1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
from django.db.backends.schema import BaseDatabaseSchemaEditor
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_create_sequence = "CREATE SEQUENCE %(sequence)s"
sql_delete_sequence = "DROP SEQUENCE IF EXISTS %(sequence)s CASCADE"
sql_set_sequence_max = "SELECT setval('%(sequence)s', MAX(%(column)s)) FROM %(table)s"
def quote_value(self, value):
# Inner import so backend fails nicely if it's not present
import psycopg2
return psycopg2.extensions.adapt(value)
def _alter_column_type_sql(self, table, column, type):
"""
Makes ALTER TYPE with SERIAL make sense.
"""
if type.lower() == "serial":
sequence_name = "%s_%s_seq" % (table, column)
return (
(
self.sql_alter_column_type % {
"column": self.quote_name(column),
"type": "integer",
},
[],
),
[
(
self.sql_delete_sequence % {
"sequence": sequence_name,
},
[],
),
(
self.sql_create_sequence % {
"sequence": sequence_name,
},
[],
),
(
self.sql_alter_column % {
"table": table,
"changes": self.sql_alter_column_default % {
"column": column,
"default": "nextval('%s')" % sequence_name,
}
},
[],
),
(
self.sql_set_sequence_max % {
"table": table,
"column": column,
"sequence": sequence_name,
},
[],
),
],
)
else:
return super(DatabaseSchemaEditor, self)._alter_column_type_sql(table, column, type)
|
