318 lines
12 KiB
Python
318 lines
12 KiB
Python
from __future__ import unicode_literals
|
|
|
|
from collections import namedtuple
|
|
|
|
from django.db.backends.base.introspection import (
|
|
BaseDatabaseIntrospection, FieldInfo, TableInfo,
|
|
)
|
|
try:
|
|
# Django >= 1.11
|
|
from django.db.models.indexes import Index
|
|
except ImportError:
|
|
Index = None
|
|
from django.utils.encoding import force_text
|
|
|
|
fields = FieldInfo._fields
|
|
if 'default' not in fields:
|
|
fields += ('default',)
|
|
|
|
FieldInfo = namedtuple('FieldInfo', fields)
|
|
|
|
|
|
class DatabaseSchemaIntrospection(BaseDatabaseIntrospection):
|
|
# Maps type codes to Django Field types.
|
|
data_types_reverse = {
|
|
16: 'BooleanField',
|
|
17: 'BinaryField',
|
|
20: 'BigIntegerField',
|
|
21: 'SmallIntegerField',
|
|
23: 'IntegerField',
|
|
25: 'TextField',
|
|
700: 'FloatField',
|
|
701: 'FloatField',
|
|
869: 'GenericIPAddressField',
|
|
1042: 'CharField', # blank-padded
|
|
1043: 'CharField',
|
|
1082: 'DateField',
|
|
1083: 'TimeField',
|
|
1114: 'DateTimeField',
|
|
1184: 'DateTimeField',
|
|
1266: 'TimeField',
|
|
1700: 'DecimalField',
|
|
2950: 'UUIDField',
|
|
}
|
|
|
|
ignored_tables = []
|
|
|
|
_get_table_list_query = """
|
|
SELECT c.relname, c.relkind
|
|
FROM pg_catalog.pg_class c
|
|
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
|
|
WHERE c.relkind IN ('r', 'v')
|
|
AND n.nspname = %(schema)s;
|
|
"""
|
|
|
|
_get_table_description_query = """
|
|
SELECT column_name, is_nullable, column_default
|
|
FROM information_schema.columns
|
|
WHERE table_name = %(table)s
|
|
AND table_schema = %(schema)s
|
|
"""
|
|
|
|
_get_relations_query = """
|
|
SELECT c2.relname, a1.attname, a2.attname
|
|
FROM pg_constraint con
|
|
LEFT JOIN pg_class c1 ON con.conrelid = c1.oid
|
|
LEFT JOIN pg_class c2 ON con.confrelid = c2.oid
|
|
LEFT JOIN pg_attribute a1 ON c1.oid = a1.attrelid AND a1.attnum = con.conkey[1]
|
|
LEFT JOIN pg_attribute a2 ON c2.oid = a2.attrelid AND a2.attnum = con.confkey[1]
|
|
LEFT JOIN pg_catalog.pg_namespace n1 ON n1.oid = con.connamespace
|
|
WHERE c1.relname = %(table)s
|
|
AND n1.nspname = %(schema)s
|
|
AND con.contype = 'f'
|
|
"""
|
|
|
|
_get_key_columns_query = """
|
|
SELECT kcu.column_name, ccu.table_name AS referenced_table, ccu.column_name AS referenced_column
|
|
FROM information_schema.constraint_column_usage ccu
|
|
LEFT JOIN information_schema.key_column_usage kcu
|
|
ON ccu.constraint_catalog = kcu.constraint_catalog
|
|
AND ccu.constraint_schema = kcu.constraint_schema
|
|
AND ccu.constraint_name = kcu.constraint_name
|
|
LEFT JOIN information_schema.table_constraints tc
|
|
ON ccu.constraint_catalog = tc.constraint_catalog
|
|
AND ccu.constraint_schema = tc.constraint_schema
|
|
AND ccu.constraint_name = tc.constraint_name
|
|
WHERE kcu.table_name = %(table)s
|
|
AND kcu.table_schame = %(schema)s
|
|
AND tc.constraint_type = 'FOREIGN KEY'
|
|
"""
|
|
|
|
_get_indexes_query = """
|
|
SELECT attr.attname, idx.indkey, idx.indisunique, idx.indisprimary
|
|
FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
|
|
pg_catalog.pg_index idx, pg_catalog.pg_attribute attr
|
|
WHERE c.oid = idx.indrelid
|
|
AND idx.indexrelid = c2.oid
|
|
AND attr.attrelid = c.oid
|
|
AND attr.attnum = idx.indkey[0]
|
|
AND c.relname = %(table)s
