol_indexes.add(row[2])
indexes = {}
for row in cursor.fetchall():
for row in rows:
if row[2] in multicol_indexes:
continue
indexes[row[4]] = {'primary_key': (row[2] == 'PRIMARY'), 'unique': not bool(row[1])}
return indexes

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@ -72,14 +72,14 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
FROM user_constraints, USER_CONS_COLUMNS ca, USER_CONS_COLUMNS cb,
user_tab_cols ta, user_tab_cols tb
WHERE user_constraints.table_name = %s AND
ta.table_name = %s AND
ta.table_name = user_constraints.table_name AND
ta.column_name = ca.column_name AND
ca.table_name = %s AND
ca.table_name = ta.table_name AND
user_constraints.constraint_name = ca.constraint_name AND
user_constraints.r_constraint_name = cb.constraint_name AND
cb.table_name = tb.table_name AND
cb.column_name = tb.column_name AND
ca.position = cb.position""", [table_name, table_name, table_name])
ca.position = cb.position""", [table_name])
relations = {}
for row in cursor.fetchall():
@ -87,36 +87,31 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
return relations
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of fieldname -> infodict for the given table,
where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
"""
# This query retrieves each index on the given table, including the
# first associated field name
# "We were in the nick of time; you were in great peril!"
sql = """\
SELECT LOWER(all_tab_cols.column_name) AS column_name,
sql = """
SELECT LOWER(uic1.column_name) AS column_name,
CASE user_constraints.constraint_type
WHEN 'P' THEN 1 ELSE 0
END AS is_primary_key,
CASE user_indexes.uniqueness
WHEN 'UNIQUE' THEN 1 ELSE 0
END AS is_unique
FROM all_tab_cols, user_cons_columns, user_constraints, user_ind_columns, user_indexes
WHERE all_tab_cols.column_name = user_cons_columns.column_name (+)
AND all_tab_cols.table_name = user_cons_columns.table_name (+)
AND user_cons_columns.constraint_name = user_constraints.constraint_name (+)
AND user_constraints.constraint_type (+) = 'P'
AND user_ind_columns.column_name (+) = all_tab_cols.column_name
AND user_ind_columns.table_name (+) = all_tab_cols.table_name
FROM user_constraints, user_indexes, user_ind_columns uic1
WHERE user_constraints.constraint_type (+) = 'P'
AND user_constraints.index_name (+) = uic1.index_name
AND user_indexes.uniqueness (+) = 'UNIQUE'
AND user_indexes.index_name (+) = user_ind_columns.index_name
AND all_tab_cols.table_name = UPPER(%s)
"""
AND user_indexes.index_name (+) = uic1.index_name
AND uic1.table_name = UPPER(%s)
AND uic1.column_position = 1
AND NOT EXISTS (
SELECT 1
FROM user_ind_columns uic2
WHERE uic2.index_name = uic1.index_name
AND uic2.column_position = 2
)
"""
cursor.execute(sql, [table_name])
indexes = {}
for row in cursor.fetchall():
indexes[row[0]] = {'primary_key': row[1], 'unique': row[2]}
indexes[row[0]] = {'primary_key': bool(row[1]),
'unique': bool(row[2])}
return indexes

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@ -65,12 +65,6 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
return relations
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of fieldname -> infodict for the given table,
where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
"""
# This query retrieves each index on the given table, including the
# first associated field name
cursor.execute("""

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@ -133,28 +133,22 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
return key_columns
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of fieldname -> infodict for the given table,
where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
"""
indexes = {}
for info in self._table_info(cursor, table_name):
indexes[info['name']] = {'primary_key': info['pk'] != 0,
if info['pk'] != 0:
indexes[info['name']] = {'primary_key': True,
'unique': False}
cursor.execute('PRAGMA index_list(%s)' % self.connection.ops.quote_name(table_name))
# seq, name, unique
for index, unique in [(field[1], field[2]) for field in cursor.fetchall()]:
if not unique:
continue
cursor.execute('PRAGMA index_info(%s)' % self.connection.ops.quote_name(index))
info = cursor.fetchall()
# Skip indexes across multiple fields
if len(info) != 1:
continue
name = info[0][2] # seqno, cid, name
indexes[name]['unique'] = True
indexes[name] = {'primary_key': False,
'unique': unique}
return indexes
def get_primary_key_column(self, cursor, table_name):

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@ -7,6 +7,9 @@ class Reporter(models.Model):
email = models.EmailField()
facebook_user_id = models.BigIntegerField(null=True)
class Meta:
unique_together = ('first_name', 'last_name')
def __unicode__(self):
return u"%s %s" % (self.first_name, self.last_name)

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@ -137,6 +137,15 @@ class IntrospectionTests(TestCase):
indexes = connection.introspection.get_indexes(cursor, Article._meta.db_table)
self.assertEqual(indexes['reporter_id'], {'unique': False, 'primary_key': False})
def test_get_indexes_multicol(self):
"""
Test that multicolumn indexes are not included in the introspection
results.
"""
cursor = connection.cursor()
indexes = connection.introspection.get_indexes(cursor, Reporter._meta.db_table)
self.assertNotIn('first_name', indexes)
self.assertIn('id', indexes)
def datatype(dbtype, description):
"""Helper to convert a data type into a string."""