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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
import sqlalchemy.sql as sql
import sqlalchemy.engine as engine
import sqlalchemy.schema as schema
import sqlalchemy.ansisql as ansisql
import sqlalchemy.types as sqltypes
from sqlalchemy.exceptions import *
from sqlalchemy import *
from sqlalchemy.ansisql import *
generic_engine = ansisql.engine()
gen_schemata = schema.Table("schemata", generic_engine,
Column("catalog_name", String),
Column("schema_name", String),
Column("schema_owner", String),
schema="information_schema")
gen_tables = schema.Table("tables", generic_engine,
Column("table_catalog", String),
Column("table_schema", String),
Column("table_name", String),
Column("table_type", String),
schema="information_schema")
gen_columns = schema.Table("columns", generic_engine,
Column("table_schema", String),
Column("table_name", String),
Column("column_name", String),
Column("is_nullable", Integer),
Column("data_type", String),
Column("ordinal_position", Integer),
Column("character_maximum_length", Integer),
Column("numeric_precision", Integer),
Column("numeric_scale", Integer),
Column("column_default", Integer),
schema="information_schema")
gen_constraints = schema.Table("table_constraints", generic_engine,
Column("table_schema", String),
Column("table_name", String),
Column("constraint_name", String),
Column("constraint_type", String),
schema="information_schema")
gen_column_constraints = schema.Table("constraint_column_usage", generic_engine,
Column("table_schema", String),
Column("table_name", String),
Column("column_name", String),
Column("constraint_name", String),
schema="information_schema")
gen_key_constraints = schema.Table("key_column_usage", generic_engine,
Column("table_schema", String),
Column("table_name", String),
Column("column_name", String),
Column("constraint_name", String),
schema="information_schema")
gen_ref_constraints = schema.Table("referential_constraints", generic_engine,
Column("constraint_catalog", String),
Column("constraint_schema", String),
Column("constraint_name", String),
Column("unique_constraint_catlog", String),
Column("unique_constraint_schema", String),
Column("unique_constraint_name", String),
Column("match_option", String),
Column("update_rule", String),
Column("delete_rule", String),
schema="information_schema")
class ISchema(object):
def __init__(self, engine):
self.engine = engine
self.cache = {}
def __getattr__(self, name):
if name not in self.cache:
# This is a bit of a hack.
# It would probably be better to have a dict
# with just the information_schema tables at
# the module level, so as to avoid returning
# unrelated objects that happen to be named
# 'gen_*'
try:
gen_tbl = globals()['gen_'+name]
except KeyError:
raise ArgumentError('information_schema table %s not found' % name)
self.cache[name] = gen_tbl.toengine(self.engine)
return self.cache[name]
def reflecttable(engine, table, ischema_names, use_mysql=False):
columns = gen_columns.toengine(engine)
constraints = gen_constraints.toengine(engine)
if use_mysql:
# no idea which INFORMATION_SCHEMA spec is correct, mysql or postgres
key_constraints = schema.Table("key_column_usage", engine,
Column("table_schema", String),
Column("table_name", String),
Column("column_name", String),
Column("constraint_name", String),
Column("referenced_table_schema", String),
Column("referenced_table_name", String),
Column("referenced_column_name", String),
schema="information_schema", useexisting=True)
else:
column_constraints = gen_column_constraints.toengine(engine)
key_constraints = gen_key_constraints.toengine(engine)
if table.schema is not None:
current_schema = table.schema
else:
current_schema = engine.get_default_schema_name()
s = select([columns],
sql.and_(columns.c.table_name==table.name,
columns.c.table_schema==current_schema),
order_by=[columns.c.ordinal_position])
c = s.execute()
while True:
row = c.fetchone()
if row is None:
break
#print "row! " + repr(row)
# continue
(name, type, nullable, charlen, numericprec, numericscale, default) = (
row[columns.c.column_name],
row[columns.c.data_type],
row[columns.c.is_nullable] == 'YES',
row[columns.c.character_maximum_length],
row[columns.c.numeric_precision],
row[columns.c.numeric_scale],
row[columns.c.column_default]
)
args = []
for a in (charlen, numericprec, numericscale):
if a is not None:
args.append(a)
coltype = ischema_names[type]
#print "coltype " + repr(coltype) + " args " + repr(args)
coltype = coltype(*args)
colargs= []
if default is not None:
colargs.append(PassiveDefault(sql.text(default)))
table.append_item(schema.Column(name, coltype, nullable=nullable, *colargs))
s = select([constraints.c.constraint_name, constraints.c.constraint_type, constraints.c.table_name, key_constraints], use_labels=True, from_obj=[constraints.join(column_constraints, column_constraints.c.constraint_name==constraints.c.constraint_name).join(key_constraints, key_constraints.c.constraint_name==column_constraints.c.constraint_name)])
if not use_mysql:
s.append_column(column_constraints)
s.append_whereclause(constraints.c.table_name==table.name)
s.append_whereclause(constraints.c.table_schema==current_schema)
colmap = [constraints.c.constraint_type, key_constraints.c.column_name, column_constraints.c.table_schema, column_constraints.c.table_name, column_constraints.c.column_name]
else:
# this doesnt seem to pick up any foreign keys with mysql
s.append_whereclause(key_constraints.c.table_name==constraints.c.table_name)
s.append_whereclause(key_constraints.c.table_schema==constraints.c.table_schema)
s.append_whereclause(constraints.c.table_name==table.name)
s.append_whereclause(constraints.c.table_schema==current_schema)
colmap = [constraints.c.constraint_type, key_constraints.c.column_name, key_constraints.c.referenced_table_schema, key_constraints.c.referenced_table_name, key_constraints.c.referenced_column_name]
c = s.execute()
while True:
row = c.fetchone()
if row is None:
break
# continue
(type, constrained_column, referred_schema, referred_table, referred_column) = (
row[colmap[0]],
row[colmap[1]],
row[colmap[2]],
row[colmap[3]],
row[colmap[4]]
)
#print "type %s on column %s to remote %s.%s.%s" % (type, constrained_column, referred_schema, referred_table, referred_column)
if type=='PRIMARY KEY':
table.c[constrained_column]._set_primary_key()
elif type=='FOREIGN KEY':
remotetable = Table(referred_table, engine, autoload = True, schema=referred_schema)
table.c[constrained_column].append_item(schema.ForeignKey(remotetable.c[referred_column]))
|