|
|
AND n.nspname = %(schema)s
|
|
"""
|
|
|
|
_get_constraints_query = """
|
|
SELECT
|
|
c.conname,
|
|
array(
|
|
SELECT attname
|
|
FROM (
|
|
SELECT unnest(c.conkey) AS colid,
|
|
generate_series(1, array_length(c.conkey, 1)) AS arridx
|
|
) AS cols
|
|
JOIN pg_attribute AS ca ON cols.colid = ca.attnum
|
|
WHERE ca.attrelid = c.conrelid
|
|
ORDER BY cols.arridx
|
|
),
|
|
c.contype,
|
|
(SELECT fkc.relname || '.' || fka.attname
|
|
FROM pg_attribute AS fka
|
|
JOIN pg_class AS fkc ON fka.attrelid = fkc.oid
|
|
WHERE fka.attrelid = c.confrelid
|
|
AND fka.attnum = c.confkey[1]),
|
|
cl.reloptions
|
|
FROM pg_constraint AS c
|
|
JOIN pg_class AS cl ON c.conrelid = cl.oid
|
|
JOIN pg_namespace AS ns ON cl.relnamespace = ns.oid
|
|
WHERE ns.nspname = %(schema)s AND cl.relname = %(table)s
|
|
"""
|
|
|
|
_get_check_constraints_query = """
|
|
SELECT kc.constraint_name, kc.column_name
|
|
FROM information_schema.constraint_column_usage AS kc
|
|
JOIN information_schema.table_constraints AS c ON
|
|
kc.table_schema = c.table_schema AND
|
|
kc.table_name = c.table_name AND
|
|
kc.constraint_name = c.constraint_name
|
|
WHERE
|
|
c.constraint_type = 'CHECK' AND
|
|
kc.table_schema = %(schema)s AND
|
|
kc.table_name = %(table)s
|
|
"""
|
|
|
|
_get_index_constraints_query = """
|
|
SELECT
|
|
indexname, array_agg(attname ORDER BY rnum), indisunique, indisprimary,
|
|
array_agg(ordering ORDER BY rnum), amname, exprdef, s2.attoptions
|
|
FROM (
|
|
SELECT
|
|
row_number() OVER () as rnum, c2.relname as indexname,
|
|
idx.*, attr.attname, am.amname,
|
|
CASE
|
|
WHEN idx.indexprs IS NOT NULL THEN
|
|
pg_get_indexdef(idx.indexrelid)
|
|
END AS exprdef,
|
|
CASE am.amname
|
|
WHEN 'btree' THEN
|
|
CASE (option & 1)
|
|
WHEN 1 THEN 'DESC' ELSE 'ASC'
|
|
END
|
|
END as ordering,
|
|
c2.reloptions as attoptions
|
|
FROM (
|
|
SELECT
|
|
*, unnest(i.indkey) as key, unnest(i.indoption) as option
|
|
FROM pg_index i
|
|
) idx
|
|
LEFT JOIN pg_class c ON idx.indrelid = c.oid
|
|
LEFT JOIN pg_class c2 ON idx.indexrelid = c2.oid
|
|
LEFT JOIN pg_am am ON c2.relam = am.oid
|
|
LEFT JOIN pg_attribute attr ON attr.attrelid = c.oid AND attr.attnum = idx.key
|
|
LEFT JOIN pg_namespace n ON c.relnamespace = n.oid
|
|
WHERE c.relname = %(table)s
|
|
AND n.nspname = %(schema)s
|
|
) s2
|
|
GROUP BY indexname, indisunique, indisprimary, amname, exprdef, attoptions;
|
|
"""
|
|
|
|
def get_field_type(self, data_type, description):
|
|
field_type = super(DatabaseSchemaIntrospection, self).get_field_type(data_type, description)
|
|
if description.default and 'nextval' in description.default:
|
|
if field_type == 'IntegerField':
|
|
return 'AutoField'
|
|
elif field_type == 'BigIntegerField':
|
|
return 'BigAutoField'
|
|
return field_type
|
|
|
|
def get_table_list(self, cursor):
|
|
"""
|
|
Returns a list of table and view names in the current schema.
|
|
"""
|
|
cursor.execute(self._get_table_list_query, {
|
|
'schema': self.connection.schema_name
|
|
})
|
|
|
|
return [
|
|
TableInfo(row[0], {'r': 't', 'v': 'v'}.get(row[1]))
|
|
for row in cursor.fetchall()
|
|
if row[0] not in self.ignored_tables
|
|
]
|
|
|
|
def get_table_description(self, cursor, table_name):
|
|
"""
|
|
Returns a description of the table, with the DB-API cursor.description interface.
|
|
"""
|
|
|
|
# As cursor.description does not return reliably the nullable property,
|
|
# we have to query the information_schema (#7783)
|
|
cursor.execute(self._get_table_description_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name
|
|
})
|
|
field_map = {line[0]: line[1:] for line in cursor.fetchall()}
|
|
cursor.execute('SELECT * FROM %s LIMIT 1' % self.connection.ops.quote_name(table_name))
|
|
|
|
return [
|
|
FieldInfo(*(
|
|
(force_text(line[0]),) +
|
|
line[1:6] +
|
|
(field_map[force_text(line[0])][0] == 'YES', field_map[force_text(line[0])][1])
|
|
)) for line in cursor.description
|
|
]
|
|
|
|
def get_relations(self, cursor, table_name):
|
|
"""
|
|
Returns a dictionary of {field_name: (field_name_other_table, other_table)}
|
|
representing all relationships to the given table.
|
|
"""
|
|
cursor.execute(self._get_relations_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name
|
|
})
|
|
relations = {}
|
|
for row in cursor.fetchall():
|
|
relations[row[1]] = (row[2], row[0])
|
|
|
|
return relations
|
|
|
|
def get_key_columns(self, cursor, table_name):
|
|
cursor.execute(self._get_key_columns_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name
|
|
})
|
|
return list(cursor.fetchall())
|
|
|
|
def get_indexes(self, cursor, table_name):
|
|
# This query retrieves each index on the given table, including the
|
|
# first associated field name
|
|
cursor.execute(self._get_indexes_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name,
|
|
})
|
|
indexes = {}
|
|
for row in cursor.fetchall():
|
|
# row[1] (idx.indkey) is stored in the DB as an array. It comes out as
|
|
# a string of space-separated integers. This designates the field
|
|
# indexes (1-based) of the fields that have indexes on the table.
|
|
# Here, we skip any indexes across multiple fields.
|
|
if ' ' in row[1]:
|
|
continue
|
|
if row[0] not in indexes:
|
|
indexes[row[0]] = {'primary_key': False, 'unique': False}
|
|
# It's possible to have the unique and PK constraints in separate indexes.
|
|
if row[3]:
|
|
indexes[row[0]]['primary_key'] = True
|
|
if row[2]:
|
|
indexes[row[0]]['unique'] = True
|
|
return indexes
|
|
|
|
def get_constraints(self, cursor, table_name):
|
|
"""
|
|
Retrieves any constraints or keys (unique, pk, fk, check, index) across
|
|
one or more columns. Also retrieve the definition of expression-based
|
|
indexes.
|
|
"""
|
|
constraints = {}
|
|
# Loop over the key table, collecting things as constraints. The column
|
|
# array must return column names in the same order in which they were
|
|
# created
|
|
# The subquery containing generate_series can be replaced with
|
|
# "WITH ORDINALITY" when support for PostgreSQL 9.3 is dropped.
|
|
cursor.execute(self._get_constraints_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name,
|
|
})
|
|
|
|
for constraint, columns, kind, used_cols, options in cursor.fetchall():
|
|
constraints[constraint] = {
|
|
"columns": columns,
|
|
"primary_key": kind == "p",
|
|
"unique": kind in ["p", "u"],
|
|
"foreign_key": tuple(used_cols.split(".", 1)) if kind == "f" else None,
|
|
"check": kind == "c",
|
|
"index": False,
|
|
"definition": None,
|
|
"options": options,
|
|
}
|
|
|
|
# Now get indexes
|
|
cursor.execute(self._get_index_constraints_query, {
|
|
'schema': self.connection.schema_name,
|
|
'table': table_name,
|
|
})
|
|
|
|
for index, columns, unique, primary, orders, type_, definition, options in cursor.fetchall():
|
|
if index not in constraints:
|
|
constraints[index] = {
|
|
"columns": columns if columns != [None] else [],
|
|
"orders": orders if orders != [None] else [],
|
|
"primary_key": primary,
|
|
"unique": unique,
|
|
"foreign_key": None,
|
|
"check": False,
|
|
"index": True,
|
|
"type": Index.suffix if type_ == 'btree' and Index else type_,
|
|
"definition": definition,
|
|
"options": options,
|
|
}
|
|
return constraints
|